Final California 2012 Integrated Report( 303(d) List/305(b) Report)

Supporting Information

Regional Board 7 - Colorado River Basin Region

Water Body Name:	Imperial Valley Drains
Water Body ID:	CAR7231000019990205150323
Water Body Type:	River & Stream

DECISION ID	18966	Region 7
Imperial Valley Drains

Pollutant:	Endosulfan
Final Listing Decision:	Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Reason for Delisting:	Applicable WQS attained; reason for recovery unspecified
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4.11 of the Listing Policy. Under this section when all other delisting factors do not result in the delisting of a water segment but information indicates attainment of standards, a water segment shall be evaluated to determine whether the weight of evidence demonstrates that water quality standard is attained. If the weight of evidence indicates attainment, the water segment shall be removed from the section 303(d) list. Four lines of evidence are available in the administrative record to assess pollutant. LOE No. 46183 is combined with LOE No. 5607 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. Ten of samples exceed the water quality objective, and the exceedances were occurred from 1985 to 1996. Organochlorine (OC) pesticides are man-made chemicals. There are no natural sources of these OC compounds. Endosulfan is one of the OC compounds, which was used for mainly agricultural uses during 1980s and 1990s. However, USEPA has initiated action to end the use of Endosulfan based on the Endosulfan Memorandum of Agreement in 2010. The use of Endosulfan is phasing out, and the registrants of Endosulfan are voluntarily cancelling all existing Endosulfan uses. Since OC compounds are attached to sediments, sediment management practices (MPs) plays important roles in reducing the compounds. A USEPA approved TMDL, Imperial Valley Drains (IVDs) Sediment TMDL and Prohibition, is already in place in Imperial County, which requires farmers/growers to implement improved sediment MPs. According to the CA Department of Pesticide Regulations (DPR) pesticide use reporting (PUR), the annual use of Endosulfan in Imperial County, where this waterbody is located, is significantly reduced past 20 years. The reported annual Endosulfan uses were 247, 400 pounds in 1990, and the amount reduced to 22 pounds in 2010. Although the use of Endosulfan for Alfalfa seed, which is the major crop produced in the Imperial County, will be ended by July 31, 2016, the farmers in Imperial County have stopped its uses since 2011. No uses of Endosulfan were reported in the PUR in 2011 in the Imperial County. In addition, seven additional fish tissue samples, which were not included in the current assessment cycle due to data solicitation cutoff date, were collected by the SWAMP and CA Department of Fish and Game (DFG) in 2011, and none of the samples exceeded applicable water quality objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. Ten of 44 fish tissue samples exceeded the NAS fish tissue guideline and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. However, the uses of Endosulfan is phasing out; the farmers have stopped using the Endosulfan for Alfalfa seed since 2011; the last exceedance was occurred on 11/3/1996; and more recent data, collected from 1999-2011, indicates that the water quality standard is attained. 3. This process is scientifically defensible and reproducible.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 18966, Endosulfan Region 7      Imperial Valley Drains
LOE ID:	5607
Pollutant:	Endosulfan
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	10
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, 6 fish fillet samples and 4 whole fish samples collected at 6 locations exceeded the NAS tissue guideline. At Rose drain exceedances were found in 1 carp fillet composite sample collected on 11/17/1998, and 1 mosquitofish whole fish composite sample collected on 8/17/1991. At South Central drain an exceedance was found in 1 carp single fish fillet sample collected on 8/01/1990. At Rice drain 3 exceedances were found in 2 carp fillet composite samples collected on 10/10/1985, and 10/15/1986. At Pumice drain exceedances were found in 1 channel catfish fillet composite sample collected on 11/20/1990, and 1 carp fillet composite sample collected on 11/20/1990. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample collected on 8/16/19991. At Peach drain exceedences were found in 1 mosquitofish whole fish composite sample collected on 11/03/1996, and 1 sailfin molly whole fish composite sample collected on 9/17/1992 (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. Exceedances were found in samples collected from 10/10/1985 through 11/17/1998.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 18966, Endosulfan Region 7      Imperial Valley Drains
LOE ID:	5533
Pollutant:	Endosulfan
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the OEHHA Screening Value. (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 20,000 ug/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 18966, Endosulfan Region 7      Imperial Valley Drains
LOE ID:	46182
Pollutant:	Endosulfan
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Endosulfan, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total endosulfan was calculated as the sum of endosulfan l and endosulfan ll. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for endosulfan (l and ll) in fish tissue is 13,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 18966, Endosulfan Region 7      Imperial Valley Drains
LOE ID:	46183
Pollutant:	Endosulfan
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Endosulfan, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total endosulfan was calculated as the sum of endosulfan l and endosulfan ll. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum total Endosulfan concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	19120	Region 7
Imperial Valley Drains

Pollutant:	Chlordane
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Sources:	Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2 and 4.5 of the Listing Policy. Under these sections of the Policy, a minimum of one line of evidence is needed to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. LOE No. 5438 is replaced by the LOE No. 46768, which is assessed based on current evaluation guideline. Therefore, LOE No. 5438 is not included in the final use rating. LOE No. 46001 is combined with LOE No. 5581 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. LOE No. 34768 is combined with LOE No. 7652 for the aforementioned reasons. LOE No. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty-three of 44 fish tissue samples exceeded the modified OEHHA fish contaminant goal and these exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 19120, Chlordane Region 7      Imperial Valley Drains
LOE ID:	46768
Pollutant:	Chlordane
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	20
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish tissue samples were generally collected from 10/1985 through 11/2000. Of these total samples, 9 fish fillet samples and 10 whole fish samples collected at 10 locations exceeded the OEHHA Fish Contaminant Goal. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples collected on 10/28/1989, and 12/05/1999. At Central drain exceedances were found in 1 carp fillet composite sample collected on 12/05/1999, and 1 sailfin molly whole fish composite sample collected on 11/08/2000. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample collected on 12/05/1999, and 1 carp single fish fillet collected on 8/01/1990. At Rice drain 3 an exceedance was found in 1 carp fillet composite sample collected on 10/10/1985. At Greeson exceedances were found in 1 carp fillet composite sample collected on 11/15/1985, 1 spiny soft-shelled turtle collected on 9/18/1992, and 1 mosquitofish whole fish composite sample collected on 11/07/2000. At Pumice drain an exceedance was found in 1 channel catfish fillet composite sample collected on 11/20/1990. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample collected on 8/16/1991. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples collected on 10/28/1995, and 11/03/1996, and 1 sailfin molly whole fish composite sample collected on 9/17/1992. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples collected on (2)11/08/2000, and 1 sailfin molly whole fish composite sample collected on 9/17/1992. At Warren Drain an exceedance was found in 1 mosquitofish whole fish composite sample collected on 9/09/1990 (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for total chlordane in fish tissue is 3.9 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. The exceedances were found in samples collected from 10/10/1985 through 11/08/2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 19120, Chlordane Region 7      Imperial Valley Drains
LOE ID:	5438
Pollutant:	Chlordane
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	19
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish tissue samples were generally collected from 10/1985 through 11/2000. Of these total samples, 9 fish fillet samples and 10 whole fish samples collected at 10 locations exceeded the OEHHA Fish Contaminant Goal. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples collected on 10/28/1989, and 12/05/1999. At Central drain exceedances were found in 1 carp fillet composite sample collected on 12/05/1999, and 1 sailfin molly whole fish composite sample collected on 11/08/2000. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample collected on 12/05/1999, and 1 carp single fish fillet collected on 8/01/1990. At Rice drain 3 an exceedance was found in 1 carp fillet composite sample collected on 10/10/1985. At Greeson exceedances were found in 1 carp fillet composite sample collected on 11/15/1985, 1 spiny soft-shelled turtle collected on 9/18/1992, and 1 mosquitofish whole fish composite sample collected on 11/07/2000. At Pumice drain an exceedance was found in 1 channel catfish fillet composite sample collected on 11/20/1990. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample collected on 8/16/1991. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples collected on 10/28/1995, and 11/03/1996, and 1 sailfin molly whole fish composite sample collected on 9/17/1992. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples collected on (2)11/08/2000, and 1 sailfin molly whole fish composite sample collected on 9/17/1992. At Warren Drain an exceedance was found in 1 mosquitofish whole fish composite sample collected on 9/09/1990 (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 5.6 ug/kg to protect human health when consuming fish (OEHHA, 2008).
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. The exceedances were found in samples collected from 10/10/1985 through 11/08/2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 19120, Chlordane Region 7      Imperial Valley Drains
LOE ID:	5581
Pollutant:	Chlordane
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	1
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, 1 fish fillet samples collected at 1 location exceeded the NAS tissue guideline. At Rice drain 3 an exceedence was found in 1 carp fillet composite sample collected on 10/10/1985. (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. An exceedance was found in a sample collected on 10/10/1985.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 19120, Chlordane Region 7      Imperial Valley Drains
LOE ID:	46000
Pollutant:	Chlordane
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	3
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 3 of 4 samples exceed the criterion for Chlordane, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total chlordane was calculated as the sum of the following chlordane isomers: cis- and trans-chlordane, cis- and trans-nonachlor, and oxychlordane. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for total chlordane in fish tissue is 3.9 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19120, Chlordane Region 7      Imperial Valley Drains
LOE ID:	46001
Pollutant:	Chlordane
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Chlordane, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total chlordane was calculated as the sum of the following chlordane isomers: cis- and trans-chlordane, cis- and trans-nonachlor, and oxychlordane. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum total Chlordane concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	22439	Region 7
Imperial Valley Drains

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Sources:	Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2 and 4.5 of the Listing Policy. Under these sections of the Policy, a minimum of one line of evidence is needed to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Thirty-nine of 40 fish tissue samples exceeded the OEHHA fish contaminant goal, and four of four fish tissue samples exceeded the modified OEHHA fish contaminant goal, and none of six water samples exceeded the CTR criteria. These exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 22439, DDT (Dichlorodiphenyltrichloroethane) Region 7      Imperial Valley Drains
LOE ID:	5439
Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	39
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, 20 fish fillet samples and 19 whole fish samples collected at 15 locations exceeded the OEHHA Fish Contaminant Goal. At Rose drain exceedances were found in 1 carp fillet composite sample, and 1 mosquitofish whole fish composite sample. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples, 1 tilapia fillet compostie sample, and 1 carp fillet composite sample. At Central drain exceedances were found in 1 carp fillet composite sample, 1 flathead catfish single fish fillet sample, and 1 sailfin molly whole fish composite sample. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample, 1 carp single fish fillet sample, 1 spiny soft shelled turtle fillet composite sample, and 1 sailfin molly whole fish composite sample. At Rice drain 3 exceedances were found in 2 carp fillet composite samples. At Verde drain an exceedance was found in 1 carp single fish fillet sample. At Greeson exceedances were found in 1 carp fillet composite sample, 1 yellow bullhead fillet composite sample, 1 spiny soft shelled turtle fillet composite sample, and 1 mosquitofish whole fish composite sample. At Fig drain exceedances were found in 1 carp fillet composite sample, 1 mosquitofish whole fish composite sample, and 3 sailfin molly whole fish composite samples. At Pumice drain exceedances were found in 1 channel catfish fillet composite sample, 1 tilapia fish composite sample, and 1 carp fillet composite sample. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Orange drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Tokay drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Warren drain exceedances were found in 2 mosquitofish whole fish composite samples (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 21 ug/kg to protect human health when consuming fish (OEHHA, 2008).
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. The exceedances were found in samples collected from 9/10/1985 through 12/05/1999.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 22439, DDT (Dichlorodiphenyltrichloroethane) Region 7      Imperial Valley Drains
LOE ID:	5591
Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	14
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, 5 fish fillet samples and 9 whole fish samples collected at 9 locations exceeded the NAS tissue guideline. At Central drain an exceedance was found in 1 carp fillet composite sample. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample, 1 carp single fish fillet sample. At Rice drain 3 exceedances were found in 1 carp fillet composite sample. At Greeson an exceedance was found in 1 mosquitofish whole fish composite sample. At Pumice drain an exceedance was found in 1 channel catfish fillet composite sample. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Peach drain exceedances were found in 2 mosquitofish whole fish composites, and 1 sailfin molly whole fish composite sample. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composites. At Warren Drain exceedances were found in 2 mosquitofish whole fish composites (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 1000 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. Exceedances were found in samples collected from 10/10/1985 through 11/08/2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 22439, DDT (Dichlorodiphenyltrichloroethane) Region 7      Imperial Valley Drains
LOE ID:	46165
Pollutant:	Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	4
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 4 of 4 samples exceed the criterion for DDT, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total DDT was calculated as the sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for total DDT in fish tissue is 15 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 22439, DDT (Dichlorodiphenyltrichloroethane) Region 7      Imperial Valley Drains
LOE ID:	46166
Pollutant:	Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for DDT, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total DDT was calculated as the sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum total DDT concentration of 1000 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 22439, DDT (Dichlorodiphenyltrichloroethane) Region 7      Imperial Valley Drains
LOE ID:	5058
Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentration (CMC) of 1.1 ug/l for the protection of freshwater aquatic life uses (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	19124	Region 7
Imperial Valley Drains

Pollutant:	Dieldrin
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Sources:	Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2 and 4.5 of the Listing Policy. Under these sections of the Policy, a minimum of one line of evidence is needed to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. LOE No. 46181 is combined with LOE No. 5600 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Thirty six of 36 fish tissue samples exceeded the OEHHA fish contaminant goal, and four of 44 fish tissue samples exceeded the NAS fish tissue evaluation guideline. These exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 19124, Dieldrin Region 7      Imperial Valley Drains
LOE ID:	46181
Pollutant:	Dieldrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Dieldrin. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum Dieldrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19124, Dieldrin Region 7      Imperial Valley Drains
LOE ID:	5060
Pollutant:	Chromium (total) | Dieldrin | Endrin
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: 1724 ug/l Chromium, 0.24 ug/l Dieldrin, and 0.086 ug/l Endrin (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19124, Dieldrin Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19124, Dieldrin Region 7      Imperial Valley Drains
LOE ID:	5440
Pollutant:	Dieldrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	36
Number of Exceedances:	36
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. Four fish fillet sample results could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The 17 fish fillet samples and 19 whole fish samples that were acceptable were generally collected from 5/1986 through 11/2000. Of these total samples, 17 fish fillet samples and 19 whole fish samples collected at 15 locations exceeded the OEHHA Fish Contaminant Goal. At Rose drain exceedances were found in 1 carp fillet composite sample, and 1 mosquitofish whole fish composite sample. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples, and 1 carp fillet composite sample. At Central drain exceedances were found in 1 carp fillet composite sample, 1 flathead catfish single fish fillet sample, and 1 sailfin molly whole fish composite sample. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample, 1 carp single fish fillet sample, 1 spiny soft shelled turtle fish composite sample, and 1 sailfin molly whole fish composite sample. At Rice drain 3 exceedances were found in 2 carp fillet composite samples. At Verde drain an exceedance was found in 1 carp single fish fillet sample. At Greeson exceedances were found in 1 carp fillet composite sample, 1 yellow bullhead fillet composite sample, 1 spiny soft shelled turtle fillet composite sample, and 1 mosquitofish whole fish composite sample. At Fig drain exceedances were found in 1 mosquitofish whole fish composite sample, and 3 sailfin molly whole fish composite samples. At Pumice drain exceedances were found in 1 channel catfish fillet composite sample, and 1 carp fillet composite sample. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Orange drain an exceedance was found in 1 mosquitofish whole fish composite. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Tokay drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Warren Drain exceedances were found in 2 mosquitofish whole fish composite samples (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 0.46 ug/kg to protect human health when consuming fish (OEHHA, 2008).
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. The exceedances were found in samples collected from 9/10/1985 through 12/05/1999.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 19124, Dieldrin Region 7      Imperial Valley Drains
LOE ID:	5600
Pollutant:	Dieldrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	4
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, 1 fish fillet samples and 3 whole fish samples collected at 3 locations exceeded the NAS tissue guideline. At Rice drain 3 an exceedance was found in 1 carp fillet composite sample collected on 10/10/1985. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples collected on 10/28/1995, and 9/17/1992. At Warren drain an exceedance was found in 1 mosquitofish whole fish composite sample collected on 10/26/1989 (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. Exceedances were found in samples collected from 10/10/1985 through 10/28/1995.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 19124, Dieldrin Region 7      Imperial Valley Drains
LOE ID:	46168
Pollutant:	Dieldrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	4
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 4 of 4 samples exceed the criterion for Dieldrin. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for dieldrin in fish tissue is 0.32 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	19472	Region 7
Imperial Valley Drains

Pollutant:	PCBs (Polychlorinated biphenyls)
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Sources:	Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2 and 4.5 of the Listing Policy. Under these sections of the Policy, a minimum of one line of evidence is needed to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. LOE No. 46243 is combined with LOE No. 5647 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eight of 8 fish tissue samples exceeded the OEHHA fish contaminant goal, and three of four fish tissue samples exceeded the modified OEHHA fish tissue evaluation guideline. Two of two water samples exceeded the CTR criteria. These exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4..Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 19472, PCBs (Polychlorinated biphenyls) Region 7      Imperial Valley Drains
LOE ID:	46243
Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for PCB, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites were averaged for species collected at the same time and location. Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum total PCB concentration of 500 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19472, PCBs (Polychlorinated biphenyls) Region 7      Imperial Valley Drains
LOE ID:	4871
Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	2
Number of Exceedances:	2
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water samples were taken at three Imperial Valley Drains, 4 water sample results could not be used because the sample results were non-detect and the detection limit was above the criteria concentration. The two acceptable water quality samples were collected on 5/08/2002 and 5/09/2002, from W and Trifolium TD1 Imperial Valley Drains. These samples exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria of 0.00017 ug/l for the protection of human health when consuming organisms from aquatic systems (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains; Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were collected and analyzed in May and October 2002.The exceedences were found in samples collected from 5/08/2002 through 5/09/2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19472, PCBs (Polychlorinated biphenyls) Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19472, PCBs (Polychlorinated biphenyls) Region 7      Imperial Valley Drains
LOE ID:	5441
Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	8
Number of Exceedances:	8
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. Eighteen fish fillet and 14 whole fish sample results could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The 3 fish fillet samples and 5 whole fish samples that were acceptable were generally collected from 12/1999 through 11/2000. Of these total samples, 3 fish fillet samples and 5 whole fish samples collected at 5 locations exceeded the OEHHA Fish Contaminant Goal. At Holtville Main drain an exceedance was found in 1 channel catfish fillet composite sample collected on 12/05/1999. At Central drain exceedances were found in 1 carp fillet composite sample collected on 12/05/1999, and 1 sailfin molly whole fish composite sample collected on 11/08/2000. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample collected on 12/05/1999, and 1 sailfin molly whole fish composite sample collected on 11/08/2000. At Greeson an exceedance was found in 1 mosquitofish whole fish composite sample collected on 11/07/2000. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples collected on (2)11/08/2000 (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 3.6 ug/kg to protect human health when consuming fish (OEHHA, 2008).
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. The exceedances were found in samples collected from 12/05/1999 through 11/08/2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 19472, PCBs (Polychlorinated biphenyls) Region 7      Imperial Valley Drains
LOE ID:	5647
Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in imperial valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the NAS tissue guideline. (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 500 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 19472, PCBs (Polychlorinated biphenyls) Region 7      Imperial Valley Drains
LOE ID:	46230
Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	3
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 3 of 4 samples exceed the criterion for PCB, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites were averaged for species collected at the same time and location. Composites comprised of 2-3 fish for channel catfish and 1 fish for Tilapia spp. and flathead catfish. Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for polychlorinated biphenyls in fish tissue is 2.6 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	19123	Region 7
Imperial Valley Drains

Pollutant:	Toxaphene
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Sources:	Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2 and 4.5 of the Listing Policy. Under these sections of the Policy, a minimum of one line of evidence is needed to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. LOE No. 46246 is combined with LOE No. 5658 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty-three of 23 fish tissue samples exceeded the OEHHA fish contaminant goal, and 21 of 44 fish tissue samples exceeded the NAS fish tissue evaluation guideline. These exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 19123, Toxaphene Region 7      Imperial Valley Drains
LOE ID:	5658
Pollutant:	Toxaphene
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	21
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, 12 fish fillet samples and 9 whole fish samples collected at 12 locations exceeded the NAS tissue guideline. At Rose drain an exceedance was found in 1 carp fillet composite sample. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples. At Central drain an exceedance was found in 1 carp fillet composite sample. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample, 1 carp single fish fillet sample, and 1 sailfin molly whole fish composite. At Rice drain 3 exceedances were found in 2 carp fillet composite samples. At Verde drain an exceedance was found in 1 carp single fish fillet. At Greeson exceedances were found in 1 carp fillet composite sample, and 1 yellow bullhead fillet composite sample. At Pumice drain exceedances were found in 1 channel catfish fillet composite sample. At Mayflower drain an exceedence was found in 1 mosquitofish whole fish composite sample. At Orange drain an exceedance was found in 1 mosquitofish whole fish composite. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. Exceedances were found in samples collected from 10/10/1985 through 11/08/2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 19123, Toxaphene Region 7      Imperial Valley Drains
LOE ID:	46246
Pollutant:	Toxaphene
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Toxaphene. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum Toxaphene concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19123, Toxaphene Region 7      Imperial Valley Drains
LOE ID:	46245
Pollutant:	Toxaphene
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Eleven samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for toxaphene in fish tissue is 4.3 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19123, Toxaphene Region 7      Imperial Valley Drains
LOE ID:	5442
Pollutant:	Toxaphene
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	23
Number of Exceedances:	23
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. Nine fish fillet and eight whole fish sample results could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentrations. The 12 fish fillet samples and 11 whole fish samples that were acceptable were generally collected from 12/1922 through 11/2000. Of these total samples, 12 fish fillet samples and 11 whole fish samples collected at 12 locations exceeded the OEHHA Fish Contaminant Goal. At Rose drain an exceedance was found in 1 carp fillet composite sample. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples. At Central drain exceedances were found in 1 carp fillet composite sample, and 1 sailfin molly whole fish composite sample. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample, 1 carp single fish fillet sample, and 1 sailfin molly whole fish composite sample. At Rice drain 3 exceedances were found in 2 carp fillet composite samples. At Verde drain an exceedance was found in 1 carp single fish fillet sample. At Greeson drain exceedances were found in 1 carp fillet composite sample, 1 yellow bullhead fillet composite sample, and 1 mosquitofish whole fish composite sample. At Pumice drain an exceedance was found in 1 channel catfish fillet composite sample. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Orange drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 6.1 ug/kg to protect human health when consuming fish (OEHHA, 20008).
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000. The exceedances were found in samples collected from 10/10/1985 through 12/05/1999.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 19123, Toxaphene Region 7      Imperial Valley Drains
LOE ID:	2958
Pollutant:	Toxaphene
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	5
Number of Exceedances:	5
Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Five out of 5 samples exceeded the NAS guideline. A total of 5 whole fish composite samples of mosquitofish and sailfin molly were collected. Two mosquitofish samples were collected in 2000 and 3 sailfin molly samples were collected in 1992 and 2001-02. The guideline was exceeded in all samples (TSMP, 2002). Two out of 2 samples exceeded the OEHHA guideline. One filet composite sample (1999) and 1 individual filet sample (2002) of carp were collected. Both samples were in exceedance. Three out of 3 samples exceeded the NAS guideline. A total of 3 whole fish composite samples of sailfin molly and mosquitofish were collected. One sailfin molly sample was collected in 1992 and 2 mosquitofish samples were collected in 1995-96. The guideline was exceeded in all samples.
Data Reference:	Placeholder reference 2006 303(d)
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Colorado River Basin RWQCB Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.
Objective/Criterion Reference:	Placeholder reference 2006 303(d)
Evaluation Guideline:	NAS Guideline (whole fish) 100 ng/g and OEHHA Screening Value 30 ng/g.
Guideline Reference:	Placeholder reference 2006 303(d)
Spatial Representation:	The Barbara Worth Drain, Peach Drain, and Rice Drain only. For the 5 samples: 1 station located off Anderhold Road south of Highway S80 where drain comes alongside road. This information only applies to the Barbara Worth Drain area of the Imperial Valley Drains. For the 2 samples: 1 station located downstream of Meloland Road. This information only applies to the Central Drain area of the Imperial Valley Drains. For the 3 samples: One station located at highway 115 crossing. This information only applies to the Peach Drain area of the Imperial Valley Drains.
Temporal Representation:	Samples were collected on 12-5-1999, 10/22/2002, in 1992, 1995-1996 and 2000-2002.
Environmental Conditions:
QAPP Information:	Toxic Substances Monitoring Program 1992-93 Data Report. Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 1996-2000. Department of Fish and Game. Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 2001-2002. Department of Fish and Game.
QAPP Information Reference(s):

DECISION ID	19121	Region 7
Imperial Valley Drains

Pollutant:	Aldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.5 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. LOE No. 45990 is combined with LOE No. 5573 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria. None of 44 fish tissue samples exceeded the National Academy of Sciences fish tissue guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 19121, Aldrin Region 7      Imperial Valley Drains
LOE ID:	45990
Pollutant:	Aldrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Aldrin. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum Aldrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19121, Aldrin Region 7      Imperial Valley Drains
LOE ID:	5573
Pollutant:	Aldrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the NAS tissue guideline (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 19121, Aldrin Region 7      Imperial Valley Drains
LOE ID:	5059
Pollutant:	Aldrin | Arsenic | Chlordane | Heptachlor | Heptachlor epoxide | alpha-Endosulfan (Endosulfan 1) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: 3 ug/l Aldrin, 0.22 ug/l alpha Endosulfan, 340 ug/l Arsenic, 0.22 ug/l beta-Endosulfan, 2.4 ug/l Chlordane, 0.52 ug/l Heptachlor, and 0.52 ug/l Heptachlor epoxide (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21273	Region 7
Imperial Valley Drains

Pollutant:	Anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE No 5066 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21273, Anthracene Region 7      Imperial Valley Drains
LOE ID:	5066
Pollutant:	Anthracene | Endosulfan sulfate | Endrin aldehyde | Fluorene | alpha-Endosulfan (Endosulfan 1) | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.014 ug/l alpha-BHC, 240 ug/l alpha Endosulfan, 110000 ug/l Anthracene, 0.046 ug/l beta-BHC, 240 ug/l beta-Endosulfan, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin Aldehyde, and14000 ug/l Fluorene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21412	Region 7
Imperial Valley Drains

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1, 3.5, and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria, and none of 12 fish tissue samples exceeded the Office of Environmental Health Hazard Assessment fish tissue guideline. This sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21412, Arsenic Region 7      Imperial Valley Drains
LOE ID:	45991
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Arsenic. Seventeen composites (1 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Seventeen samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for arsenic in fish tissue is 0.0034 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. It is assumed that 10% of the total arsenic is present as inorganic arsenic. This constituent is a carcinogen therefore the risk level is set to one in a million.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21412, Arsenic Region 7      Imperial Valley Drains
LOE ID:	5059
Pollutant:	Aldrin | Arsenic | Chlordane | Heptachlor | Heptachlor epoxide | alpha-Endosulfan (Endosulfan 1) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: 3 ug/l Aldrin, 0.22 ug/l alpha Endosulfan, 340 ug/l Arsenic, 0.22 ug/l beta-Endosulfan, 2.4 ug/l Chlordane, 0.52 ug/l Heptachlor, and 0.52 ug/l Heptachlor epoxide (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21412, Arsenic Region 7      Imperial Valley Drains
LOE ID:	5072
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the USFWS Biological Effects Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	United State Fish and Wildlife Service (USFWS) Biological Effect Criteria of 0.25 mg/l for the protection of aquatic life uses (USDOI, 1998).
Guideline Reference:	Guidelines for Interpretation of the Biological Effect of Selected Constituents in Biota, Water, and Sediment. US Department of Interior report.
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21412, Arsenic Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21412, Arsenic Region 7      Imperial Valley Drains
LOE ID:	5545
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-three fish fillet samples and 24 whole fish samples were taken at 19 locations in Imperial Valley drains. Nineteen fish fillet and 16 whole fish sample results could not be used in this assessment because the consituent was not analyzed in the sample. The 4 fish fillet samples and 8 whole fish samples that were acceptable were generally collected from 8/1990 through 11/2000 at nine locations. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 1 mg/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach drain, Tokay drain, Barbara Worth drain, Warren drain, Dixie drain No.1, Dixie drain No.3, Dixie drain No.5, Forgetmenot drain, and West Side drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1986 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-three fish fillet samples of carp, tilapia, channel catfish, flathead catfish, spiny soft shell turtle, redbelly tilapia, and Mozambique tilapia were collected. Seven carp fillet composite samples were collected in the years 1985, (2)1986, (3)1990 and 1999. Three carp single fish fillet samples were collected in the years 1986, 1989-90. Two tilapia fillet composite samples were collected in the years 1996, and 2000. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. One flathead catfish single fish fillet sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. Three Mozambique tilapia fillet composite samples were collected in year (3)1986. Twenty-four whole fish composite samples of mosquitofish, and sailfin molly were collected. Fifteen mosquitofish whole fish composite samples were collected in the years 1985, (2)1986, 1989, (2)1990, (4)1991, 1995-96, (3)2000. Nine sailfin molly whole fish composite samples were collected in the years (3)1986, (2)1989, 1991, (2)1992, 2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

DECISION ID	21060	Region 7
Imperial Valley Drains

Pollutant:	Benzo(a)anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE Nos. 5108 and 5071 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 3 water samples exceeded the California Toxics Rule criteria. None of 5 sediment samples exceed the sediment quality guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21060, Benzo(a)anthracene Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21060, Benzo(a)anthracene Region 7      Imperial Valley Drains
LOE ID:	5071
Pollutant:	Benzo(a)anthracene | Benzo(a)pyrene (3,4-Benzopyrene -7-d) | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Chrysene (C1-C4) | Dibenz[a,h]anthracene | Indeno[1,2,3-cd]pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three water quality samples were collected and analyzed in October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 ug/l Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, and 0.049 ug/l Indeno(1,2,3-cd) Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three water samples were collected. Water samples were generally collected and analyzed in October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21224	Region 7
Imperial Valley Drains

Pollutant:	Benzo(a)pyrene (3,4-Benzopyrene -7-d)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE Nos. 4963 and 5071 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 3 water samples exceeded the California Toxics Rule criteria. None of 5 sediment samples exceeded the sediment quality guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21224, Benzo(a)pyrene (3,4-Benzopyrene -7-d) Region 7      Imperial Valley Drains
LOE ID:	5071
Pollutant:	Benzo(a)anthracene | Benzo(a)pyrene (3,4-Benzopyrene -7-d) | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Chrysene (C1-C4) | Dibenz[a,h]anthracene | Indeno[1,2,3-cd]pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three water quality samples were collected and analyzed in October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 ug/l Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, and 0.049 ug/l Indeno(1,2,3-cd) Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three water samples were collected. Water samples were generally collected and analyzed in October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21224, Benzo(a)pyrene (3,4-Benzopyrene -7-d) Region 7      Imperial Valley Drains
LOE ID:	4963
Pollutant:	Benzo(a)pyrene (3,4-Benzopyrene -7-d)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were generally collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentration (PEC) of 1450 ug/kg for the protection of freshwater organisms to toxic effects (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected at each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21209	Region 7
Imperial Valley Drains

Pollutant:	Benzo[b]fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE No. 5071 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 3 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21209, Benzo[b]fluoranthene Region 7      Imperial Valley Drains
LOE ID:	5071
Pollutant:	Benzo(a)anthracene | Benzo(a)pyrene (3,4-Benzopyrene -7-d) | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Chrysene (C1-C4) | Dibenz[a,h]anthracene | Indeno[1,2,3-cd]pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three water quality samples were collected and analyzed in October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 ug/l Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, and 0.049 ug/l Indeno(1,2,3-cd) Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three water samples were collected. Water samples were generally collected and analyzed in October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21210	Region 7
Imperial Valley Drains

Pollutant:	Benzo[k]fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE No. 5071 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 3 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21210, Benzo[k]fluoranthene Region 7      Imperial Valley Drains
LOE ID:	5071
Pollutant:	Benzo(a)anthracene | Benzo(a)pyrene (3,4-Benzopyrene -7-d) | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Chrysene (C1-C4) | Dibenz[a,h]anthracene | Indeno[1,2,3-cd]pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three water quality samples were collected and analyzed in October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 ug/l Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, and 0.049 ug/l Indeno(1,2,3-cd) Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three water samples were collected. Water samples were generally collected and analyzed in October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21116	Region 7
Imperial Valley Drains

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1, 3.5 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 water samples exceeded the California Toxics Rule criteria. None of 13 fish tissue samples exceeded the Office of Environmental Health hazard Assessment fish tissue guideline. None of 5 sediment samples exceeded the sediment quality guidelines. This sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21116, Cadmium Region 7      Imperial Valley Drains
LOE ID:	45992
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Cadmium. Seventeen composites (1 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for cadmium in fish tissue is 2.2 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21116, Cadmium Region 7      Imperial Valley Drains
LOE ID:	5546
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	9
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-three fish fillet samples and 24 whole fish samples were taken at 19 locations in Imperial Valley drains. Twenty-two fish fillet and 16 whole fish sample results could not be used in this assessment because the consituent was not analyzed in the sample. The 1 fillet and 8 whole fish samples that were acceptable were generally collected from 8/1990 through 11/2000 at seven locations. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 3 mg/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach drain, Tokay drain, Barbara Worth drain, Warren drain, Dixie drain No.1, Dixie drain No.3, Dixie drain No.5, Forgetmenot drain, and West Side drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1986 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-three fish fillet samples of carp, tilapia, channel catfish, flathead catfish, spiny soft shell turtle, redbelly tilapia, and Mozambique tilapia were collected. Seven carp fillet composite samples were collected in the years 1985, (2)1986, (3)1990 and 1999. Three carp single fish fillet samples were collected in the years 1986, 1989-90. Two tilapia fillet composite samples were collected in the years 1996, and 2000. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. One flathead catfish single fish fillet sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. Three Mozambique tilapia fillet composite samples were collected in year (3)1986. Twenty-four whole fish composite samples of mosquitofish, and sailfin molly were collected. Fifteen mosquitofish whole fish composite samples were collected in the years 1985, (2)1986, 1989, (2)1990, (4)1991, 1995-96, (3)2000. Nine sailfin molly whole fish composite samples were collected in the years (3)1986, (2)1989, 1991, (2)1992, 2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 21116, Cadmium Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21116, Cadmium Region 7      Imperial Valley Drains
LOE ID:	5062
Pollutant:	Cadmium | Lead | Nickel | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were generally collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Hardness Dependent Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: Cadmium, Lead, Nickel, and Zinc (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21127	Region 7
Imperial Valley Drains

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 40 fish tissue samples exceeded the Office of Environmental Health Hazard Assessment fish tissue guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21127, Chlorpyrifos Region 7      Imperial Valley Drains
LOE ID:	5531
Pollutant:	Chlorpyrifos
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 10000 ug/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 21127, Chlorpyrifos Region 7      Imperial Valley Drains
LOE ID:	46002
Pollutant:	Chlorpyrifos
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Chlorpyrifos. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for chlorpyrifos in fish tissue is 660 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21171	Region 7
Imperial Valley Drains

Pollutant:	Chromium (total)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE No. 5108 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under section 3.6 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 sediment samples exceeded the sediment quality guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21171, Chromium (total) Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21062	Region 7
Imperial Valley Drains

Pollutant:	Chrysene (C1-C4)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, use rating of LOE Nos. 5108 and 5071 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 3 water samples exceeded the California Toxics Rule criteria. None of 5 sediment samples exceeded the sediment quality guidelines. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21062, Chrysene (C1-C4) Region 7      Imperial Valley Drains
LOE ID:	5071
Pollutant:	Benzo(a)anthracene | Benzo(a)pyrene (3,4-Benzopyrene -7-d) | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Chrysene (C1-C4) | Dibenz[a,h]anthracene | Indeno[1,2,3-cd]pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three water quality samples were collected and analyzed in October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 ug/l Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, and 0.049 ug/l Indeno(1,2,3-cd) Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three water samples were collected. Water samples were generally collected and analyzed in October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21062, Chrysene (C1-C4) Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21185	Region 7
Imperial Valley Drains

Pollutant:	Copper
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, use ratings are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 water samples exceeded the U.S. Fish and Wildlife Service criteria. None of 6 water samples exceeded the California Toxics Rule criteria. None of 5 sediment samples exceeded the sediment quality guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21185, Copper Region 7      Imperial Valley Drains
LOE ID:	4944
Pollutant:	Copper
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were generally collected and analyzed twice, in May and October of 2002 at 3 Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule Hardness Dependent Criterion Maximum Concentration (CMC) for the protection of freshwater aquatic life uses (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21185, Copper Region 7      Imperial Valley Drains
LOE ID:	5073
Pollutant:	Copper
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the USFWS Biological Effects Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	United State Fish and Wildlife Service (USFWS) Biological Effects Criteria of 15 mg/l for the protection of aquatic life uses (USDOI, 1998).
Guideline Reference:	Guidelines for Interpretation of the Biological Effect of Selected Constituents in Biota, Water, and Sediment. US Department of Interior report.
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21185, Copper Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	22036	Region 7
Imperial Valley Drains

Pollutant:	Diazinon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.5 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Department of Fish and Game criteria. None of 40 fish tissue samples exceeded the Office of Environmental Health Hazard Assessment fish tissue guideline, and none of four fish tissue sample exceeded the modified OEHHA fish tissue guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 22036, Diazinon Region 7      Imperial Valley Drains
LOE ID:	4952
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains. Of these total samples, none exceeded the CDFG Hazardous Assessment Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	California Department of Fish and Game (CDFG) Hazardous Assessment Criteria of 0.16 ug/l for the protection of aquatic life uses (Siepmann and Finlayson, 2000).
Guideline Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	Quality Assurance and Quality Control for the sampling and analysis of this study was conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 22036, Diazinon Region 7      Imperial Valley Drains
LOE ID:	46167
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Diazinon. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for diazinon in fish tissue is 1,500 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 22036, Diazinon Region 7      Imperial Valley Drains
LOE ID:	5532
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the OEHHA Screening Value. (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 300 ug/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

DECISION ID	21061	Region 7
Imperial Valley Drains

Pollutant:	Dibenz[a,h]anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of the LOE No. 5071 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 3 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21061, Dibenz[a,h]anthracene Region 7      Imperial Valley Drains
LOE ID:	5071
Pollutant:	Benzo(a)anthracene | Benzo(a)pyrene (3,4-Benzopyrene -7-d) | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Chrysene (C1-C4) | Dibenz[a,h]anthracene | Indeno[1,2,3-cd]pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three water quality samples were collected and analyzed in October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 ug/l Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, and 0.049 ug/l Indeno(1,2,3-cd) Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three water samples were collected. Water samples were generally collected and analyzed in October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21358	Region 7
Imperial Valley Drains

Pollutant:	Endosulfan sulfate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of the LOE No. 5066 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21358, Endosulfan sulfate Region 7      Imperial Valley Drains
LOE ID:	5066
Pollutant:	Anthracene | Endosulfan sulfate | Endrin aldehyde | Fluorene | alpha-Endosulfan (Endosulfan 1) | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.014 ug/l alpha-BHC, 240 ug/l alpha Endosulfan, 110000 ug/l Anthracene, 0.046 ug/l beta-BHC, 240 ug/l beta-Endosulfan, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin Aldehyde, and14000 ug/l Fluorene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21153	Region 7
Imperial Valley Drains

Pollutant:	Endrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1, 3.5, and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. LOE No. 46197 is combined with LOE No. 5615 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 water samples exceeded the California Toxics Rule criteria. None of 44 fish tissue samples exceeded the NAS fish tissue guidelines. None of 5 sediment samples exceeded the sediment quality guidelines. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21153, Endrin Region 7      Imperial Valley Drains
LOE ID:	5067
Pollutant:	Endrin | Fluoranthene | Nickel | Pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.81 ug/l Endrin, 370 ug/l Fluoranthene, 4600 ug/l Nickel, and 11000 ug/l Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21153, Endrin Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21153, Endrin Region 7      Imperial Valley Drains
LOE ID:	5534
Pollutant:	Endrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 1000 ug/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 21153, Endrin Region 7      Imperial Valley Drains
LOE ID:	5615
Pollutant:	Endrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the NAS tissue guideline (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 21153, Endrin Region 7      Imperial Valley Drains
LOE ID:	46184
Pollutant:	Endrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Endrin. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for endrin in fish tissue is 660 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21153, Endrin Region 7      Imperial Valley Drains
LOE ID:	46197
Pollutant:	Endrin
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Endrin. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum Endrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21152	Region 7
Imperial Valley Drains

Pollutant:	Endrin aldehyde
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of the LOE No. 5066 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21152, Endrin aldehyde Region 7      Imperial Valley Drains
LOE ID:	5066
Pollutant:	Anthracene | Endosulfan sulfate | Endrin aldehyde | Fluorene | alpha-Endosulfan (Endosulfan 1) | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.014 ug/l alpha-BHC, 240 ug/l alpha Endosulfan, 110000 ug/l Anthracene, 0.046 ug/l beta-BHC, 240 ug/l beta-Endosulfan, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin Aldehyde, and14000 ug/l Fluorene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21208	Region 7
Imperial Valley Drains

Pollutant:	Fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, use rating of the LOE Nos. 5067 and 5108 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 water samples exceeded the California Toxics Rule criteria. None of 5 sediment samples exceeded the sediment quality guidelines. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21208, Fluoranthene Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21208, Fluoranthene Region 7      Imperial Valley Drains
LOE ID:	5067
Pollutant:	Endrin | Fluoranthene | Nickel | Pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.81 ug/l Endrin, 370 ug/l Fluoranthene, 4600 ug/l Nickel, and 11000 ug/l Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21154	Region 7
Imperial Valley Drains

Pollutant:	Fluorene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, use rating of the LOE Nos. 5066 and 5108 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria. None of 5 sediment samples exceeded the sediment quality guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21154, Fluorene Region 7      Imperial Valley Drains
LOE ID:	5066
Pollutant:	Anthracene | Endosulfan sulfate | Endrin aldehyde | Fluorene | alpha-Endosulfan (Endosulfan 1) | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.014 ug/l alpha-BHC, 240 ug/l alpha Endosulfan, 110000 ug/l Anthracene, 0.046 ug/l beta-BHC, 240 ug/l beta-Endosulfan, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin Aldehyde, and14000 ug/l Fluorene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21154, Fluorene Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21422	Region 7
Imperial Valley Drains

Pollutant:	Heptachlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.5 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. LOE No. 46200 is combined with LOE No. 5625 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria. None of 44 fish tissue samples exceeded the National Academy of Sciences fish tissue guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21422, Heptachlor Region 7      Imperial Valley Drains
LOE ID:	5059
Pollutant:	Aldrin | Arsenic | Chlordane | Heptachlor | Heptachlor epoxide | alpha-Endosulfan (Endosulfan 1) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: 3 ug/l Aldrin, 0.22 ug/l alpha Endosulfan, 340 ug/l Arsenic, 0.22 ug/l beta-Endosulfan, 2.4 ug/l Chlordane, 0.52 ug/l Heptachlor, and 0.52 ug/l Heptachlor epoxide (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21422, Heptachlor Region 7      Imperial Valley Drains
LOE ID:	46200
Pollutant:	Heptachlor
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Heptachlor. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum Heptachlor concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21422, Heptachlor Region 7      Imperial Valley Drains
LOE ID:	5625
Pollutant:	Heptachlor
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the NAS tissue guideline (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

DECISION ID	21423	Region 7
Imperial Valley Drains

Pollutant:	Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.5 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. LOE No. 46214 is combined with LOE No. 5634 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria. None of 44 fish tissue samples exceeded the National Academy of Sciences fish tissue guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21423, Heptachlor epoxide Region 7      Imperial Valley Drains
LOE ID:	5542
Pollutant:	Heptachlor epoxide
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	9
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. Seventeen fish fillet and 14 whole fish sample results could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentrations. The 4 fish fillet samples and 5 whole fish samples that were acceptable were generally collected from 12/1999 through 11/2000 at five locations. Of these total samples, none OEHHA Screening Value (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 4 ug/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 21423, Heptachlor epoxide Region 7      Imperial Valley Drains
LOE ID:	5059
Pollutant:	Aldrin | Arsenic | Chlordane | Heptachlor | Heptachlor epoxide | alpha-Endosulfan (Endosulfan 1) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: 3 ug/l Aldrin, 0.22 ug/l alpha Endosulfan, 340 ug/l Arsenic, 0.22 ug/l beta-Endosulfan, 2.4 ug/l Chlordane, 0.52 ug/l Heptachlor, and 0.52 ug/l Heptachlor epoxide (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21423, Heptachlor epoxide Region 7      Imperial Valley Drains
LOE ID:	46214
Pollutant:	Heptachlor epoxide
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Heptachlor epoxide. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum Heptachlor Epoxide concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21423, Heptachlor epoxide Region 7      Imperial Valley Drains
LOE ID:	46213
Pollutant:	Heptachlor epoxide
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor epoxide. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Eleven samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for heptachlor epoxide in fish tissue is 0.93 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Public Health Goal for Heptachlor and Heptachlor Epoxide in Drinking Water
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21423, Heptachlor epoxide Region 7      Imperial Valley Drains
LOE ID:	5634
Pollutant:	Heptachlor epoxide
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the NAS tissue guideline (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

DECISION ID	22064	Region 7
Imperial Valley Drains

Pollutant:	Hexachlorobenzene/ HCB
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 40 fish tissue samples exceeded the OEHHA fish tissue guideline, none of four fish tissue samples exceeded the modified OEHHA fish tissue guideline, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 22064, Hexachlorobenzene/ HCB Region 7      Imperial Valley Drains
LOE ID:	5543
Pollutant:	Hexachlorobenzene/ HCB
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 20 ug/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 22064, Hexachlorobenzene/ HCB Region 7      Imperial Valley Drains
LOE ID:	46215
Pollutant:	Hexachlorobenzene/ HCB
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Hexachlorobenzene. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for hexachlorobenzene in fish tissue is 2.8 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21272	Region 7
Imperial Valley Drains

Pollutant:	Indeno[1,2,3-cd]pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of the LOE No. 5071 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 3 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21272, Indeno[1,2,3-cd]pyrene Region 7      Imperial Valley Drains
LOE ID:	5071
Pollutant:	Benzo(a)anthracene | Benzo(a)pyrene (3,4-Benzopyrene -7-d) | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Chrysene (C1-C4) | Dibenz[a,h]anthracene | Indeno[1,2,3-cd]pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three water quality samples were collected and analyzed in October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 ug/l Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, and 0.049 ug/l Indeno(1,2,3-cd) Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three water samples were collected. Water samples were generally collected and analyzed in October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21117	Region 7
Imperial Valley Drains

Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, use rating of the LOE Nos. 5108 and 5062 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 water samples exceeded the California Toxics Rule criteria. None of 5 sediment samples exceeded the sediment quality guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21117, Lead Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21117, Lead Region 7      Imperial Valley Drains
LOE ID:	5062
Pollutant:	Cadmium | Lead | Nickel | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were generally collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Hardness Dependent Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: Cadmium, Lead, Nickel, and Zinc (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21186	Region 7
Imperial Valley Drains

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under sections 3.5 and 3.6 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. LOE No. 46199 is combined with LOE No. 6742 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 sediment samples exceeded the sediment quality guidelines. None of 44 fish tissue samples exceeded National Academy of Sciences fish tissue guidelines, and none of 40 fish tissue samples exceeded the OEHHA fish contaminant goal. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21186, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 7      Imperial Valley Drains
LOE ID:	46198
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for HCH, gamma. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for lindane in fish tissue is 4.6 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21186, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 7      Imperial Valley Drains
LOE ID:	46199
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for HCH, gamma. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science guidelines (NAS 1972) establish a maximum Lindane concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21186, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 7      Imperial Valley Drains
LOE ID:	6742
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the NAS tissue guideline (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 21186, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21186, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 7      Imperial Valley Drains
LOE ID:	5544
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 30 ug/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

DECISION ID	21187	Region 7
Imperial Valley Drains

Pollutant:	Mercury
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under sections 3.5 and 3.6 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 sediment samples exceeded the sediment quality guidelines. None of 15 fish tissue samples exceeded the OEHHA fish tissue guideline, and none of four fish tissue samples exceeded the USEPA 304(a) recommended water quality criterion for concentrations of methylmercury in fish tissue of trophic level 4 fish. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21187, Mercury Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21187, Mercury Region 7      Imperial Valley Drains
LOE ID:	5565
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-three fish fillet samples and 24 whole fish samples were taken at 19 locations in Imperial Valley drains. Sixteen fish fillet and 16 whole fish sample results could not be used in this assessment because the consituent was not analyzed in the sample. The 7 fish fillet sample and 8 whole fish samples that were acceptable were generally collected from 8/1990 through 11/2000 at nine locations. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 0.3 mg/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach drain, Tokay drain, Barbara Worth drain, Warren drain, Dixie drain No.1, Dixie drain No.3, Dixie drain No.5, Forgetmenot drain, and West Side drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1986 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-three fish fillet samples of carp, tilapia, channel catfish, flathead catfish, spiny soft shell turtle, redbelly tilapia, and Mozambique tilapia were collected. Seven carp fillet composite samples were collected in the years 1985, (2)1986, (3)1990 and 1999. Three carp single fish fillet samples were collected in the years 1986, 1989-90. Two tilapia fillet composite samples were collected in the years 1996, and 2000. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. One flathead catfish single fish fillet sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. Three Mozambique tilapia fillet composite samples were collected in year (3)1986. Twenty-four whole fish composite samples of mosquitofish, and sailfin molly were collected. Fifteen mosquitofish whole fish composite samples were collected in the years 1985, (2)1986, 1989, (2)1990, (4)1991, 1995-96, (3)2000. Nine sailfin molly whole fish composite samples were collected in the years (3)1986, (2)1989, 1991, (2)1992, 2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 21187, Mercury Region 7      Imperial Valley Drains
LOE ID:	46228
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Mercury. A total of 12 composite were used in this assessment. Four composites were generated from two species for Central Drain: common carp (2 fish per composite) and channel catfish (3 fish per composite). Five composites were generated from two species for Greeson Drain: channel catfish (2-3 fish per composite) and Tilapia spp. (1 fish per composite). Five composites could not be used in the assessment due to a total fish length that did not fall within lengths noted in the guideline. Composites comprised of 1 fish per composite. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The USEPA 304(a) recommended water quality criterion for concentrations of methylmercury in fish tissue of trophic level 4 fish (150 - 500 mm; fillet wet weight) is 0.20 mg/kg.
Guideline Reference:	Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	30766	Region 7
Imperial Valley Drains

Pollutant:	Mirex
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Eleven samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy. This sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 30766, Mirex Region 7      Imperial Valley Drains
LOE ID:	46229
Pollutant:	Mirex
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Mirex. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Eleven samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The modified OEHHA Fish Contaminant Goal for mirex in fish tissue is 0.28 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
	Expedited Cancer Potency Values and Proposed Regulatory Levels for Certain Proposition 65 Carcinogens.
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	22026	Region 7
Imperial Valley Drains

Pollutant:	Naphthalene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of the LOE No. 5108 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under section 3.6 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 sediment samples exceeded the sediment quality guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 22026, Naphthalene Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21118	Region 7
Imperial Valley Drains

Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, use rating of the LOE Nos. 5108, 5062, and 5067 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 water samples exceeded the California Toxics Rule criteria protecting either aquatic life uses, or human health when consuming organisms from this water. None of 5 sediment samples exceeded the sediment quality guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21118, Nickel Region 7      Imperial Valley Drains
LOE ID:	5062
Pollutant:	Cadmium | Lead | Nickel | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were generally collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Hardness Dependent Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: Cadmium, Lead, Nickel, and Zinc (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21118, Nickel Region 7      Imperial Valley Drains
LOE ID:	5067
Pollutant:	Endrin | Fluoranthene | Nickel | Pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.81 ug/l Endrin, 370 ug/l Fluoranthene, 4600 ug/l Nickel, and 11000 ug/l Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21118, Nickel Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	22035	Region 7
Imperial Valley Drains

Pollutant:	Phenanthrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of the LOE No. 5108 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under section 3.6 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 sediment samples exceeded the sediment quality guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 22035, Phenanthrene Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21211	Region 7
Imperial Valley Drains

Pollutant:	Pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, use rating of the LOE Nos. 5108 and 5067 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 water samples exceeded the California Toxics Rule criteria. None of 5 sediment samples exceeded the sediment quality guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21211, Pyrene Region 7      Imperial Valley Drains
LOE ID:	5108
Pollutant:	Arsenic | Benzo(a)anthracene | Cadmium | Chromium (total) | Chrysene (C1-C4) | Copper | Dieldrin | Endrin | Fluoranthene | Fluorene | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Naphthalene | Nickel | PCBs (Polychlorinated biphenyls) | Phenanthrene | Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21211, Pyrene Region 7      Imperial Valley Drains
LOE ID:	5067
Pollutant:	Endrin | Fluoranthene | Nickel | Pyrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.81 ug/l Endrin, 370 ug/l Fluoranthene, 4600 ug/l Nickel, and 11000 ug/l Pyrene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21912	Region 7
Imperial Valley Drains

Pollutant:	Silver
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of the LOE No. 5063 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21912, Silver Region 7      Imperial Valley Drains
LOE ID:	5063
Pollutant:	Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Hardness Dependent Criterion Maximum Concentrations (CMC) for the protection of freshwater aquatic life (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21119	Region 7
Imperial Valley Drains

Pollutant:	Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, use rating of the LOE Nos. 5062 and 4969 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 5 water samples exceeded the California Toxics Rule criteria. None of 5 sediment samples exceeded the sediment quality guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21119, Zinc Region 7      Imperial Valley Drains
LOE ID:	4969
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were generally collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Consensus Based Sediment Quality Guideline Probable Effects Concentration (PEC) of 459 mg/kg for the protection of freshwater organisms to toxic effects (Macdonald et al, 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were generally collected and analyzed twice, in May and October of 2002.Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21119, Zinc Region 7      Imperial Valley Drains
LOE ID:	5062
Pollutant:	Cadmium | Lead | Nickel | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were generally collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Hardness Dependent Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: Cadmium, Lead, Nickel, and Zinc (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21356	Region 7
Imperial Valley Drains

Pollutant:	alpha-Endosulfan (Endosulfan 1)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE Nos. 5059 and 5066 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 samples exceeded the California Toxics Rule criteria protecting either aquatic life uses, or human health when consuming organisms from this water. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21356, alpha-Endosulfan (Endosulfan 1) Region 7      Imperial Valley Drains
LOE ID:	5066
Pollutant:	Anthracene | Endosulfan sulfate | Endrin aldehyde | Fluorene | alpha-Endosulfan (Endosulfan 1) | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.014 ug/l alpha-BHC, 240 ug/l alpha Endosulfan, 110000 ug/l Anthracene, 0.046 ug/l beta-BHC, 240 ug/l beta-Endosulfan, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin Aldehyde, and14000 ug/l Fluorene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21356, alpha-Endosulfan (Endosulfan 1) Region 7      Imperial Valley Drains
LOE ID:	5059
Pollutant:	Aldrin | Arsenic | Chlordane | Heptachlor | Heptachlor epoxide | alpha-Endosulfan (Endosulfan 1) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: 3 ug/l Aldrin, 0.22 ug/l alpha Endosulfan, 340 ug/l Arsenic, 0.22 ug/l beta-Endosulfan, 2.4 ug/l Chlordane, 0.52 ug/l Heptachlor, and 0.52 ug/l Heptachlor epoxide (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21137	Region 7
Imperial Valley Drains

Pollutant:	alpha.-BHC (Benzenehexachloride or alpha-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE No 5066 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21137, alpha.-BHC (Benzenehexachloride or alpha-HCH) Region 7      Imperial Valley Drains
LOE ID:	5066
Pollutant:	Anthracene | Endosulfan sulfate | Endrin aldehyde | Fluorene | alpha-Endosulfan (Endosulfan 1) | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.014 ug/l alpha-BHC, 240 ug/l alpha Endosulfan, 110000 ug/l Anthracene, 0.046 ug/l beta-BHC, 240 ug/l beta-Endosulfan, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin Aldehyde, and14000 ug/l Fluorene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21138	Region 7
Imperial Valley Drains

Pollutant:	beta-BHC (Benzenehexachloride or beta-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE No. 5066 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21138, beta-BHC (Benzenehexachloride or beta-HCH) Region 7      Imperial Valley Drains
LOE ID:	5066
Pollutant:	Anthracene | Endosulfan sulfate | Endrin aldehyde | Fluorene | alpha-Endosulfan (Endosulfan 1) | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.014 ug/l alpha-BHC, 240 ug/l alpha Endosulfan, 110000 ug/l Anthracene, 0.046 ug/l beta-BHC, 240 ug/l beta-Endosulfan, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin Aldehyde, and14000 ug/l Fluorene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21357	Region 7
Imperial Valley Drains

Pollutant:	beta-Endosulfan (Endosulfan 2)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of LOE Nos. 5066 and 5059 are changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the California Toxics Rule criteria protecting either aquatic life uses, or human health when consuming organisms from this water. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21357, beta-Endosulfan (Endosulfan 2) Region 7      Imperial Valley Drains
LOE ID:	5066
Pollutant:	Anthracene | Endosulfan sulfate | Endrin aldehyde | Fluorene | alpha-Endosulfan (Endosulfan 1) | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming organisms from aquatic systems were used for the following constituents: 0.014 ug/l alpha-BHC, 240 ug/l alpha Endosulfan, 110000 ug/l Anthracene, 0.046 ug/l beta-BHC, 240 ug/l beta-Endosulfan, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin Aldehyde, and14000 ug/l Fluorene (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21357, beta-Endosulfan (Endosulfan 2) Region 7      Imperial Valley Drains
LOE ID:	5059
Pollutant:	Aldrin | Arsenic | Chlordane | Heptachlor | Heptachlor epoxide | alpha-Endosulfan (Endosulfan 1) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: 3 ug/l Aldrin, 0.22 ug/l alpha Endosulfan, 340 ug/l Arsenic, 0.22 ug/l beta-Endosulfan, 2.4 ug/l Chlordane, 0.52 ug/l Heptachlor, and 0.52 ug/l Heptachlor epoxide (USEPA, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	22065	Region 7
Imperial Valley Drains

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. However, a use rating of the LOE No. 5118 is changed from fully supporting to insufficient due to insufficient sample size required by the Listing Policy to determine if the water quality objectives are met. No new data were assessed in current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 6 water samples exceeded the Basin Plan water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 22065, pH Region 7      Imperial Valley Drains
LOE ID:	5118
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality measurements were collected and analyzed twice in 2002 at 3 locations in Imperial Valley drains. Of these total measurements, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: Since the regional waters are somewhat alkaline, pH shall range from 6.0-9.0 (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Measurements were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six measurements were collected. Measurements were generally collected and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	18300	Region 7
Imperial Valley Drains

Pollutant:	Selenium
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2010)
Revision Status	Original
Sources:	Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4.1, 4.5, and 4.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess pollutant. LOE No. 46244 is combined with LOE No. 5443 for a use rating determination because both of them were assessed for the same beneficial uses, in the same matrix, and the same water quality objectives. Three of samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Three of six water samples exceeded the Basin Plan Objective and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 18300, Selenium Region 7      Imperial Valley Drains
LOE ID:	4957
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains. Of these total samples, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: For all surface waters that are tributaries to the Salton Sea, a one hour average value of selenium shall not exceed .02 mg/L (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed from all sites twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 18300, Selenium Region 7      Imperial Valley Drains
LOE ID:	5443
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	47
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-three fish fillet samples and 24 whole fish samples were taken at 19 locations in Imperial Valley drains. The samples were generally collected from 10/1986 through 11/2000. Of these total samples, none exceeded the OEHHA Fish Contaminant Goal (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 7400 ppb to protect human health when consuming fish (OEHHA, 2008).
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach drain, Tokay drain, Barbara Worth drain, Warren drain, Dixie drain No.1, Dixie drain No.3, Dixie drain No.5, Forgetmenot drain, and West Side drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1986 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-three fish fillet samples of carp, tilapia, channel catfish, flathead catfish, spiny soft shell turtle, redbelly tilapia, and Mozambique tilapia were collected. Seven carp fillet composite samples were collected in the years 1985, (2)1986, (3)1990 and 1999. Three carp single fish fillet samples were collected in the years 1986, 1989-90. Two tilapia fillet composite samples were collected in the years 1996, and 2000. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. One flathead catfish single fish fillet sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. Three Mozambique tilapia fillet composite samples were collected in year (3)1986. Twenty-four whole fish composite samples of mosquitofish, and sailfin molly were collected. Fifteen mosquitofish whole fish composite samples were collected in the years 1985, (2)1986, 1989, (2)1990, (4)1991, 1995-96, (3)2000. Nine sailfin molly whole fish composite samples were collected in the years (3)1986, (2)1989, 1991, (2)1992, 2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.
Line of Evidence (LOE) for Decision ID 18300, Selenium Region 7      Imperial Valley Drains
LOE ID:	25814
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	6
Number of Exceedances:	3
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains. Of these total samples, three exceeded the Basin Plan Objective. The exceedances were found in samples collected on 5/08/2002, 5/09/2002, and 5/13/2002 at the three locations (SWAMP, 2007).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: For all surface waters that are tributaries to the Salton Sea, a four day average value of selenium shall not exceed .005 mg/L (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed from all sites twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 18300, Selenium Region 7      Imperial Valley Drains
LOE ID:	46244
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Fish fillet
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Selenium. Seventeen composites (1 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.
Data Reference:	RWB7 Fish Tissue Study 2004
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Colorado River Basin).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	The OEHHA Fish Contaminant Goal for selenium in fish tissue is 7.4 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A background dietary consumption rate of 0.114 mg/day is applied for this micronutrient.
Guideline Reference:	Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation:	Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]
Temporal Representation:	Data was collected over the time period 11/2/2004-11/4/2004.
Environmental Conditions:	Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information:	The SWAMP QAPP (2002) was followed.
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 18300, Selenium Region 7      Imperial Valley Drains
LOE ID:	30274
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guideline for the sediment fraction of Selenium for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	20669	Region 7
Imperial Valley Drains

Pollutant:	Sedimentation/Siltation
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2010)
Revision Status	Original
Sources:	Agricultural Return Flows
TMDL Name:	Imperial Valley Drains (Niland 2, P, Pumice, and their tributary drains) Sediment TMDL
TMDL Project Code:	14
Date TMDL Approved by USEPA:	09/30/2005
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Line of Evidence No 2962 is a placeholder line of evidence, containing no data it is used to indicate this was a listing made prior to 2006. Based on the applicable factor, the Imperial Valley Drains sedimentation/siltation TMDL was approved by USEPA on September 30, 2005. The approved TMDL and implementation plan is expected to result in attainment of the standard. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 20669, Sedimentation/Siltation Region 7      Imperial Valley Drains
LOE ID:	2962
Pollutant:	Sedimentation/Siltation
LOE Subgroup:	Pollutant-Water
Matrix:	Not Specified
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:
Number of Exceedances:
Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference:	Placeholder reference 2006 303(d)
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:
Objective/Criterion Reference:
Evaluation Guideline:
Guideline Reference:
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information:	QA Info Missing
QAPP Information Reference(s):

DECISION ID	29583	Region 7
Imperial Valley Drains

Pollutant:	1-Methylnaphthalene | 2,3,5-Trimethylnaphthalene | 2,6-Dimethylnaphthalene | 2-Methylnaphthalene | Acenaphthylene | Naphthalene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, and 2,3,5-Trimethylnaphthalene consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved fractions of Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene or the sediment fractions of Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene or the sediment fractions of Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29583, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29871
Pollutant:	1-Methylnaphthalene | 2,3,5-Trimethylnaphthalene | 2,6-Dimethylnaphthalene | 2-Methylnaphthalene | Acenaphthylene | Naphthalene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29583, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30053
Pollutant:	1-Methylnaphthalene | 2,3,5-Trimethylnaphthalene | 2,6-Dimethylnaphthalene | 2-Methylnaphthalene | Acenaphthylene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29596	Region 7
Imperial Valley Drains

Pollutant:	1-Methylphenanthrene | Phenanthrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess Phenanthrene, and 1-Methylphenanthrene consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved fractions of Phenanthrene, or 1-Methylphenanthrene or the sediment fraction of 1-Methylphenanthrene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Phenanthrene, or 1-Methylphenanthrene or the sediment fraction of 1-Methylphenanthrene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29596, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29870
Pollutant:	1-Methylphenanthrene | Phenanthrene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Phenanthrene, or 1-Methylphenanthrene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29596, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30052
Pollutant:	1-Methylphenanthrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guideline for the sediment fraction of 1-Methylphenanthrene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29636	Region 7
Imperial Valley Drains

Pollutant:	Acenaphthene | Dichlorobenzophenone | Indeno[1,2,3-cd]pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Acenaphthene, pp-DCBP, and Indeno(1,2,3,c,d)Pyrene consistent with Listing Policy section 3.6. No evaluation guidelines for the sediment fractions of Acenaphthene, pp-DCBP, or Indeno(1,2,3,c,d)Pyrene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the sediment fractions of Acenaphthene, pp-DCBP, or Indeno(1,2,3,c,d)Pyrene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29636, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30075
Pollutant:	Acenaphthene | Dichlorobenzophenone | Indeno[1,2,3-cd]pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Acenaphthene, pp-DCBP, or Indeno(1,2,3,c,d)Pyrene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29627	Region 7
Imperial Valley Drains

Pollutant:	Aldrin | Chlorpyrifos | Diazinon | Toxaphene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Aldrin, Chlorpyrifos, Diazinon, and Toxaphene consistent with Listing Policy section 3.6. No evaluation guidelines for the sediment fractions of Aldrin, Chlorpyrifos, Diazinon, or Toxaphene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the sediment fractions of Aldrin, Chlorpyrifos, Diazinon, or Toxaphene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29627, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30074
Pollutant:	Aldrin | Chlorpyrifos | Diazinon | Toxaphene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Aldrin, Chlorpyrifos, Diazinon, or Toxaphene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29625	Region 7
Imperial Valley Drains

Pollutant:	Aluminum | Manganese | Silver
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Aluminum, Manganese, and Silver consistent with Listing Policy section 3.6. No evaluation guidelines for the sediment fractions of Aluminum, Manganese, or Silver for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the sediment fractions of Aluminum, Manganese, or Silver for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29625, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30071
Pollutant:	Aluminum | Manganese | Silver
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Aluminum, Manganese, or Silver for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29592	Region 7
Imperial Valley Drains

Pollutant:	Ametryn | Prometryn | Simetryn | Terbutryn
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Ametryn, Prometryn, Simetryn, and Terbutryn consistent with Listing Policy section 3.1. No evaluation guidelines for the dissolved fractions of Ametryn, Prometryn, Simetryn, or Terbutryn for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Ametryn, Prometryn, Simetryn, or Terbutryn for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29592, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29882
Pollutant:	Ametryn | Prometryn | Simetryn | Terbutryn
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Ametryn, Prometryn, Simetryn, or Terbutryn for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29609	Region 7
Imperial Valley Drains

Pollutant:	Anthracene | Benzo(a)anthracene | Dibenz[a,h]anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Anthracene, Benz(a)Anthracene, and Dibenzo(a,h)Anthracene consistent with Listing Policy section 3.6. No evaluation guidelines for the sediment fractions of Anthracene, Benz(a)Anthracene, or Dibenzo(a,h)Anthracene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the sediment fractions of Anthracene, Benz(a)Anthracene, or Dibenzo(a,h)Anthracene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29609, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30062
Pollutant:	Anthracene | Benzo(a)anthracene | Dibenz[a,h]anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Anthracene, Benz(a)Anthracene, or Dibenzo(a,h)Anthracene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	30081	Region 7
Imperial Valley Drains

Pollutant:	Atroton | Prometon (Prometone) | Secbumeton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Atroton, Prometon, and Secbumeton consistent with Listing Policy section 3.1. No evaluation guidelines for the dissolved fractions of Atroton, Prometon, or Secbumeton for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Atroton, Prometon, or Secbumeton for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 30081, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29885
Pollutant:	Atroton | Prometon (Prometone) | Secbumeton
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Atroton, Prometon, or Secbumeton for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29376	Region 7
Imperial Valley Drains

Pollutant:	Azinphos, Ethyl (Ethyl Guthion) | Azinphos-methyl (Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Azinphos, methyl, and Azinphos, ethyl consistent with Listing Policy section 3.1. No evaluation guidelines for the dissolved fractions of Azinphos, methyl, or Azinphos, ethyl for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Azinphos, methyl, or Azinphos, ethyl for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29376, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29874
Pollutant:	Azinphos, Ethyl (Ethyl Guthion) | Azinphos-methyl (Guthion)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Azinphos, methyl, or Azinphos, ethyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29598	Region 7
Imperial Valley Drains

Pollutant:	Benzo(e)Pyrene (4,5-benzopyrene) | Benzo[g,h,i]perylene | Biphenyl | Terbufos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess Benzo(g,h,i)Perylene, Benzo(e)Pyrene, Biphenyl, and Terbufos consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, Biphenyl, or Terbufos or the sediment fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, or Biphenyl for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, Biphenyl, or Terbufos or the sediment fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, or Biphenyl for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29598, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29881
Pollutant:	Benzo(e)Pyrene (4,5-benzopyrene) | Benzo[g,h,i]perylene | Biphenyl | Terbufos
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, Biphenyl, or Terbufos for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29598, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30059
Pollutant:	Benzo(e)Pyrene (4,5-benzopyrene) | Benzo[g,h,i]perylene | Biphenyl
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, or Biphenyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	28841	Region 7
Imperial Valley Drains

Pollutant:	Benzo[b]fluoranthene | Benzo[k]fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Benzo(b)Fluoranthene, and Benzo(k)Fluoranthene consistent with Listing Policy section 3.6. No evaluation guidelines for the sediment fractions of Benzo(b)Fluoranthene, or Benzo(k)Fluoranthene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the sediment fractions of Benzo(b)Fluoranthene, or Benzo(k)Fluoranthene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 28841, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30068
Pollutant:	Benzo[b]fluoranthene | Benzo[k]fluoranthene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Benzo(b)Fluoranthene, or Benzo(k)Fluoranthene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29388	Region 7
Imperial Valley Drains

Pollutant:	Bolstar | Chlordane | Ciodrin | Dacthal | Demeton s | Dichlorvos | Dimethoate | Disulfoton | Endrin Ketone | Ethoprop | Famphur | Mirex | Naled | Oxadiazon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess Chlordane, Bolstar, Ciodrin, Dacthal, Demeton s, Dichlorvos, Dimethoate, Disulfoton, Endrin Ketone, Ethoprop, Famphur, Mirex, Naled, and Oxadiazon consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved fractions of Chlordane, Bolstar, Ciodrin, Dacthal, Demeton s, Dichlorvos, Dimethoate, Disulfoton, Endrin Ketone, Ethoprop, Famphur, Mirex, Naled, or Oxadiazon or the sediment fractions of Dacthal, Mirex, or Oxadiazon for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Chlordane, Bolstar, Ciodrin, Dacthal, Demeton s, Dichlorvos, Dimethoate, Disulfoton, Endrin Ketone, Ethoprop, Famphur, Mirex, Naled, or Oxadiazon or the sediment fractions of Dacthal, Mirex, or Oxadiazon for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29388, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29878
Pollutant:	Bolstar | Chlordane | Ciodrin | Dacthal | Demeton s | Dichlorvos | Dimethoate | Disulfoton | Endrin Ketone | Ethoprop | Famphur | Mirex | Naled | Oxadiazon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Chlordane, Bolstar, Ciodrin, Dacthal, Demeton s, Dichlorvos, Dimethoate, Disulfoton, Endrin Ketone, Ethoprop, Famphur, Mirex, Naled, or Oxodiazon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29388, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30057
Pollutant:	Dacthal | Mirex | Oxadiazon
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Dacthal, Mirex, or Oxadiazon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29615	Region 7
Imperial Valley Drains

Pollutant:	Carbon (organic)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess organic Carbon consistent with Listing Policy section 3.6. No evaluation guideline for the sediment fraction of organic Carbon for the protection of human, animal or aquatic life in fresh waters could be found that meets the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guideline for the sediment fraction of organic Carbon for the protection of human, animal or aquatic life in fresh waters could be found that meets the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29615, Carbon (organic) Region 7      Imperial Valley Drains
LOE ID:	30076
Pollutant:	Carbon (organic)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guideline for the sediment fraction of Organic Carbon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29590	Region 7
Imperial Valley Drains

Pollutant:	Carbophenothion | Dichlofenthion | Dioxathion | Ethion | Fenitrothion | Fensulfothion | Fenthion | Malathion | Methidathion | Methyl Parathion | Parathion | Tokuthion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, and Tokuthion consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion or the sediment fractions of Parathion, or Methyl Parathion for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion or the sediment fractions of Parathion, or Methyl Parathion for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29590, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29872
Pollutant:	Carbophenothion | Dichlofenthion | Dioxathion | Ethion | Fenitrothion | Fensulfothion | Fenthion | Malathion | Methidathion | Methyl Parathion | Parathion | Tokuthion
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29590, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30054
Pollutant:	Methyl Parathion | Parathion
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Ethyl Parathion, or Methyl Parathion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29377	Region 7
Imperial Valley Drains

Pollutant:	Chlorfenvinphos | Chlorpyrifos, methyl | Cuomaphos | Dicrotophos | Dyfonate (Fonofos or Fonophos) | Fenchlorphos | Leptophos | Merphos | Mevinphos | Tetrachlorvinphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Sources:	Source Unknown
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, and Chlorpyrifos Methyl consistent with Listing Policy section 3.1. No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29377, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29876
Pollutant:	Chlorfenvinphos | Chlorpyrifos, methyl | Cuomaphos | Dicrotophos | Dyfonate (Fonofos or Fonophos) | Fenchlorphos | Leptophos | Merphos | Mevinphos | Tetrachlorvinphos
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29604	Region 7
Imperial Valley Drains

Pollutant:	Dibenzothiophene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess Dibenzothiophene consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved or sediment fractions of Dibenzothiophene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved or sediment fractions of Dibenzothiophene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29604, Dibenzothiophene Region 7      Imperial Valley Drains
LOE ID:	29889
Pollutant:	Dibenzothiophene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three water quality samples were collected and analyzed in October of 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guideline for the dissolved fraction of Dibenzothiophene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three water samples were collected. Water samples were collected from all three sampling locations and analyzed in October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29604, Dibenzothiophene Region 7      Imperial Valley Drains
LOE ID:	30061
Pollutant:	Dibenzothiophene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guideline for the sediment fraction of Total Petroleum Hydrocarbons as Diesel, used to refer to the dissolved fractions of Diesel Range Organics (dro), for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29610	Region 7
Imperial Valley Drains

Pollutant:	Endosulfan sulfate | alpha-Endosulfan (Endosulfan 1) | beta-Endosulfan (Endosulfan 2)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Endosulfan 1, Endosulfan 2, and Endosulfan Sulfate consistent with Listing Policy section 3.6. No evaluation guidelines for the sediment fractions of Endosulfan 1, Endosulfan 2, or Endosulfan Sulfate for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of sediment fractions of Endosulfan 1, Endosulfan 2, or Endosulfan Sulfate for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29610, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30069
Pollutant:	Endosulfan sulfate | alpha-Endosulfan (Endosulfan 1) | beta-Endosulfan (Endosulfan 2)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Endosulfan 1, Endosulfan 2, or Endosulfan Sulfate for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	22063	Region 7
Imperial Valley Drains

Pollutant:	Ethion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 40 fish tissue samples exceeded the Office of Environmental Health Hazard Assessment fish tissue guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 22063, Ethion Region 7      Imperial Valley Drains
LOE ID:	5541
Pollutant:	Ethion
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 2000 ug/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference:	Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

DECISION ID	29624	Region 7
Imperial Valley Drains

Pollutant:	Heptachlor | Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Heptachlor, and Heptachlor Epoxide consistent with Listing Policy section 3.6. No evaluation guidelines for the sediment fractions of Heptachlor, or Heptachlor Epoxide for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the sediment fractions of Heptachlor, or Heptachlor Epoxide for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29624, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30070
Pollutant:	Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Heptachlor, or Heptachlor Epoxide for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29626	Region 7
Imperial Valley Drains

Pollutant:	Hexachlorobenzene/ HCB | Methoxychlor | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess alpha-HCH, beta-HCH, Hexachlorobenzene, and Methoxychlor consistent with Listing Policy section 3.6. No evaluation guidelines for the sediment fractions of alpha-HCH, beta-HCH, Hexachlorobenzene, or Methoxychlor for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the sediment fractions of alpha-HCH, beta-HCH, Hexachlorobenzene, or Methoxychlor for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29626, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30073
Pollutant:	Hexachlorobenzene/ HCB | Methoxychlor | alpha.-BHC (Benzenehexachloride or alpha-HCH) | beta-BHC (Benzenehexachloride or beta-HCH)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of alpha-HCH, beta-HCH, Hexachlorobenzene, or Methoxychlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	21188	Region 7
Imperial Valley Drains

Pollutant:	Hexachlorocyclohexane (HCH) (mixture)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 40 fish tissue samples exceeded the National Academy of Sciences fish tissue guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 21188, Hexachlorocyclohexane (HCH) (mixture) Region 7      Imperial Valley Drains
LOE ID:	6734
Pollutant:	Hexachlorocyclohexane (HCH) (mixture)
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	40
Number of Exceedances:	0
Data and Information Type:	Fish tissue analysis
Data Used to Assess Water Quality:	Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the NAS tissue guideline (TSMP, 2007).
Data Reference:	Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:	National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).
Guideline Reference:	National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
Spatial Representation:	Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.
Temporal Representation:	Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.
Environmental Conditions:
QAPP Information:	The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).
QAPP Information Reference(s):	Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

DECISION ID	29608	Region 7
Imperial Valley Drains

Pollutant:	Hydroxide | Pheophytin a
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.7.1 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Hydroxide, and Pheophytin a consistent with Listing Policy sections 3.1 and 3.7.1. No evaluation guidelines for the dissolved fractions of Hydroxide, or Pheophytin a for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Hydroxide, or Pheophytin a for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29608, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29890
Pollutant:	Hydroxide | Pheophytin a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three water quality samples were collected and analyzed in October of 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for Hydroxide, or Pheophytin a for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three water samples were collected. Water samples were collected from all three sampling locations and analyzed in May of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29597	Region 7
Imperial Valley Drains

Pollutant:	Oxychlordane | Perylene (Dibenz(de,kl)anthracene) | Phorate | Phosmet | Phosphamidon | Sulfotep | Tedion | Thionazin | Trichlorfon | Trichloronate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, and Trichlorfon consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, Trichlorfon or the sediment fractions of Oxychlordane, Perylene, or Tedion for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, Trichlorfon or the sediment fractions of Oxychlordane, Perylene, or Tedion for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29597, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30058
Pollutant:	Oxychlordane | Perylene (Dibenz(de,kl)anthracene) | Tedion
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of Oxychlordane, Perylene, or Tedion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29597, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29880
Pollutant:	Oxychlordane | Perylene (Dibenz(de,kl)anthracene) | Phorate | Phosmet | Phosphamidon | Sulfotep | Tedion | Thionazin | Trichlorfon | Trichloronate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29602	Region 7
Imperial Valley Drains

Pollutant:	Propazine | Terbuthylazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess Propazine, and Terbuthylazine consistent with Listing Policy section 3.1. No evaluation guidelines for the dissolved fractions of Propazine, or Terbuthylazine for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of Propazine, or Terbuthylazine for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29602, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29887
Pollutant:	Propazine | Terbuthylazine
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of Propazine, or Terbuthylazine for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29603	Region 7
Imperial Valley Drains

Pollutant:	Total Petroleum Hydrocarbons as Diesel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess Total Petroleum Hydrocarbons as Diesel consistent with Listing Policy sections 3.1 and 3.6. Total Petroleum Hydrocarbons as Diesel is used to refer to the dissolved fractions of Diesel Range Organics. No evaluation guidelines for the dissolved or sediment fractions of Total Petroleum Hydrocarbons as Diesel for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved or sediment fractions of Total Petroleum Hydrocarbons as Diesel for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29603, Total Petroleum Hydrocarbons as Diesel Region 7      Imperial Valley Drains
LOE ID:	29888
Pollutant:	Total Petroleum Hydrocarbons as Diesel
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guideline for dissolved fractions of Total Petroleum Hydrocarbons as Diesel, used to refer to the dissolved fractions of Diesel Range Organics (dro), for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five water samples were collected. Water samples were collected and analyzed at W Drain and Trifolium Drain TD1 sampling locations in May of 2002. Water samples were generally collected from all three sampling locations and analyzed in October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29603, Total Petroleum Hydrocarbons as Diesel Region 7      Imperial Valley Drains
LOE ID:	30060
Pollutant:	Total Petroleum Hydrocarbons as Diesel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Four sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guideline for the sediment fraction of Total Petroleum Hydrocarbons as Diesel, used to refer to the dissolved fractions of Diesel Range Organics (dro), for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Four sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 a sediment sample was collected and analyzed from and Trifolium TD1 sampling location only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29591	Region 7
Imperial Valley Drains

Pollutant:	alpha-Chlordene | gama-Chlordene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess alpha-Chlordene, and gamma-Chlordene consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved or sediment fractions of alpha-Chlordene, or gamma-Chlordene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved or sediment fractions of alpha-Chlordene, or gamma-Chlordene for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29591, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29873
Pollutant:	alpha-Chlordene | gama-Chlordene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of alpha-Chlordene, or gamma-Chlordene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29591, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30055
Pollutant:	alpha-Chlordene | gama-Chlordene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of alpha-Chlordene, or gamma-Chlordene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29984	Region 7
Imperial Valley Drains

Pollutant:	cis-Nonachlor | trans-Nonachlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess cis-Nonachlor, and trans-Nonachlor consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved or sediment fractions of cis-Nonachlor, or trans-Nonachlor for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved or sediment fractions of cis-Nonachlor, or trans-Nonachlor for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29984, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	30051
Pollutant:	cis-Nonachlor | trans-Nonachlor
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guidelines for the sediment fractions of cis-Nonachlor, or trans-Nonachlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29984, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29869
Pollutant:	cis-Nonachlor | trans-Nonachlor
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of cis-Nonachlor, or trans-Nonachlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29983	Region 7
Imperial Valley Drains

Pollutant:	delta-BHC (Benzenehexachloride or delta-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess delta-BHC consistent with Listing Policy sections 3.1 and 3.6. No evaluation guidelines for the dissolved or sediment fractions of delta-BHC for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved or sediment fractions of delta-BHC for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29983, delta-BHC (Benzenehexachloride or delta-HCH) Region 7      Imperial Valley Drains
LOE ID:	30050
Pollutant:	delta-BHC (Benzenehexachloride or delta-HCH)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Three sediment quality samples were collected and analyzed in May of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006). No evaluation guideline for the sediment fraction of delta-BHC for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Three sediment samples were collected. Sediment samples were collected and analyzed in May of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 29983, delta-BHC (Benzenehexachloride or delta-HCH) Region 7      Imperial Valley Drains
LOE ID:	29868
Pollutant:	delta-BHC (Benzenehexachloride or delta-HCH)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guideline for the dissolved fraction of delta-BHC for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	29378	Region 7
Imperial Valley Drains

Pollutant:	o,p'-DDD (Dichlorodiphenyldichloroethane)) | o,p'-DDE (Dichlorodiphenyldichloroethylene) | o,p'-DDT (Dichlorodiphenyltrichloroethane) | p,p'-DDMU
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess o,p'-DDD, o,p'-DDE, o,p'-DDT, and p,p'-DDMU consistent with Listing Policy section 3.1. No evaluation guidelines for the dissolved fractions of o,p'-DDD, o,p'-DDE, o,p'-DDT, or p,p'-DDMU for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. Because there are no appropriate evaluation guidelines, staff are unable to make a Listing decision. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing these water segment-pollutant combinations on the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No evaluation guidelines for the dissolved fractions of o,p'-DDD, o,p'-DDE, o,p'-DDT, or p,p'-DDMU for the protection of human, animal or aquatic life in fresh waters could be found that meet the requirements of section 6.1.3 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.
State Board Staff Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 29378, Multiple Pollutants Region 7      Imperial Valley Drains
LOE ID:	29877
Pollutant:	o,p'-DDD (Dichlorodiphenyldichloroethane)) | o,p'-DDE (Dichlorodiphenyldichloroethylene) | o,p'-DDT (Dichlorodiphenyltrichloroethane) | p,p'-DDMU
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	6
Number of Exceedances:
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).
Data Reference:	Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006). No evaluation guidelines for the dissolved fractions of o,p'-DDD, o,p'-DDE, o,p'-DDT, or p,p'-DDMU for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.
Objective/Criterion Reference:	Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.
Temporal Representation:	Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.
Environmental Conditions:
QAPP Information:	The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)