Draft 2008 California 303(d)/305(b) Integrated Report

Supporting Information

Regional Board 7 - Colorado River Basin Region

Water Body Name:	Colorado River and Associated Lakes and Reservoirs (California-Nevada border to Lake Havasu)
Water Body ID:	CAR7132000020080709122810
Water Body Type:	River & Stream

DECISION ID	8698
Pollutant:	.alpha.-BHC (Benzenehexachloride)
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule critieria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8698

LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8700
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:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting aquatic life uses, or protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8700

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8699
Pollutant:	.beta.-BHC (Benzenehexachloride)
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8699

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8701
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:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting aquatic life uses or protecting human health when consuming either water and organisms or organisms alone from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8701

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8739
Pollutant:	1, 1-dichloroethane
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8739

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8754
Pollutant:	1,1,1-Trichloroethane
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8754

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8765
Pollutant:	1,1,2,2-Tetrachloroethane
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
Weight of Evidence:	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 or the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8765

LOE ID:	7667
Pollutant:	1,1,2,2-Tetrachloroethane | 1,2-Dichloroethane | Benzene | Carbon tetrachloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water 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 six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segement of the river. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 0.001 mg/l Benzene, 0.0005 mg/l Carbon Tetrachloride, 0.0005 mg/l 1,2-Dichloroethane, and 0.001 mg/l 1,1,2,2-Tetrachloroethane (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7660
Pollutant:	1,1,2,2-Tetrachloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | Benzo(a)pyrene (PAHs) | Benzo[a]anthracene | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Carbon tetrachloride | 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:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: Benzene, 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 4.4 ug/l Carbon Tetrachloride, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, 3.2 ug/l 1,1-Dichloroethylene, 0.049 ug/l Indeno(1,2,3-cd) Pyrene, and 11 ug/l 1,1,2,2-Tetrachloroethane (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:	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
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8729
Pollutant:	1,1,2-Trichloroethane
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming organisms from these waters or the drinking water MCL. None of 6 water samples exceeded the California Toxics Rule criteria protecting human health when consuming water and organisms from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8729

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8740
Pollutant:	1,1-Dichloroethylene (DCE)/ Vinyldine Chloride
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL, and none of 6 water samples exceeded the California Toxics Rule criteria. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8740

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7660
Pollutant:	1,1,2,2-Tetrachloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | Benzo(a)pyrene (PAHs) | Benzo[a]anthracene | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Carbon tetrachloride | 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:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: Benzene, 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 4.4 ug/l Carbon Tetrachloride, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, 3.2 ug/l 1,1-Dichloroethylene, 0.049 ug/l Indeno(1,2,3-cd) Pyrene, and 11 ug/l 1,1,2,2-Tetrachloroethane (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:	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
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8753
Pollutant:	1,2,4-Trichlorobenzene
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8753

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8713
Pollutant:	1,2-Dichloroethane
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming organisms from these waters. None of 6 water samples exceeded either the California Toxics Rule criteria protecting human health when consuming water and organisms from these waters or the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8713

LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7667
Pollutant:	1,1,2,2-Tetrachloroethane | 1,2-Dichloroethane | Benzene | Carbon tetrachloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water 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 six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segement of the river. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 0.001 mg/l Benzene, 0.0005 mg/l Carbon Tetrachloride, 0.0005 mg/l 1,2-Dichloroethane, and 0.001 mg/l 1,1,2,2-Tetrachloroethane (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8742
Pollutant:	1,2-Dichloroethylene,-trans
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8742

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8714
Pollutant:	1,2-Dichloropropane
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
Weight of Evidence:	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. 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 7 water samples exceeded either the California Toxics Rule criteria protecting human health when consuming organisms from these waters or the drinking water MCL. None of 6 water samples exceeded the California Toxics Rule criteria protecting human health when consuming water and organisms from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8714

LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8697
Pollutant:	Acenaphthene
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8697

LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8731
Pollutant:	Aldrin
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
Weight of Evidence:	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 7 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8731

LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8737
Pollutant:	Aluminum
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
Weight of Evidence:	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 7 water samples exceeded either the primary drinking water MCL, or secondary MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8737

LOE ID:	7677
Pollutant:	Aluminum | Chloride | Copper | Manganese | Methyl Tertiary-Butyl Ether (MTBE) | Silver | Sulfates | Thiobencarb/Bolero | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Levels (SMCLs) for consumer acceptance were used for the following constituents: 0.2 mg/l Aluminum, 500 mg/l Chloride, 1 mg/l Copper, 0.05 mg/l Manganese, 0.005 mg/l MTBE, 0.1 mg/l Silver, 500 mg/l Sulfate, 0.001 mg/l Thiobencarb, and 5 mg/l Zinc (CCR, title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8703
Pollutant:	Anthracene
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
Weight of Evidence:	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 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8703

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8732
Pollutant:	Arsenic
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
Weight of Evidence:	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. 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 7 water samples exceeded either the California Toxics Rule criteria or the U.S. Fish and Wildlife Servie criteria. None of 7 water samples exceeded the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8732

LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7683
Pollutant:	Arsenic | Copper
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the USFWS Biological Effect Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	United State Fish and Wildlife Service (USFWS) Biological Effect Criteria for the protection of aquatic life uses were used for the following constituents: 0.25 mg/l Arsenic, and 15 mg/l Copper (USFWS, 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8762
Pollutant:	Atrazine
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
Weight of Evidence:	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 drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8762

LOE ID:	7670
Pollutant:	Atrazine | Simazine
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 Asses Water Quality:	Six water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 0.001 mg/l Atrazine, and 0.004 mg/l Simazine (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October. No sample was collected in October 2003.
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	8706
Pollutant:	Benzene
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming organisms from these waters. None of 6 water samples exceeded either the California Toxics Rule criteria protecting human health when consuming water and organisms from this water or the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8706

LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7667
Pollutant:	1,1,2,2-Tetrachloroethane | 1,2-Dichloroethane | Benzene | Carbon tetrachloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water 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 six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segement of the river. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 0.001 mg/l Benzene, 0.0005 mg/l Carbon Tetrachloride, 0.0005 mg/l 1,2-Dichloroethane, and 0.001 mg/l 1,1,2,2-Tetrachloroethane (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8725
Pollutant:	Benzo(a)pyrene (PAHs)
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
Weight of Evidence:	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 human health when consuming organisms from these waters. None of 7 water samples exceeded the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8725

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7660
Pollutant:	1,1,2,2-Tetrachloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | Benzo(a)pyrene (PAHs) | Benzo[a]anthracene | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Carbon tetrachloride | 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:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: Benzene, 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 4.4 ug/l Carbon Tetrachloride, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, 3.2 ug/l 1,1-Dichloroethylene, 0.049 ug/l Indeno(1,2,3-cd) Pyrene, and 11 ug/l 1,1,2,2-Tetrachloroethane (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:	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
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8704
Pollutant:	Benzo[a]anthracene
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
Weight of Evidence:	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 protecting human health when consuming organisms from these waters 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8704

LOE ID:	7660
Pollutant:	1,1,2,2-Tetrachloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | Benzo(a)pyrene (PAHs) | Benzo[a]anthracene | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Carbon tetrachloride | 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:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: Benzene, 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 4.4 ug/l Carbon Tetrachloride, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, 3.2 ug/l 1,1-Dichloroethylene, 0.049 ug/l Indeno(1,2,3-cd) Pyrene, and 11 ug/l 1,1,2,2-Tetrachloroethane (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:	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
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8720
Pollutant:	Benzo[b]fluoranthene
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
Weight of Evidence:	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 protecting human health when consuming organisms from these waters 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8720

LOE ID:	7660
Pollutant:	1,1,2,2-Tetrachloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | Benzo(a)pyrene (PAHs) | Benzo[a]anthracene | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Carbon tetrachloride | 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:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: Benzene, 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 4.4 ug/l Carbon Tetrachloride, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, 3.2 ug/l 1,1-Dichloroethylene, 0.049 ug/l Indeno(1,2,3-cd) Pyrene, and 11 ug/l 1,1,2,2-Tetrachloroethane (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:	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
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8707
Pollutant:	Bromoform
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming organisms from these waters. None of 6 water samples exceeded the California Toxics Rule criteria protecting human health when consuming water and organisms from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8707

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8738
Pollutant:	Cadmium
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
Weight of Evidence:	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. 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 7 water samples exceeded either the drinking water MCL or the Basin Plan water quality objective for the MUN beneficial use. None of 5 water samples exceeded the California Toxics Rule criteria. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8738

LOE ID:	7629
Pollutant:	Cadmium
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 Asses Water Quality:	Five water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Hardness Dependant 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 near the California Nevada Border.
Temporal Representation:	Five water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7691
Pollutant:	Cadmium | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Methoxychlor | Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	Basin Plan: Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the following limits: 10 ug/l Cadmium, 50 ug/l Lead, 4 ug/l Lindane/Hexachlorocyclohexane (HCH), 100 ug/l Methoxychlor, and 50 ug/l Silver (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8764
Pollutant:	Carbon tetrachloride
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
Weight of Evidence:	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. 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 Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. None of 6 water samples exceeded the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8764

LOE ID:	7660
Pollutant:	1,1,2,2-Tetrachloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | Benzo(a)pyrene (PAHs) | Benzo[a]anthracene | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Carbon tetrachloride | 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:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: Benzene, 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 4.4 ug/l Carbon Tetrachloride, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, 3.2 ug/l 1,1-Dichloroethylene, 0.049 ug/l Indeno(1,2,3-cd) Pyrene, and 11 ug/l 1,1,2,2-Tetrachloroethane (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:	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
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7667
Pollutant:	1,1,2,2-Tetrachloroethane | 1,2-Dichloroethane | Benzene | Carbon tetrachloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water 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 six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segement of the river. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 0.001 mg/l Benzene, 0.0005 mg/l Carbon Tetrachloride, 0.0005 mg/l 1,2-Dichloroethane, and 0.001 mg/l 1,1,2,2-Tetrachloroethane (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8733
Pollutant:	Chlordane
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
Weight of Evidence:	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 7 water samples exceeded either the California Toxics Rule criteria or the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8733

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8756
Pollutant:	Chloride
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
Weight of Evidence:	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 7 water samples exceeded the drinking water secondary MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8756

LOE ID:	7677
Pollutant:	Aluminum | Chloride | Copper | Manganese | Methyl Tertiary-Butyl Ether (MTBE) | Silver | Sulfates | Thiobencarb/Bolero | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Levels (SMCLs) for consumer acceptance were used for the following constituents: 0.2 mg/l Aluminum, 500 mg/l Chloride, 1 mg/l Copper, 0.05 mg/l Manganese, 0.005 mg/l MTBE, 0.1 mg/l Silver, 500 mg/l Sulfate, 0.001 mg/l Thiobencarb, and 5 mg/l Zinc (CCR, title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8708
Pollutant:	Chlorobenzene (mono)
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. None of 7 water samples exceeded the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8708

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8734
Pollutant:	Chromium (total)
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
Weight of Evidence:	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 7 water samples exceeded either the California Toxics Rule criteria or the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8734

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8766
Pollutant:	Chrysene (C1-C4)
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
Weight of Evidence:	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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8766

LOE ID:	7660
Pollutant:	1,1,2,2-Tetrachloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | Benzo(a)pyrene (PAHs) | Benzo[a]anthracene | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Carbon tetrachloride | 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:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: Benzene, 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 4.4 ug/l Carbon Tetrachloride, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, 3.2 ug/l 1,1-Dichloroethylene, 0.049 ug/l Indeno(1,2,3-cd) Pyrene, and 11 ug/l 1,1,2,2-Tetrachloroethane (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:	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
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8757
Pollutant:	Copper
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
Weight of Evidence:	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. Three lines 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 7 water samples exceeded either the California Toxics Rule criteria or the U.S. Fish and Wilife Service criteria. None of 7 water samples exceeded the drinking water secondary MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8757

LOE ID:	7616
Pollutant:	Copper
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7677
Pollutant:	Aluminum | Chloride | Copper | Manganese | Methyl Tertiary-Butyl Ether (MTBE) | Silver | Sulfates | Thiobencarb/Bolero | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Levels (SMCLs) for consumer acceptance were used for the following constituents: 0.2 mg/l Aluminum, 500 mg/l Chloride, 1 mg/l Copper, 0.05 mg/l Manganese, 0.005 mg/l MTBE, 0.1 mg/l Silver, 500 mg/l Sulfate, 0.001 mg/l Thiobencarb, and 5 mg/l Zinc (CCR, title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7683
Pollutant:	Arsenic | Copper
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the USFWS Biological Effect Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	United State Fish and Wildlife Service (USFWS) Biological Effect Criteria for the protection of aquatic life uses were used for the following constituents: 0.25 mg/l Arsenic, and 15 mg/l Copper (USFWS, 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8775
Pollutant:	DDT
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria for p,p'-DDT 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8775

LOE ID:	7641
Pollutant:	DDT
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentration (CMC) for pp'-DDT 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8768
Pollutant:	Diazinon
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
Weight of Evidence:	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 7 water samples exceeded the California Department of Fish and Game 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8768

LOE ID:	7687
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDFG Hazardous Assessment Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Fish and Games (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8705
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:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8705

LOE ID:	7660
Pollutant:	1,1,2,2-Tetrachloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | Benzo(a)pyrene (PAHs) | Benzo[a]anthracene | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Carbon tetrachloride | 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:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: Benzene, 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 4.4 ug/l Carbon Tetrachloride, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, 3.2 ug/l 1,1-Dichloroethylene, 0.049 ug/l Indeno(1,2,3-cd) Pyrene, and 11 ug/l 1,1,2,2-Tetrachloroethane (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:	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
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8712
Pollutant:	Dichlorobromomethane
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming organisms from these waters. None of 6 water samples exceeded the California Toxics Rule criteria protecting human health when consuming water and organisms from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8712

LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8769
Pollutant:	Dichloromethane
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
Weight of Evidence:	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 is available in the administrative record to assess this pollutant. Both lines of evidence received a Use Rating of Insufficient Information because there was only one sample reported in each line of evidence. According to Table 3.1 of the Listing Policy, the minimum number of samples required is 2. 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 1 water sample exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8769

LOE ID:	7644
Pollutant:	Dichloromethane | Methyl bromide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	One water sample was collected in 5/2002 at 1 location along this segment of the Colorado River. This sample did not exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 48 ug/l Methyl Bromide, and 5 ug/l Dichloromethane (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:	A sample was collected near the California Nevada Border.
Temporal Representation:	One water sample was collected. A water sample was collected in 5/2002.
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).
LOE ID:	7657
Pollutant:	Dichloromethane | Methyl bromide | Vinyl chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	One water sample was collected in 5/2002 at 1 location along this segment of the Colorado River. This sample did not exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 4000 ug/l Methyl Bromide, 1600 ug/l Dichloromethane, and 525 ug/l Vinyl Chloride (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:	A sample was collected near the California Nevada Border.
Temporal Representation:	One water sample was collected. A water sample was collected in 5/2002.
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	8774
Pollutant:	Dieldrin
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
Weight of Evidence:	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 7 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8774

LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8702
Pollutant:	Endosulfan sulfate
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8702

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8715
Pollutant:	Endrin
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. None of 7 water samples exceeded either the drinking water MCL or the California Toxcis Rule criteria protecting aquatic life uses. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8715

LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8716
Pollutant:	Endrin aldehyde
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8716

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8772
Pollutant:	Enterococcus
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
Weight of Evidence:	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. Two lines of evidence are available in the administrative record to assess this pollutant. One 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. One of 4 samples exceeded the Basin Plan Enterococcus water quality objective that protects RECI beneficial uses, and none of 4 samples exceeded the Basin Plan Enterococcus water quality objective that protect RECII beneficial uses. These do 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8772

LOE ID:	7610
Pollutant:	Enterococcus
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Non-Contact Recreation
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Four water samples were collected biannually from 5/2002 through 11/2003 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	Basin Plan:In the Colorado River the maximum allowable Enterococcus density is 305 MPN/ 100 ml (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected near the California Nevada Border
Temporal Representation:	Four water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 11/2003 from the Nevada Border. Samples were generally collected in May and October.
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).
LOE ID:	7607
Pollutant:	Enterococcus
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Water Contact Recreation
Number of Samples:	4
Number of Exceedances:	1
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Four water samples were collected biannually from 5/2002 through 11/2003 at 1 location along this segment of the Colorado River. Of these total samples, 1 exceeded the Basin Plan Objective. The exceedance was found in a sample collected on 11/03/2003 from near the Nevada Border (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	Basin Plan:In the Colorado River the maximum allowable Enterococcus density is 61 MPN/ 100 ml (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Four water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 11/2003 from the Nevada Border. Samples were generally collected in May and October. The exceedance was found in a sample collected on 11/03/2003.
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	8773
Pollutant:	Escherichia coli (E. Coli)
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
Weight of Evidence:	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. 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 4 water samples exceeded the Basin Plan E. coli water quality objectives that protect RECI and RECII beneficial uses 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8773

LOE ID:	7694
Pollutant:	Escherichia coli (E. Coli)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Water Contact Recreation
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Four water samples were collected biannually from 5/2002 through 11/2003 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	Basin Plan:In the Colorado River the maximum allowable E. coli density is 235 MPN/ 100 ml (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected near the Caliornia Nevada Border.
Temporal Representation:	Four water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 11/2003 from the Nevada Border. Samples were generally collected in May and October.
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).
LOE ID:	7702
Pollutant:	Escherichia coli (E. Coli)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Non-Contact Recreation
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Four water samples were collected biannually from 5/2002 through 11/2003 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	Basin Plan:In the Colorado River the maximum allowable E. coli density is 1175 MPN/ 100 ml (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Four water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 11/2003 from the Nevada Border. Samples were generally collected in May and October.
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	8717
Pollutant:	Ethylbenzene
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. None of 7 water samples exceeded the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8717

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8718
Pollutant:	Fluoranthene
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8718

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8719
Pollutant:	Fluorene
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8719

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8735
Pollutant:	Heptachlor
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
Weight of Evidence:	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 7 water samples exceeded either the California Toxics Rule criteria or the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8735

LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8736
Pollutant:	Heptachlor epoxide
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
Weight of Evidence:	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 7 water samples exceeded either the California Toxics Rule criteria or the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8736

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7632
Pollutant:	.alpha.-Endosulfan (Endosulfan 1) | .beta.-Endosulfan (Endosulfan 2) | Aldrin | Arsenic | Chlordane | Chromium (total) | Dieldrin | Endrin | Heptachlor | Heptachlor epoxide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 1724 ug/l Chromium, 0.24 ug/l Dieldrin, 0.086 ug/l Endrin, 0.52 ug/l Heptachlor, and 0.52 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8743
Pollutant:	Hexachlorobenzene/ HCB
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8743

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8721
Pollutant:	Hexachlorobutadiene
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
Weight of Evidence:	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 human health when consuming water and organisms from these waters. None of 7 water samples exceeded the California Toxcis Rule criteria protecting human health when consuming organisms from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8721

LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8726
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:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8726

LOE ID:	7660
Pollutant:	1,1,2,2-Tetrachloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | Benzo(a)pyrene (PAHs) | Benzo[a]anthracene | Benzo[b]fluoranthene | Benzo[k]fluoranthene | Carbon tetrachloride | 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:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location on this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: Benzene, 0.049 ug/l Benzo[a]Anthracene, 0.049 ug/l Benzo[a]Pyrene, 0.049 Benzo[b]Fluoranthene, 0.049 ug/l Benzo[k]Fluoranthene, 4.4 ug/l Carbon Tetrachloride, 0.049 ug/l Chrysene, 0.049 ug/l Dibenzo(a,h)Anthracene, 3.2 ug/l 1,1-Dichloroethylene, 0.049 ug/l Indeno(1,2,3-cd) Pyrene, and 11 ug/l 1,1,2,2-Tetrachloroethane (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:	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
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8767
Pollutant:	Lead
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
Weight of Evidence:	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 7 water samples exceeded either the California Toxics Rule criteria, or the Basin Plan water quality objective to protect the MUN beneficial use. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8767

LOE ID:	7635
Pollutant:	Lead | Nickel | Silver | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR hardness dependent criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule Hardness Dependent Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: Lead,Nickel, Silver, 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7691
Pollutant:	Cadmium | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Methoxychlor | Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	Basin Plan: Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the following limits: 10 ug/l Cadmium, 50 ug/l Lead, 4 ug/l Lindane/Hexachlorocyclohexane (HCH), 100 ug/l Methoxychlor, and 50 ug/l Silver (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8744
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:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	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 7 water samples exceeded either the drinking water MCL or the Basin Plan water quality objective protecting the MUN beneficial use. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8744

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7691
Pollutant:	Cadmium | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Methoxychlor | Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	Basin Plan: Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the following limits: 10 ug/l Cadmium, 50 ug/l Lead, 4 ug/l Lindane/Hexachlorocyclohexane (HCH), 100 ug/l Methoxychlor, and 50 ug/l Silver (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8758
Pollutant:	Manganese
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
Weight of Evidence:	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 7 water samples exceeded the drinking water secondary MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8758

LOE ID:	7677
Pollutant:	Aluminum | Chloride | Copper | Manganese | Methyl Tertiary-Butyl Ether (MTBE) | Silver | Sulfates | Thiobencarb/Bolero | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Levels (SMCLs) for consumer acceptance were used for the following constituents: 0.2 mg/l Aluminum, 500 mg/l Chloride, 1 mg/l Copper, 0.05 mg/l Manganese, 0.005 mg/l MTBE, 0.1 mg/l Silver, 500 mg/l Sulfate, 0.001 mg/l Thiobencarb, and 5 mg/l Zinc (CCR, title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8722
Pollutant:	Mercury
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. None of 7 water samples exceeded either the drinking water MCL or the California Toxics Rule criteria protecting aquatic life uses. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8722

LOE ID:	7638
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criterion Maximum Concentration (CMC) of 1.4 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8745
Pollutant:	Methoxychlor
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
Weight of Evidence:	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. 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 7 water samples exceeded either the drinking water MCL or the USEPA Drinking Water criteria. None of 7 water samples exceeded the Basin Plan water quality objective protecting the MUN beneficial use. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8745

LOE ID:	7691
Pollutant:	Cadmium | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Methoxychlor | Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	Basin Plan: Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the following limits: 10 ug/l Cadmium, 50 ug/l Lead, 4 ug/l Lindane/Hexachlorocyclohexane (HCH), 100 ug/l Methoxychlor, and 50 ug/l Silver (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7626
Pollutant:	Methoxychlor
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the USEPA criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	USEPA Drinking Water Criteria of 40 ug/l for the protection of drinking water uses (USEPA, 2002).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8746
Pollutant:	Methyl Tertiary-Butyl Ether (MTBE)
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
Weight of Evidence:	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 7 water samples exceeded either the primary drinking water MCL or the secondary MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8746

LOE ID:	7677
Pollutant:	Aluminum | Chloride | Copper | Manganese | Methyl Tertiary-Butyl Ether (MTBE) | Silver | Sulfates | Thiobencarb/Bolero | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Levels (SMCLs) for consumer acceptance were used for the following constituents: 0.2 mg/l Aluminum, 500 mg/l Chloride, 1 mg/l Copper, 0.05 mg/l Manganese, 0.005 mg/l MTBE, 0.1 mg/l Silver, 500 mg/l Sulfate, 0.001 mg/l Thiobencarb, and 5 mg/l Zinc (CCR, title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8770
Pollutant:	Methyl bromide
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
Weight of Evidence:	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. Both lines of evidence received a Use Rating of Insufficient Information because there was only one sample reported in the each of evidence. According to Table 3.1 of the Listing Policy, the minimum number of samples required is 2. 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 1 water sample exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8770

LOE ID:	7644
Pollutant:	Dichloromethane | Methyl bromide
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	One water sample was collected in 5/2002 at 1 location along this segment of the Colorado River. This sample did not exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 48 ug/l Methyl Bromide, and 5 ug/l Dichloromethane (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:	A sample was collected near the California Nevada Border.
Temporal Representation:	One water sample was collected. A water sample was collected in 5/2002.
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).
LOE ID:	7657
Pollutant:	Dichloromethane | Methyl bromide | Vinyl chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	One water sample was collected in 5/2002 at 1 location along this segment of the Colorado River. This sample did not exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 4000 ug/l Methyl Bromide, 1600 ug/l Dichloromethane, and 525 ug/l Vinyl Chloride (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:	A sample was collected near the California Nevada Border.
Temporal Representation:	One water sample was collected. A water sample was collected in 5/2002.
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	8747
Pollutant:	Molinate
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8747

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8723
Pollutant:	Nickel
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. None of 7 samples exceeded either the drinking water MCL or the California Toxics Rule criteria protecting aquatic life uses. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8723

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7635
Pollutant:	Lead | Nickel | Silver | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR hardness dependent criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule Hardness Dependent Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: Lead,Nickel, Silver, 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8748
Pollutant:	Nitrate as Nitrate (NO3)
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8748

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8749
Pollutant:	Nitrogen, Nitrite
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8749

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8750
Pollutant:	PCBs (Polychlorinated biphenyls)
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8750

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8776
Pollutant:	Perchlorate
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8776

LOE ID:	7613
Pollutant:	Perchlorate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Level (MCL) of 0.006 mg/l for the protection of human health (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8724
Pollutant:	Pyrene
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8724

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8751
Pollutant:	Selenium
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8751

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8759
Pollutant:	Silver
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria or the Basin Plan water quality objective to protect the MUN beneficial use. None of 7 water samples exceeded the drinking water secondary MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8759

LOE ID:	7677
Pollutant:	Aluminum | Chloride | Copper | Manganese | Methyl Tertiary-Butyl Ether (MTBE) | Silver | Sulfates | Thiobencarb/Bolero | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Levels (SMCLs) for consumer acceptance were used for the following constituents: 0.2 mg/l Aluminum, 500 mg/l Chloride, 1 mg/l Copper, 0.05 mg/l Manganese, 0.005 mg/l MTBE, 0.1 mg/l Silver, 500 mg/l Sulfate, 0.001 mg/l Thiobencarb, and 5 mg/l Zinc (CCR, title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7691
Pollutant:	Cadmium | Lead | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Methoxychlor | Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	Basin Plan: Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the following limits: 10 ug/l Cadmium, 50 ug/l Lead, 4 ug/l Lindane/Hexachlorocyclohexane (HCH), 100 ug/l Methoxychlor, and 50 ug/l Silver (CRBRWQCB, 2006).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7635
Pollutant:	Lead | Nickel | Silver | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR hardness dependent criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule Hardness Dependent Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: Lead,Nickel, Silver, 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8763
Pollutant:	Simazine
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
Weight of Evidence:	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 drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8763

LOE ID:	7670
Pollutant:	Atrazine | Simazine
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 Asses Water Quality:	Six water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 0.001 mg/l Atrazine, and 0.004 mg/l Simazine (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Six water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October. No sample was collected in October 2003.
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	8778
Pollutant:	Specific Conductance
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
Weight of Evidence:	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 7 water samples exceeded the drinking water secondary MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8778

LOE ID:	7680
Pollutant:	Specific Conductance
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven measurements were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total measurements, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Level (SMCL) of 1600 umhos for consumer acceptance (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Measurements were collected near the Califonria Nevada Border.
Temporal Representation:	Seven water quality measurements were collected. Water quality measurements were generally collected biannually from 5/2002 through 5/2005 from the Nevada Border. Measurements were usually collected in May and October.
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	8779
Pollutant:	Styrene
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
Weight of Evidence:	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. This line of evidence received a Use Rating of Insufficient Information because there was only one sample reported in the line of evidence. According to Table 3.1 of the Listing Policy, the minimum number of samples required is 2. This sample did not 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 1 water sample exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8779

LOE ID:	7654
Pollutant:	Styrene | Trichlorofluoromethane (CFC-11)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	One water sample was collected in 5/2002 at 1 location along this segment of the Colorado River. This sample did not exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 100 ug/l Styrene, and 150 ug/l Trichlorofluoromethane (CFC-11) (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Sample was collected near the California Nevada Border.
Temporal Representation:	One water sample was collected. A water sample was collected in 5/2002.
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	8760
Pollutant:	Sulfates
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
Weight of Evidence:	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 7 water samples exceeded the drinking water secondary MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8760

LOE ID:	7677
Pollutant:	Aluminum | Chloride | Copper | Manganese | Methyl Tertiary-Butyl Ether (MTBE) | Silver | Sulfates | Thiobencarb/Bolero | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Levels (SMCLs) for consumer acceptance were used for the following constituents: 0.2 mg/l Aluminum, 500 mg/l Chloride, 1 mg/l Copper, 0.05 mg/l Manganese, 0.005 mg/l MTBE, 0.1 mg/l Silver, 500 mg/l Sulfate, 0.001 mg/l Thiobencarb, and 5 mg/l Zinc (CCR, title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8727
Pollutant:	Tetrachloroethylene/PCE
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
Weight of Evidence:	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. 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 7 water samples exceeded either the California Toxics Rule criteria protecting human health when consuming organisms from these waters or the drinking water MCL. None of 6 water samples exceeded the California Toxics Rule criteria protecting human health when consuming water and organisms from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8727

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8752
Pollutant:	Thiobencarb/Bolero
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL or the secondary MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8752

LOE ID:	7677
Pollutant:	Aluminum | Chloride | Copper | Manganese | Methyl Tertiary-Butyl Ether (MTBE) | Silver | Sulfates | Thiobencarb/Bolero | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Levels (SMCLs) for consumer acceptance were used for the following constituents: 0.2 mg/l Aluminum, 500 mg/l Chloride, 1 mg/l Copper, 0.05 mg/l Manganese, 0.005 mg/l MTBE, 0.1 mg/l Silver, 500 mg/l Sulfate, 0.001 mg/l Thiobencarb, and 5 mg/l Zinc (CCR, title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8728
Pollutant:	Toluene
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming water and organisms or organisms only from these waters. None of 7 water samples exceeded the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8728

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8730
Pollutant:	Trichloroethylene/TCE
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
Weight of Evidence:	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. 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 7 water samples exceeded either the California Toxics Rule criteria protecting human health when consuming organisms from these waters, or the drinking water MCL. None of 6 water samples exceeded the California Toxics Rule criteria protecting human health when consuming water and organisms from these waters. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8730

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7647
Pollutant:	1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Benzene | Bromoform | Carbon tetrachloride | Dichlorobromomethane | Hexachlorobutadiene | Tetrachloroethylene/PCE | Trichloroethylene/TCE
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	6
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven samples were taken at 1 location along this segment of the Colorado River. One water sample result could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The six acceptable water quality samples were generally collected and analyzed twice a year from 10/2002 through 5/2005 at 1 location along this segment of the river. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1.2 ug/l Benzene, 4.3 ug/l Bromoform, 0.25 ug/l Carbon Tetrachloride, 0.56 ug/l Dichlorobromomethane, 0.38 ug/l 1,2-Dichloroethane, 0.52 ug/l 1,2-Dichloropropane, 0.44 ug/l Hexachlorobutadiene, 0.80 ug/l Tetrachloroehtylene, 0.6 ug/l 1,1,2-Trichloroethane, and 2.7 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8780
Pollutant:	Trichlorofluoromethane (CFC-11)
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
Weight of Evidence:	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. This line of evidence received a Use Rating of Insufficient Information because there was only one sample reported in the line of evidence. According to Table 3.1 of the Listing Policy, the minimum number of samples required is 2. This sample did not 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 1 water sample exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8780

LOE ID:	7654
Pollutant:	Styrene | Trichlorofluoromethane (CFC-11)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	One water sample was collected in 5/2002 at 1 location along this segment of the Colorado River. This sample did not exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 100 ug/l Styrene, and 150 ug/l Trichlorofluoromethane (CFC-11) (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Sample was collected near the California Nevada Border.
Temporal Representation:	One water sample was collected. A water sample was collected in 5/2002.
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	8781
Pollutant:	Turbidity
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
Weight of Evidence:	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 7 water samples exceeded the drinking water secondary MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8781

LOE ID:	7604
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water quality measurements were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total measurements, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Level (SMCL) of 5 NTU for consumer acceptance (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Measurements were collected near the California Nevada Border.
Temporal Representation:	Seven water quality measurements were collected. Water quality measurements were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Measurmements were usually collected in May and October.
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	8771
Pollutant:	Vinyl chloride
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
Weight of Evidence:	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. One line of evidence received a Use Rating of Insufficient Information because there was only one sample reported in the line of evidence. According to Table 3.1 of the Listing Policy, the minimum number of samples required is 2. 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 1 water sample 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8771

LOE ID:	7657
Pollutant:	Dichloromethane | Methyl bromide | Vinyl chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	One water sample was collected in 5/2002 at 1 location along this segment of the Colorado River. This sample did not exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 4000 ug/l Methyl Bromide, 1600 ug/l Dichloromethane, and 525 ug/l Vinyl Chloride (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:	A sample was collected near the California Nevada Border.
Temporal Representation:	One water sample was collected. A water sample was collected in 5/2002.
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	8755
Pollutant:	Xylenes (total) (mixed)
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8755

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8761
Pollutant:	Zinc
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria, or the drinking water secondary MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8761

LOE ID:	7635
Pollutant:	Lead | Nickel | Silver | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR hardness dependent criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule Hardness Dependent Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: Lead,Nickel, Silver, 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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7677
Pollutant:	Aluminum | Chloride | Copper | Manganese | Methyl Tertiary-Butyl Ether (MTBE) | Silver | Sulfates | Thiobencarb/Bolero | Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH SMCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Secondary Maximum Contaminant Levels (SMCLs) for consumer acceptance were used for the following constituents: 0.2 mg/l Aluminum, 500 mg/l Chloride, 1 mg/l Copper, 0.05 mg/l Manganese, 0.005 mg/l MTBE, 0.1 mg/l Silver, 500 mg/l Sulfate, 0.001 mg/l Thiobencarb, and 5 mg/l Zinc (CCR, title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64449 Secondary Drinking Water Standards
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8741
Pollutant:	cis-1,2-Dichloroethylene
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
Weight of Evidence:	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 7 water samples exceeded the drinking water MCL 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8741

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8710
Pollutant:	m-Dichlorobenzene
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
Weight of Evidence:	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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters, and 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8710

LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8709
Pollutant:	o-Dichlorobenzene
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxics Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. None of 7 water samples exceeded the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8709

LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8711
Pollutant:	p-Dichlorobenzene (DCB)
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
Weight of Evidence:	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. 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 7 water samples exceeded the California Toxcis Rule criteria protecting human health when consuming either water and organisms or organisms only from these waters. None of 7 water samples exceeded the drinking water MCL. 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8711

LOE ID:	7673
Pollutant:	1, 1-dichloroethane | 1,1,1-Trichloroethane | 1,1,2-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2,4-Trichlorobenzene | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Aluminum | Arsenic | Benzo(a)pyrene (PAHs) | Cadmium | Chlordane | Chlorobenzene (mono) | Chromium (total) | Endrin | Ethylbenzene | Heptachlor | Heptachlor epoxide | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Mercury | Methoxychlor | Methyl Tertiary-Butyl Ether (MTBE) | Molinate | Nickel | Nitrate | Nitrogen, Nitrite | PCBs (Polychlorinated biphenyls) | Selenium | Tetrachloroethylene/PCE | Thiobencarb/Bolero | Toluene | Trichloroethylene/TCE | Xylenes (total) (mixed) | cis-1,2-Dichloroethylene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were generally collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CDPH MCL (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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).
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:	California Department of Public Health (CDPH) Drinking Water Maximum Contaminant Levels (MCLs) for the protection of human health were used for the following constituents: 1 mg/l Aluminum, 0.05 mg/l Arsenic, 0.0002 mg/l Benzo[a]Pyrene, 0.005 mg/l Cadmium, 0.0001 mg/l Chlordane, 0.05 mg/l Chromium, 0.6 mg/l o-Dichlorobenzene, 0.5 mg/l p-Dichlorobenzene, 0.005 mg/l 1,1-Dichloroethane, 0.006 mg/l 1,1-Dichloroethylene, 0.006 mg/l cis-1,2-Dichloroethylene, 0.01 mg/l 1,2-Dichloroethylene,-trans, 0.005 mg/l 1,2-Dichloropropane, 0.002 mg/l Endrin, 0.3 mg/l Ethylbenzene, 0.00001mg/l Heptachlor, 0.00001 mg/l Heptachlor Epoxide, 0.001 mg/l Hexachlorobenzene, 0.0002 mg/l Lindane/Hexachlorocyclohexane (HCH), 0.002 mg/l Mercury, 0.030 mg/l Methoxychlor, 0.013 mg/l Methly-Tertiary-Butyl Ether (MTBE), 0.02 mg/l Molinate, 0.070 mg/l Chlorobenzene (mono), 0.1 mg/l Nickel, 0.045 mg/l Nitrate, 0.001 mg/l Nitrite as N, 0.0005 mg/l PCBs (total), 0.05 mg/l Selenium, 0.005 mg/l Tetrachloroethylene, 0.07 mg/l Thiobencarb, 0.15 mg/l Toluene, 0.005 mg/l 1,2,4-Trichlorobenzene, 0.2 mg/l 1,1,1-Trichloroethane, 0.005 mg/l 1,1,2-Trichloroethane, 0.005 mg/l Trichloroethylene, and 1.75 mg/l Xylene (CCR, Title 22).
Guideline Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
Spatial Representation:	Samples were collected near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7663
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | 1,1,2-Trichloroethane | 1,2-Dichloroethane | 1,2-Dichloropropane | Acenaphthene | Anthracene | Benzene | Bromoform | Chlorobenzene (mono) | Dichlorobromomethane | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Hexachlorobutadiene | Mercury | Nickel | Pyrene | Tetrachloroethylene/PCE | Toluene | Trichloroethylene/TCE | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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: 2700 ug/l Acenaphthene, 71 ug/l Benzene, 0.014 ug/l alpha-BHC, 240 ug/l alpha-Endosulfan, 110000 ug/l Anthracene, 0.046 beta-BHC, 240 ug/l beta-Endosulfan, 360 ug/l Bromoform, 21000 ug/l Chlorobenzene, 46 ug/l Dichlorobromomethane, 17000 ug/l o-Dichlorobenzene, 2600 ug/l m-Dichlorobenzene, 2600 ug/l p-Dichlorobenzene, 99 ug/l 1,2-Dichloroethane, 39 ug/l 1,2-Dichloropropane, 240 ug/l Endosulfan Sulfate, 0.81 ug/l Endrin, 0.81 ug/l Endrin Aldehyde, 29000 ug/l Ethylbenzene, 370 ug/l Fluoranthene, 14000 ug/l Fluorene, 50 ug/l Hexachlorobutadiene, 0.051 ug/l Mercury, 4600 ug/l Nickel, 11000 ug/l Pyrene, 8.85 ug/l Tetrachloroethylene, 200000 ug/l Toluene, 42 ug/l 1,1,2-Trichloroethane, and 81 ug/l Trichloroethylene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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).
LOE ID:	7650
Pollutant:	.alpha.-BHC (Benzenehexachloride) | .alpha.-Endosulfan (Endosulfan 1) | .beta.-BHC (Benzenehexachloride) | .beta.-Endosulfan (Endosulfan 2) | Acenaphthene | Anthracene | Chlorobenzene (mono) | Endosulfan sulfate | Endrin | Endrin aldehyde | Ethylbenzene | Fluoranthene | Fluorene | Mercury | Nickel | Pyrene | Toluene | m-Dichlorobenzene | o-Dichlorobenzene | p-Dichlorobenzene (DCB)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Asses Water Quality:	Seven water samples were collected biannually from 5/2002 through 5/2005 at 1 location along this segment of the Colorado River. Of these total samples, none exceeded the CTR criteria (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
Water Quality Objective/Criterion:	California Toxics Rule (CTR) Criteria for the protection of human health when consuming water and organisms from aquatic systems were used for the following constituents: 1200 ug/l Acenaphthene, 0.0093 ug/l alpha-BHC, 110 ug/l alpha-Endosulfan, 9600 ug/l Anthracene, 0.014 ug/l beta-BHC, 110 ug/l beta-Endosulfan, 680 ug/l Chlorobenzene, 1300 ug/l Copper, 2700 ug/l o-Dichlorobenzene, 400 ug/l m-Dichlorobenzene, 400 ug/l p-Dichlorobenzene, 110 ug/l Endosulfan Sulfate, 0.76 ug/l Endrin, 0.76 Endrin Aldehyde, 3100 ug/l Ethylbenzene, 300 ug/l Fluoranthene, 1300 ug/l Fluorene, 0.050 ug/l Mercury, 610 ug/l Nickel, 960 ug/l Pyrene,and 6800 ug/l Toluene (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 near the California Nevada Border.
Temporal Representation:	Seven water samples were collected. Water samples were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Samples were usually collected in May and October.
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	8777
Pollutant:	pH
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
Weight of Evidence:	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 5 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 8777

LOE ID:	7705
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
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 Asses Water Quality:	Seven water quality measurements were taken at 1 location along this segment of the Colorado River. Two measurements could not be used in this assessment because of equipment failure or lack of proper documentation. The 5 acceptable measurements were collected from 5/2002 through 5/2005 at 1 location. Of these total measurements, none exceeded the Basin Plan Objective (SWAMP, 2007).
Data Reference:	Data for organic and inorganic constituents in water and sediment samples collected from waterbodies located in the Colorado River Basin-Region 7. May 2002-May 2005.
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 (Basin Plan), Colorado River Basin-Region 7. Palm Desert, CA.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Measurements were collected near the California Nevada Border.
Temporal Representation:	Seven water quality measurements were collected. Water quality measurements were generally collected and analyzed biannually from 5/2002 through 5/2005 from the Nevada Border. Measurmements were usually collected in May and October.
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).