Final California 2018 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: Orestimba Creek (above Kilburn Road)
Water Body ID: CAR5422003219990126113826
Water Body Type: River & Stream
 
DECISION ID
93674
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Diuron
Final Listing Decision: Delist from 303(d) list (being addressed by action other than TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by action other than TMDL)(2016)
Revision Status Revised
Reason for Delisting: Applicable WQS attained; reason for recovery unspecified
Expected Attainment Date: 2021
Implementation Action Other than TMDL: This listing is being addressed through the implementation of the Central Valley Regional Water Quality Control Board Irrigated Lands Regulatory program (ILRP) Waste Discharge Requirements (WDRs) for Growers within the Western San Joaquin River Watershed that are Members of the Third-Party Group (Order R5-2014-0002-R2) and in Waste Discharge Requirements General Order for Discharges from Irrigated Lands within the Central Valley Region for Dischargers not Participating in a Third-party Group (Order R5-2013-0100). The sources of diuron to this waterbody segment have been identified as offsite movement of diuron from diuron applications by the agricultural dischargers regulated by the CRWQCB-CVR WDRs. The WDRs include a time schedule, milestones and a monitoring and reporting program. The WDRs require growers to develop and implement water quality management plans iteratively to attain water quality objectives as soon as possible, but no later than ten years from the identification of water quality exceedances. The WDRs monitoring and reporting program requires growers to regularly monitor water bodies with management plans to assess progress at meeting standards and regularly report monitoring results to the Regional Board. A management plan for diuron in Orestimba Creek was developed in 2011 and is being implemented and monitoring is ongoing. Agricultural management practices being used to reduce offsite movement of diuron into surface water include alternative weed management practices, pesticide application practices, vegetation management and water management practices, pesticide application practices, vegetation management and water management practices, all of which are effective in reducing offsite movement of diuron into surface water. The WDRs require management practices to be iteratively improved through updates of the management plans until water quality criteria are achieved. The diuron criteria are expected to be attained through continued implementation and improvement of management practices within the required 10-year compliance time frame.
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section 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. Three of the sixty samples exceeded the criteria

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. A water quality management plan for diuron was approved by the Central Valley Water Board Irrigated Lands Regulatory Program and was implemented by growers for management practices to address diuron exceedances.
4. Orestimba Creek (above Kilburn Road) was originally identified as impaired by diuron in 2014.
5. Three of sixty samples exceeded the criteria and this does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy.
6. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 93674, Diuron
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 130292
 
Pollutant: Diuron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 37
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Westside San Joaquin River Watershed Coalition data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 37 samples exceeded the water quality standard for Diuron.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Westside San Joaquin River Watershed Coalition
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the 4-day average concentration of diuron does not exceed 1.3 ug/L (UC Davis Aquatic Life Criteria).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: The samples were collected at 1 monitoring site(s) (541STC519)
Temporal Representation: The samples were collected between the dates of 2011-01-03 and 2015-06-09
Environmental Conditions:
QAPP Information: Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board  
QAPP Information Reference(s): Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board
 
Line of Evidence (LOE) for Decision ID 93674, Diuron
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78589
 
Pollutant: Diuron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 23
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: three of the 23 samples exceed the criterion for Diuron
Data Reference: Data for Various Pollutants in Merced Irrigation District, 2005-2008.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." Aquatic life should not be affected unacceptably if the 4-day average concentration of Diuron, 1.3 ug/L, is not exceeded more than once every three years on the average (UC Davis Aquatic Life Criterion).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: III. Diuron. Reviews of Environmental Contamination and Toxicology 216:105-141.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at one monitoring site [Orestimba Creek @ Hwy 33) - 541STC519]
Temporal Representation: Data was collected approximately monthly between 7/11/2006 and 8/11/2009
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
73111
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Toxicity
Final Listing Decision: Do Not Delist from 303(d) list (being addressed with action other than TMDL)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status Revised
Sources: A Source Unknown
Expected Attainment Date: 2024
Implementation Action Other than TMDL: This listing is being addressed through the implementation of the Central Valley Water Board Irrigated Lands Regulatory program (ILRP), General Order R5-2014-0002, for the Westside San Joaquin River Watershed Coalition (Coalition). The Coalition has two active management plans for toxicity that were developed prior to the General Order. The Westside San Joaquin River Watershed Coalition Management Plan General Approach was developed in 2008 and the Westside San Joaquin River Watershed Coalition Focused Watershed Management Plan II for Westley Wasteway, Del Puerto Creek, Orestimba Creek was developed in 2010. Both management plans stated the sources of toxicity identify agricultural practices as a significant contributor and require ongoing monitoring of the water bodies to assess progress at meeting water quality standards. Agricultural management practices to reduce toxicity in surface water include integrated pest management programs, conversion to high-efficiency irrigation systems, vegetation management and water management practices. The management plans are required to be updated until water quality criteria are achieved.
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 and 4.6 of the Listing Policy. Under section 4.1a single line of evidence is necessary to assess listing status.

Four lines of evidence are available in the administrative record to assess pollutant. Eleven of 17 samples exceed the guideline in sediment and 17 of 77 samples exceed the guideline in water.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Eleven of 17 samples exceed the guideline in sediment and 17 of 77 samples exceed the guideline in water and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy.
4. A water quality management plan for toxicity for Orestimba Creek (above Kilburn Road) was approved by the Central Valley Water Board Irrigated Lands Regulatory Program. Management practices were implemented by growers to address toxicity exceedances.
5. Orestimba Creek (above Kilburn Road) was originally identified as impaired by toxicity in 2014.
6. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are being met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 73111, Toxicity
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 59325
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 6
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Nine samples were collected to evaluate sediment toxicity. Six of the samples exhibited significant toxicity. The toxicity tests included survival of Hyalella azteca. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day at the same location with the same lab sample id (if provided).
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 5 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. For SWAMP data exceedances are counted using the significant effect code: S equals significant, SG equals significantly greater and SL equals significantly lower. If a sample has any one of these codes, it will be considered an exceedance.
Guideline Reference: Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064
 
Spatial Representation: The samples were collected at Orestimba Creek at Hwy 33.
Temporal Representation: The samples were collected from September 2004 to March 2009.
Environmental Conditions:
QAPP Information: Collected under the Monitoring and Reporting Program Plans for the Westside Water Quality Coalition.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 73111, Toxicity
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 131287
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 38
Number of Exceedances: 6
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: 6 of the 38 samples collected by Westside San Joaquin River Watershed Coalition for Orestimba Creek (above Kilburn Road) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Pimephales promelas, for Survival, Selenastrum capricornutum, for Total Cell Count, Ceriodaphnia dubia, for Survival
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Westside San Joaquin River Watershed Coalition
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 stations. Monitoring site(s): ( 541STC519 )
Temporal Representation: The samples were collected between the dates of 2011-01-03 and 2015-06-09.
Environmental Conditions:
QAPP Information: Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board  
QAPP Information Reference(s): Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board
 
Line of Evidence (LOE) for Decision ID 73111, Toxicity
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 131374
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 5
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: 5 of the 8 samples collected by Westside San Joaquin River Watershed Coalition for Orestimba Creek (above Kilburn Road) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca, for Survival
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Westside San Joaquin River Watershed Coalition
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 stations. Monitoring site(s): ( 541STC519 )
Temporal Representation: The samples were collected between the dates of 2010-09-13 and 2015-03-09.
Environmental Conditions:
QAPP Information: Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board  
QAPP Information Reference(s): Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board
 
Line of Evidence (LOE) for Decision ID 73111, Toxicity
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 59324
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 39
Number of Exceedances: 11
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Thirty-nine samples were collected to evaluate water toxicity. Eleven of the samples exhibited significant toxicity. The toxicity tests included survival of Ceriodaphnia dubia, survival of Pimephales promelas, and cell count of Selenastrum capricornutum. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day at the same location with the same lab sample id (if provided).
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 5 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. For SWAMP data exceedances are counted with the significant effect code SL. SL is defined as the result being significant compared to the negative control based on a statistical test, less than stated the alpha level, AND less than the evaluation threshold. This data set reports a simple pass/fail (Yes/No) code to report toxicity that is equivalent to the SWAMP SL code.
Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
 
Spatial Representation: The samples were collected at Orestimba Creek at Hwy 33.
Temporal Representation: The samples were collected from July 2004 to August 2009.
Environmental Conditions:
QAPP Information: Collected under the Monitoring and Reporting Program Plans for the Westside Water Quality Coalition.
QAPP Information Reference(s):
 
 
DECISION ID
68514
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Diazinon
Final Listing Decision: Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Delist from 303(d) list (TMDL required list)(2016)
Revision Status Original
Reason for Delisting: Applicable WQS attained; reason for recovery unspecified
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under section 4.1 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. Three of 53 available water sample results exceed the evaluation guideline for chronic exposure, and this sample size is sufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of removing this water segment-pollutant combination from the section 303(d) list.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Three of 53 samples exceeded the diazinon evaluation guideline, and this sample size is sufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating according to Table 4.1 of the Listing Policy.
4. Pursuant to section 4.1 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list. The readily available data and information is sufficient to determine, with the power and confidence of the Listing Policy, that this waterbody segment and pollutant combination is attaining the applicable water quality standard for the WARM beneficial use.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 68514, Diazinon
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68575
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 39
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 2 of 39 samples exceed the criterion for Diazinon.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The freshwater chronic criterion value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).
Guideline Reference: Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 7/6/2004 - -8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 68514, Diazinon
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 2795
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Wildlife Habitat
 
Number of Samples: 14
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Diazinon was detected at concentrations exceeding toxicity benchmarks. Of the 14 samples collected at Orestimba Creek, diazinon was detected three times (21% detection frequency), with concentrations of 0.043, 0.046, and 0.276 ug/L. The two lowest detected concentrations were below the CDFG chronic WQC of 0.10 ug/L. The 0.276 ug/L detection exceeded both the chronic and the acute WQC. The three samples with quantifiable diazinon detections were taken from consecutive sampling events at Orestimba Creek on 8/5, 8/12-10 - and 8/19/2002 (Starner et al., 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations shall not exceed those allowable by applicable antidegradation policies (see State Water Resources Control Board Resolution No. 68-16 and 40 CFC section 131.12).

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses. Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the executive Officer. Pesticide concentrations shall not exceed the lowest levels technically and economically achievable. Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of pesticides in excess of the Maximum Contaminant Levels set forth in California Code of Regulations, Title 22, Division 4, Chapter 15.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: CDFG Hazard Assessment Criteria - 0.10 ug/L 4-day average and 0.16 ug/L 1-hour average. (Siepman & Finlayson, 2000; Finlayson, 2004).
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Samples were taken on Orestimba Creek at River Road.
Temporal Representation: Sampling began on July 2, 2002, and continued throughout the summer until September 30, 2002. Each site was sampled once per week.
Environmental Conditions: At each sampling event, temperature, dissolved oxygen (DO), pH, and electrical
conductivity (EC) were measured in situ at each sampling site. DO, EC and temperature were measured. The pH at Orestimba Creek ranged from 7.1 to 7.8.
Measured water temperature ranged from 16 to 25.4 degrees C. DO and EC had ranges of 6.21 to 8.28 mg/L and 641 to 887 uS/cm, respectively.
QAPP Information: Quality Control (QC) for the chemical analysis portion of this study was conducted in accordance with Standard Operating Procedure QAQC001.00 (Segawa, 1995).
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 68514, Diazinon
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 131626
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Westside San Joaquin River Watershed Coalition data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and the results are as follows: 0 of the 3 samples exceeded the evaluation guideline for Diazinon .
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Westside San Joaquin River Watershed Coalition
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The evaluation guideline for diazinon, 1.1 ug/g, is one-tenth of the median lethal concentration for H. azteca(LC50; 11 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 11 ug/g is the geometric mean of LC50 values for diazinon from Ding et al. (2011).
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
 
Spatial Representation: Data were collected from 1 (Station Codes: 541STC519).
Temporal Representation: Data for this waterbody were collected over the date range 2011-09-12 to 2014-03-10
Environmental Conditions:
QAPP Information: Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board  
QAPP Information Reference(s): Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board
 
Line of Evidence (LOE) for Decision ID 68514, Diazinon
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 130825
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Westside San Joaquin River Watershed Coalition data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 1 of 36 samples exceeded the water quality standard for Diazinon.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Westside San Joaquin River Watershed Coalition
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).
Guideline Reference: Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game
 
Spatial Representation: The samples were collected at 1 monitoring site(s) (541STC519)
Temporal Representation: The samples were collected between the dates of 2011-01-03 and 2015-06-09
Environmental Conditions:
QAPP Information: Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board  
QAPP Information Reference(s): Westside San Joaquin River Watershed Coalition Quality Assurance Project Plan For Monitoring Designed for the Irrigated Lands Regulatory Program Central Valley Regional Water Quality Control Board
 
 
DECISION ID
74508
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Dimethoate
Final Listing Decision: Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Delist from 303(d) list (TMDL required list)(2016)
Revision Status Original
Reason for Delisting: Applicable WQS attained; according to new assessment method
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under section 4.1 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. One of 121 water samples exceed the water quality objective. Three of these lines of evidence reflect reassessment of water sample results compared to a more appropriate (higher) evaluation guideline, resulting in only one exceedance.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of removing this water segment-pollutant combination from 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 121 available water sample results exceed the evaluation guideline for WARM, and this does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 74508, Dimethoate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26111
 
Pollutant: Dimethoate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 8
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Twenty-two water samples were collected from Orestimba Creek, under the Irrigated Lands Regulatory Program, between July 2004 and August 2006. Eight of the 22 water samples contained dimethoate at concentrations that exceeded the Evaluation Guideline value of 0.2 ug/L.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Where valid testing has developed 96 hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives (CVRWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The one-tenth of 96-hour LC50 value, tested with dimethoate on the most sensitive species in freshwater (Cyclops strenuus, a copepod crustacean), is 0.2 ug/L.
Guideline Reference: Ecotoxicity database. U.S. Environmental Protection Agency, Office of Pesticide Programs
 
Spatial Representation: Water samples were collected from Orestimba Creek at Kilburn Road and at River Road.
Temporal Representation: Water samples were collected from Orestimba Creek every other week or monthly between July 2004 and August 2006.
Environmental Conditions:
QAPP Information: Data Quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826 ) requirements.
QAPP Information Reference(s): Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
Line of Evidence (LOE) for Decision ID 74508, Dimethoate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26113
 
Pollutant: Dimethoate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 74
Number of Exceedances: 13
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Seventy-four water samples were collected from Orestimba Creek between January 2000 February 2005, as reported in the DPR Surface Water Database.
Thirteen of the 74 water samples exceeded the Evaluation Guideline of 0.2 ug/L.
Data Reference: Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Where valid testing has developed 96 hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives. The one-tenth of 96-hour LC50 value for dimethoate for the most sensitive species in freshwater (Cyclops strenuus, a copepod crustacean), is 0.2 ug/L.
Guideline Reference: ECOTOX database, aquatic data. U. S. Environmental Protection Agency
Guideline Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Spatial Representation: Water samples were collected from Orestimba Creek at River Road.
Temporal Representation: Water samples were collected from Orestimba Creek daily, weekly, or monthly between January 2000 and February 2005.
Environmental Conditions:
QAPP Information: Data Quality: Good. Minimum requirements for the Surface Water Database are:
Name of the sampling agency or organization
Date that each sample was collected
Date of each sample analysis
County where samples were taken
Detailed sampling location information (including latitude and longitude or township/range/section if available), detailed map or description of each sampling site (i.e., address, cross roads, etc.)
Name or description of water body sampled
Name of the active ingredient analyzed for; concentration detected (with unit of measurement), and limit of quantitation
Description of analytical QA/QC plan, or statement that no formal plan exists
Additional optional requirements are included on DPR¿s webpage at http://www.cdpr.ca.gov/docs/emon/surfwtr/caps/req.htm.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74508, Dimethoate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 81119
 
Pollutant: Dimethoate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 74
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Seventy-four water samples were collected from Orestimba Creek, as reported in the DPR Surface Water Database, between January 2000 and February 2005.
None of the 74 water sample results from Orestimba Creek at River Road exceeded the Evaluation Guideline of 4.3 ug/L.
Data Reference: Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
 
SWAMP Data:
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Where valid testing has developed 96-hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives (CVRWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The one-tenth of the 96-hour LC50 value for the most sensitive species, Pteronarcys californica (stonefly), is 4.3 ug/L.
Guideline Reference: Ecotoxicity database. U.S. Environmental Protection Agency, Office of Pesticide Programs
 
Spatial Representation: Water samples were collected from Orestimba Creek at River Road.
Temporal Representation: Water samples were collected from Orestimba Creek daily, weekly or monthly between January 2000 and February 2005.
Environmental Conditions:
QAPP Information: Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
QAPP Information Reference(s): Correspondence between the Department of Pesticide Regulation and Central Valley Regional Water Quality Control Board regarding water quality data for waterbodies in the Central Valley
 
Line of Evidence (LOE) for Decision ID 74508, Dimethoate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 81116
 
Pollutant: Dimethoate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Four water samples were collected from Orestimba Creek under the Pesticide TMDL program, in January to March 2006.
None of the four water sample results from Orestimba Creek at Kilburn Road exceeded the Evaluation Guideline of 4.3 ug/L.
Data Reference: Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
 
SWAMP Data:
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Where valid testing has developed 96-hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives (CVRWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The one-tenth of the 96-hour LC50 value for the most sensitive species, Pteronarcys californica (stonefly), is 4.3 ug/L.
Guideline Reference: Ecotoxicity database. U.S. Environmental Protection Agency, Office of Pesticide Programs
 
Spatial Representation: Water samples were collected from Orestimba Creek at Kilburn Road and at River Road.
Temporal Representation: Water samples were collected from Orestimba Creek on 14 and 15 January 2006, on 28 February 2006 and on 1 March 2006.
Environmental Conditions:
QAPP Information: Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
QAPP Information Reference(s): Quality Assurance Project Plan: Monitoring organophosphorous pesticides in the lower San Joaquin basin. Rancho Cordova, CA: Central Valley RWQCB
QAPP Information Reference(s): Standard operating procedures for pesticides-R5. Rancho Cordova, CA: Central Valley RWQCB
 
Line of Evidence (LOE) for Decision ID 74508, Dimethoate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 81115
 
Pollutant: Dimethoate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Twenty-two water samples were collected from Orestimba Creek, under the Irrigated Lands Regulatory Program, between July 2004 and August 2006.
None of the 17 water sample results from Orestimba Creek at Highway 33 (July 2004 ¿ August 2006) exceeded the Evaluation Guideline of 4.3 ug/L.
None of the 5 water sample results from Orestimba Creek at Kilburn Road (July - September 2004) exceeded the Evaluation Guideline of 4.3 ug/L.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
 
SWAMP Data:
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Where valid testing has developed 96-hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives (CVRWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The one-tenth of the 96-hour LC50 value for the most sensitive species, Pteronarcys californica (stonefly), is 4.3 ug/L.
Guideline Reference: Ecotoxicity database. U.S. Environmental Protection Agency, Office of Pesticide Programs
 
Spatial Representation: Water samples were collected from Orestimba Creek at Kilburn Road and at Highway 33.
Temporal Representation: Water samples were collected from Orestimba Creek every other week or monthly between July 2004 and August 2006.
Environmental Conditions:
QAPP Information: Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
QAPP Information Reference(s): Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
Line of Evidence (LOE) for Decision ID 74508, Dimethoate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68585
 
Pollutant: Dimethoate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: one of 21 samples exceed the evaluation guideline for Dimethoate.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for dimethoate, 4.3 ug/L, is one-tenth of the median lethal concentration (LC50 = 43 ug/L) for Pteronarcys californica (Stonefly); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence was collected at one monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74508, Dimethoate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26115
 
Pollutant: Dimethoate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Four water samples were collected from Orestimba Creek under the Pesticide TMDL program, in January to March 2006. None of the samples exceeded the Evaluation Guideline of 0.2 ug/L.

0 of 2 available concentrations exceeded the criterion (0.2 ug/L).
Data Reference: Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Where valid testing has developed 96 hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives. The one-tenth of 96-hour LC50 value for dimethoate for the most sensitive species in freshwater (Cyclops strenuus, a copepod crustacean), is 0.2 ug/L.
Guideline Reference: ECOTOX database, aquatic data. U. S. Environmental Protection Agency
Guideline Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Spatial Representation: Water samples were collected from Orestimba Creek at Kilburn Road.
Temporal Representation: Water samples were collected from Orestimba Creek on 14 and 15 January 2006, on 28 February 2006, and on 1 March 2006.
Environmental Conditions:
QAPP Information: Data Quality: Good. All sampling, analysis and QA/QC protocols are described in a QAPP prepared for the Pesticide TMDL program sampling.
QAPP Information Reference(s):
 
 
DECISION ID
71787
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Azinphos-methyl (Guthion)
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2008
Impairment from Pollutant or Pollution: Pollution
 
Regional Board Conclusion: 303(d) listing decisions made prior to 2006 were not held in an assessment database. This is a placeholder decision for a CWA section 303(d) Listing made in a previous assessment cycle. The Regional Boards will update this decision when new data and information become available and are assessed.

In addition to the previous determination to list the water body, one new line of evidence was added to the assessment during the 2014 Integrated Report cycle. Zero of zero samples exceed the evaluation guideline for WARM.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 71787, Azinphos-methyl (Guthion)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 4498
 
Pollutant: Azinphos-methyl (Guthion)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 71787, Azinphos-methyl (Guthion)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68548
 
Pollutant: Azinphos-methyl (Guthion)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The available water sample results were all non-detect and they were not assessed because the reporting limits were all above the evaluation guideline and, therefore, could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The National Recommended Water Quality criterion for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
73063
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2011
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess pollutant. One line of evidence is a placeholder for the original listing decision for DDE in fish tissue, but it contains no other data or information. Six of six sample results exceed the water quality objective for the Commercial or recreational collection of fish, shellfish, or organisms beneficial use. The DDE(p,p') analytical method detection limits for six of 21 water sample results were greater than the evaluation guideline; therefore, only 15 of the water sample results could be assessed with the accuracy required by the Listing Policy, and all 15 results exceed the numerical objective for DDE.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Six of six sample results exceed the water quality objective for the Commercial or recreational collection of fish, shellfish, or organisms beneficial use. The DDE(p,p') analytical method detection limits for six of 21 water sample results were greater than the evaluation guideline; therefore, only 15 of the water sample results could be assessed with the accuracy required by the Listing Policy, and all 15 results exceed the numerical objective for DDE. , isms, and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list. The readily available data and information is sufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 73063, DDE (Dichlorodiphenyldichloroethylene)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 23174
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 6
Number of Exceedances: 6
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Six water samples were taken from Orestimba Creek between January, 2006 and August, 2006. All of the available six water samples exceed the California Toxic Rule/USEPA (CTR/USEPA) criteria limit of 0.00059 ug/L for DDE based on a human health carcinogenic risk level of 10-6 for consumption of water and aquatic organisms (4,4-DDE).
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: - Sacramento/San Joaquin River Basin Plan (CVRWQCB, 2007a). Pesticides: Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer.- California Toxics Rule Criteria (USEPA, 2000)Inland Surface Waters based on drinking water and aquatic organism consumption. The criteria are based on human health protection for carcinogenicity at 1-in-a-million risk level (30-day average) for DDE of 0.00059 ug/L.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Orestimba Creek at Highway 33 in Stanislaus County, California.
Temporal Representation: Samples were collected between January, 2006 and August, 2006. Samples were collected at monthly intervals.
Environmental Conditions:
QAPP Information: Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 73063, DDE (Dichlorodiphenyldichloroethylene)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 4499
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Not Recorded
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 73063, DDE (Dichlorodiphenyldichloroethylene)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78896
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 15
Number of Exceedances: 15
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: The DDE(p,p') analytical method detection limits for six of the 21 water samples collected from Orestimba Creek (above Kilburn Road) are greater than the criterion; therefore, only 15 water sample results could be assessed with the accuracy required by the Listing Policy and all 15 results exceed the numerical objective for DDE.
Data Reference: Data for Metals and Nutrients for the City of Anderson, 2006-2008.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Sacramento/San Joaquin River Basin Plan (CVRWQCB, 2007) Pesticides: Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer.- California Toxics Rule Criteria (USEPA, 2000), for Inland Surface Waters based on drinking water and aquatic organism consumption. The criteria are based on human health protection for carcinogenicity at 1-in-a-million risk level (30-day average) with a limit of 0.00059 ug/L for DDE
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Twenty-one water samples were collected from Orestimba Creek (above Kilburn Road) [Orestimba Creek @ Hwy 33 - 541STC519]. Each sample was analyzed for DDE(p,p')
Temporal Representation: The samples were collected between 2/12/2007 and 8/11/2009
Environmental Conditions:
QAPP Information: The data was collected under the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
74031
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2011
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under section 4.1 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. Two of two water sample results exceed the evaluation guideline for the Commercial or recreational collection of fish, shellfish, or organisms beneficial use. Eight of eight water sample results exceed the evaluation guidelines for the Municipal & Domestic Supply and the Warm Freshwater Habitat beneficial uses.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for removing this water segment-pollutant combination from 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. Two of two water sample results exceed the evaluation guideline for the Commercial or recreational collection of fish, shellfish, or organisms beneficial use. Eight of eight water sample results exceed the evaluation guidelines for the Municipal & Domestic Supply and the Warm Freshwater Habitat beneficial uses.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 74031, DDT (Dichlorodiphenyltrichloroethane)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78919
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 8
Number of Exceedances: 8
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: The DDT(p,p') analytical method detection limits for 15 of the 23 water samples collected from Orestimba Creek (above Kilburn Road) are greater than the criterion; therefore, only eight water sample results could be assessed with the accuracy required by the Listing Policy and all eight results exceed the numerical objective for DDT.
Data Reference: Data for Metals and Nutrients for the City of Anderson, 2006-2008.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Sacramento/San Joaquin River Basin Plan (CVRWQCB, 2007) Pesticides: Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer.- California Toxics Rule Criteria (USEPA, 2000), for Inland Surface Waters based on drinking water and aquatic organism consumption. The criteria are based on human health protection for carcinogenicity at 1-in-a-million risk level (30-day average) with a limit of 0.00059 ug/L for DDT
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Twenty-three water samples were collected from Orestimba Creek (above Kilburn Road) [Orestimba Creek @ Hwy 33 - 541STC519]. Each sample was analyzed for DDT(p,p')
Temporal Representation: The samples were collected between 7/11/2006 and 8/11/2009
Environmental Conditions:
QAPP Information: The data was collected under the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74031, DDT (Dichlorodiphenyltrichloroethane)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22890
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Two water samples were taken from Orestimba Creek between July 2006 and August 2006. All of the available two water samples exceeded the California Toxic Rule/USEPA (CTR/USEPA) criteria limit of 0.00059 ug/L for DDT based on a human health carcinogenic risk level of 10-6 for consumption of water and aquatic organisms for DDT.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: - Sacramento/San Joaquin River Basin Plan (CVRWQCB, 2007a). Pesticides: Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer.- California Toxics Rule Criteria (USEPA, 2000)Inland Surface Waters based on drinking water and aquatic organism consumption. The criteria are based on human health protection for carcinogenicity at 1-in-a-million risk level (30-day average) with a limit of less than 0.00059 ug/L for DDT.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Orestimba Creek at Highway 33 in Stanislaus County, California.
Temporal Representation: Samples were collected between July 2006 and August 2006. Samples were collected at monthly intervals.
Environmental Conditions:
QAPP Information: Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74031, DDT (Dichlorodiphenyltrichloroethane)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78921
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 8
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: The DDT(p,p') analytical method detection limits for 15 of the 23 water samples collected from Orestimba Creek (above Kilburn Road) are greater than the criterion; therefore, only eight water sample results could be assessed with the accuracy required by the Listing Policy and all eight results exceed the evaluation guideline for DDT.
Data Reference: Data for Metals and Nutrients for the City of Anderson, 2006-2008.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Sacramento/San Joaquin River Basin Plan (CVRWQCB, 2007) Pesticides: Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer.- California Toxics Rule Criteria (USEPA, 2000), for Inland Surface Waters based on the aquatic life protection from chronic exposure value of 0.001 ug/L for DDT
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Evaluation Guideline:
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Twenty-three water samples were collected from Orestimba Creek (above Kilburn Road) [Orestimba Creek @ Hwy 33 - 541STC519]. Each sample was analyzed for DDT(p,p')
Temporal Representation: The samples were collected between 7/11/2006 and 8/11/2009
Environmental Conditions:
QAPP Information: The data was collected under the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
72642
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Dieldrin
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2011
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under section 4.1, 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. Two of two water sample results exceed the evaluation guideline for the Commercial or recreational collection of fish, shellfish, or organisms beneficial use. None of 21 water sample results exceeded the evaluation guideline for the Warm Freshwater Habitat beneficial use. Three of three water sample results exceeded the evaluation guideline for the Municipal & Domestic Supply beneficial use.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for removing this water segment-pollutant combination from the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Two of two water sample results exceed the evaluation guideline for the Commercial or recreational collection of fish, shellfish, or organisms beneficial use and none of 21 water sample results exceeded the evaluation guideline for the Warm Freshwater Habitat beneficial use and three of three water sample results exceeded the evaluation guideline for the Municipal & Domestic Supply beneficial use, and this sample size is sufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list. The readily available data and information is sufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 72642, Dieldrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22891
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Two (2) water samples were collected from Orestimba Creek, Highway 33, above Kilburn between July 2006 and August 2006 by the Westside San Joaquin River Water Quality Coalition group. All the water samples exceeded the CTR criteria for Dieldrin of 0.00014 ug/L.
Data Reference: National Water Quality Assessment database, San Joaquin and Tulare Basins data
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: - Sacramento/San Joaquin River Basin Plan (CVRWQCB, 2007a)Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer.- California Toxics Rule Criteria (USEPA, 2000):Criteria based on Human Health Protection (30-day average) with a Dieldrin limit of less than 0.00014 ug/L for water and fish consumption.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Two (2) water samples were collected from Orestimba Creek, Highway 33, above Kilburn July 2006 and August 2006 by the Westside San Joaquin River Water Quality Coalition group (Stanislaus County), California.
Temporal Representation: - The Westside San Joaquin River Water Quality Coalition group collected samples between July 2006 and August 2006 at monthly intervals.
Environmental Conditions:
QAPP Information: In accordance with section 6.1.4 of the Listing Policy, data from major monitoring programs in California and Published USGS reports are considered of adequate quality.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 72642, Dieldrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68583
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Dieldrin.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 72642, Dieldrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68584
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 3
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 3 of 3 samples exceed the criterion for Dieldrin.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The criterion for Dieldrin to protect human health from the consumption of water and organisms is 0.00014 ug/L (California Toxics Rule).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
95873
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Indicator Bacteria
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2023
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under section 4.2, one line of evidence is necessary to assess listing status.
Four lines of evidence are available in the administrative record to assess this pollutant. Six of eleven water samples analyzed for fecal coliform exceed the evaluation guideline. Seventy-two of 125 water samples analyzed for E. coli exceed the evaluation guideline.

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 CWA section 303(d) List.
This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Six of eleven water samples exceed the evaluation guideline for fecal coliform and seventy-two of 125 water samples exceed the evaluation guideline for E. coli, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples are needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.1 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 95873, Indicator Bacteria
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68437
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 11
Number of Exceedances: 6
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 6 of 11 samples exceed the criterion for Coliform, Fecal.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: In waters designated for contact recreation (REC-1), the fecal coliform concentration based on a minimum of not less than five samples for any 30-day period shall not exceed a geometric mean of 200/100 ml, nor shall more than ten percent of the total number of samples taken during any 30-day period exceed 400/100 ml. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/11/2008-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 95873, Indicator Bacteria
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68595
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 24
Number of Exceedances: 13
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 13 of 24 samples exceed the criterion for Escherichia coli.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The USEPA recommended objective for single sample maximum allowable density of E. coli in freshwater designated beach areas is 235 MPN/100mL.
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/10/2007-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 95873, Indicator Bacteria
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22913
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 71
Number of Exceedances: 37
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The Central Valley Regional Water Quality Control Board Surface Water Ambient Monitoring Program collected 71 samples from November 2004 to November 2005. Thirty-seven out of 71 samples exceeded the evaluation objective.
Data Reference: Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Evaluation Guideline: The USEPA E. Coli objective of 235/100 mL in any single sample (USEPA 1986).
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected at four locations: Orestimba Creek at Anderson Road, Orestimba creek at Bell Road, Orestimba Creek at Highway 33, and Orestimba Creek at Orestimba Road.
Temporal Representation: Sampling occurred from November 2004 to November 2005.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 95873, Indicator Bacteria
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22912
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 30
Number of Exceedances: 22
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The Westside San Joaquin River Water Quality Coalition collected 30 samples from July 2004 to October 2006. Twenty-two out of the 30 samples collected exceeded the evaluation objective.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Evaluation Guideline: The USEPA E. Coli objective of 235/100 mL in any single sample (USEPA 1986).
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected at Orestimba Creek at Highway 33.
Temporal Representation: Sampling occurred July 2004 to October 2006.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
 
DECISION ID
92848
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Chlorpyrifos
Final Listing Decision: Do Not Delist from 303(d) list (being addressed with action other than TMDL)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (being addressed with action other than TMDL)(2016)
Revision Status Original
Sources: Agriculture
Expected Attainment Date: 2026
Implementation Action Other than TMDL: This water body segment-pollutant combination is being addressed through Basin Plan requirements established under CRWQCB-CVR resolution R5-20140041, and implemented through Board established Waste Discharge Requirements for agricultural discharges. The sources of chlorpyrifos to this segment have been identified as offsite movement of chlorpyrifos from chlorpyrifos applications by the agricultural dischargers regulated by the CRWQCB-CVR WDRs. The Basin Plan identifies numeric water quality objectives for diazinon and chlorpyrifos. The Basin Plan and WDRs require growers to implement management practices through the development and implementation of water quality management plans to meet water quality objectives for chlorpyrifos as soon as possible but no longer than ten years from the date of approval of the Basin Plan Amendment. These management plans are required to be developed and implemented within one year of the Basin Plan Amendment approval. Agricultural management practices to be implemented may include pest management practices, pesticide application practices, vegetation management practices and water management practices, all of which are effective in reducing offsite movement of chlorpyrifos into surface water. The Basin Plan and the Monitoring and Reporting programs in the WDRs require monitoring to determine if adequate reductions are being attained. The Basin Plan and WDRs require management practices to be iteratively improved through updates of the management plans until the water quality objectives are achieved.
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This water body - pollutant combination is being considered for removal from the 303(d) list under sections 2.2 and 4.11 of the Listing Policy. Under section 4.11, 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. The evidence indicates that chlorpyrifos concentrations are not attaining the applicable water quality standards, but existing pollution control requirements, under State authority, are stringent enough to implement applicable water quality standards because the impairment is being addressed by an enforceable regulatory program, other than a TMDL, that is reasonably expected to result in attainment of the water quality standards within a reasonable, specified time frame.
This conclusion is based on the staff findings that:
1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy.
3. Five of 21 available calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion. These exceedances occurred more than once every three years.
4. Four of 21 available 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion. These exceedances occurred more than once every three years.
5. LOE 2794 is a placeholder for a listing decision made for the WARM beneficial use before 2006 and, therefore, does not describe the data used to place this water body segment-pollutant on the section 303(d) list.
6. The sources of chlorpyrifos to this water body segment have been identified as offsite movement of chlorpyrifos from chlorpyrifos applications by the agricultural dischargers, who are regulated under enforceable Waste Discharge Requirements (WDRs).
7. In 2016, the Board adopted Resolution R5-2014-0041 establishing Basin Plan amendments that primarily address the regulation of agricultural pesticide runoff and discharges of diazinon and chlorpyrifos in the Central Valley which are implemented through Board established Waste Discharge Requirements for agricultural dischargers. The amendments established numeric water quality objectives for chlorpyrifos and a control program to ensure that the objectives will be attained within a reasonable, specified time frame.

The Basin Plan and WDRs require growers to implement management practices through the development and implementation of water quality management plans to meet water quality objectives for chlorpyrifos as soon as possible but no longer than ten years from the date of approval of the Basin Plan Amendment. These management plans are required to be developed and implemented within one year of the Basin Plan Amendment approval.
8. Agricultural management practices to be implemented may include pest management practices, pesticide application practices, vegetation management practices and water management practices, all of which are effective in reducing offsite movement of chlorpyrifos into surface water.
9. The Basin Plan and the Monitoring and Reporting programs in the Boards WDRs require monitoring to determine if adequate reductions are being attained. The Basin Plan and WDRs require management practices to be iteratively improved through updates of the management plans until the water quality objectives are attained.
10. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are being met.
 
Regional Board Decision Recommendation: After review of the available data and information described in the lines of evidence associated with this decision, the Regional Water Board determined that this water body and pollutant combination is still impaired and that it should be listed as being addressed by another regulatory program that is reasonably expected to result in attainment of the water quality standard within a reasonable, specified time frame because an alternative State regulatory program is in place which can be reasonably expected to result in attainment of the water quality standard within a reasonable, specified time frame.
 
State Board Review of Regional Board Conclusion and Recommendation: The Basin Plan and WDRs require growers to implement management practices through the development and implementation of water quality management plans to meet water quality objectives for chlorpyrifos as soon as possible but no longer than ten years from the date of approval of the Basin Plan Amendment. These management plans are required to be developed and implemented within one year of the Basin Plan Amendment approval.
8. Agricultural management practices to be implemented may include pest management practices, pesticide application practices, vegetation management practices and water management practices, all of which are effective in reducing offsite movement of chlorpyrifos into surface water.
9. The Basin Plan and the Monitoring and Reporting programs in the Boards WDRs require monitoring to determine if adequate reductions are being attained. The Basin Plan and WDRs require management practices to be iteratively improved through updates of the management plans until the water quality objectives are attained.
10. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are being met.
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92848, Chlorpyrifos
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 2794
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Wildlife Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Chlorpyrifos was detected at concentrations exceeding toxicity benchmarks. Chlorpyrifos was detected in one sample at 0.0705 ug/L, and found at trace concentrations in one additional sample. The detection exceeds both the acute and chronic CDFG WQC (Starner et al., 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations shall not exceed those allowable by applicable antidegradation policies (see State Water Resources Control Board Resolution No. 68-16 and 40 CFR section 131.12).

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses. Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the executive Officer. Pesticide concentrations shall not exceed the lowest levels technically and economically achievable. Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of pesticides in excess of the Maximum Contaminant Levels set forth in California Code of Regulations, Title 22, Division 4, Chapter 15.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: CDFG Hazard Assessment Criteria - 14 ng/L 4-day average and 25 ng/L 1-hour average.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Samples were taken on Orestimba Creek at River Road.
Temporal Representation: Sampling began on July 2, 2002, and continued throughout the summer until September 30, 2002. Each site was sampled once per week.
Environmental Conditions: At each sampling event, temperature, dissolved oxygen (DO), pH, and electrical
conductivity (EC) were measured in situ at each sampling site. DO, EC and temperature were measured. The pH at Orestimba Creek ranged from 7.1 to 7.8.
Measured water temperature ranged from 16 to 25.4 degrees C. DO and EC had ranges of 6.21 to 8.28 mg/L and 641 to 887 uS/cm, respectively.
QAPP Information: Quality Control (QC) for the chemical analysis portion of this study was conducted in accordance with Standard Operating Procedure QAQC001.00 (Segawa, 1995).
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 92848, Chlorpyrifos
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68564
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 5
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 5 of 21 samples exceed the criterion for Chlorpyrifos.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (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 (with minor corrections to significant figures as described in Beaulaurier et al., 2005).
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91611
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Aldicarb
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the ten samples exceed each of the MUN and WARM water Evaluation Guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of ten samples exceed each of the MUN and WARM water Evaluation Guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91611, Aldicarb
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68534
 
Pollutant: Aldicarb
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Aldicarb.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for aldicarb, 6.33 ug/L, is one-tenth of the median lethal concentration (LC50 = 63.3 ug/L) for Lepomis macrochirus (Bluegill sunfish); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 91611, Aldicarb
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68535
 
Pollutant: Aldicarb
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Aldicarb.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Department of Public Health archived advisory level for aldicarb is 7 ug/L.
Guideline Reference: CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91719
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Aldrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the zero samples exceed the MUN, zero of the 21 samples exceed the WARM water Criteria/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 CWA 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. Zero of zero samples exceed the MUN, zero of 21 samples exceed the WARM water Criteria/Objective, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91719, Aldrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68536
 
Pollutant: Aldrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Aldrin.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The criterion maximum concentration to protect aquatic life in freshwater for aldrin is 1.5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 91719, Aldrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68537
 
Pollutant: Aldrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Aldrin.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The CTR objective for aldrin to protect human health from the consumption of water and organisms is 0.00013 ug/L.
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
94902
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Ammonia as N, Total
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 27 samples exceed the calculated CMC Evaluation Guideline.

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 CWA 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. Zero of 27 samples exceeded the calculated CMC Evaluation Guideline, and this sample size does not exceed the allowable frequency listed in Table 3.11 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 94902, Ammonia as N, Total
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 79020
 
Pollutant: Ammonia as N, Total
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 27
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Twenty-seven water samples collected from Orestimba Creek (above Kilburn Road) Westside Water Quality Coalition were analyzed for ammonia, pH and temperature. None of the 27 samples exceeded the calculated ammonia CMC values.
Data Reference: Data for Various Pollutants in Southern San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data:
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Per the National Recommended Water Quality Criteria (USEPA 2006): The 1-hour average concentration (acute criterion or CMC) of total ammonia nitrogen (in mg N/L) for freshwater where salmonid fish are present, which is not to be exceeded more than once every three years on average, is calculated using the following equation: CMC=0.275/(1+10^(7.204 - pH)) + 39.0/(1+10^(pH - 7.204)).
Guideline Reference: Data for Various Pollutants in South San Joaquin Irrigation District, 2004-2008.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: The 27 water samples were collected from Orestimba Creek (above Kilburn Road) at one monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Twenty-seven water samples were collected from Orestimba Creek (above Kilburn Road) between 7/11/2006 and 2/18/2009
Environmental Conditions:
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
76902
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Arsenic
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of 26 samples exceed the criteria.

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 CWA 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. Zero of 26 samples exceed the criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 76902, Arsenic
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68544
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 26
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 26 samples exceed the criterion for Arsenic.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 0.150 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/9/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 76902, Arsenic
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68545
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 26
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 26 samples exceed the criterion for Arsenic.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for arsenic is 0.010 mg/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/9/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
85992
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Atrazine
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of 21 samples exceed the criteria.

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 CWA 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. Zero of 21 samples exceed the criteria and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 85992, Atrazine
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68546
 
Pollutant: Atrazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Atrazine.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Atrazine, 43 ug/L, is a an EC50 for Lemna gibba (duckweed); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 85992, Atrazine
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68547
 
Pollutant: Atrazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Atrazine.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for atrazine is 1 ug/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
85994
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Bifenthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 0 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 0 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 85994, Bifenthrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68555
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Bifenthrin. Eight samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." Aquatic life should not be affected unacceptably if the 4-day average concentration of Bifenthrin, 0.0006 ug/L, is not exceeded more than once every three years on the average (UC Davis Aquatic Life Criterion).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
86064
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Cadmium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of 26 samples exceed the 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 CWA 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. Zero of 26 samples exceed the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 86064, Cadmium
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68556
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 26
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 26 sample dates exceed the criterion for Cadmium.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for cadmium is 5 ug/L.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/9/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
86066
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Carbaryl
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 10 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 10 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 86066, Carbaryl
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68557
 
Pollutant: Carbaryl
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Carbaryl.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The USEPA recommended water quality criterion for freshwater aquatic life for carbaryl is 2.1 µg/L.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91877
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Carbofuran
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 10 samples exceed the MUN water Criteria/Objective, zero of the 10 samples exceed the WARM water evaluation guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 10 samples exceed the MUN water Criteria/Objective, zero of 10 samples exceed the WARM water evaluation guideline, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91877, Carbofuran
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68559
 
Pollutant: Carbofuran
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Carbofuran.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for Carbofuran is 18 ug/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 91877, Carbofuran
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68558
 
Pollutant: Carbofuran
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Carbofuran.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The freshwater criterion maximum concentration for carbofuran is 0.5 µg/L (DFG 92-3, 1992).
Guideline Reference: Hazard Assessment of the Insecticide Carbofuran to Aquatic Organisms in the Sacramento River System
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
86161
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Copper
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of 26 samples exceed the 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 CWA 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. Zero of 26 samples exceed the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 86161, Copper
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68565
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 26
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 26 samples exceed the criterion for Copper.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California secondary maximum contaminant level for copper is 1.0 mg/L.
Objective/Criterion Reference: Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/9/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 86161, Copper
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68566
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed AgWaiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 5 samples exceed the criterion for Copper.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The chromium criterion in freshwater is hardness-dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness-dependent formula for metals criteria.
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/10/2009-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91924
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Cyanazine
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed the Evaluation Guideline.

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 CWA 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. Zero of 21 samples exceeded the Evaluation Guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91924, Cyanazine
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68567
 
Pollutant: Cyanazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Cyanazine.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The EC50 for Navicula pelliculosa (freshwater diatom) for cyanazine is 4.8 ug/L (USEPA Office of Pesticide Programs Ecotoxicity database).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
86163
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Cyfluthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 0 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 0 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 86163, Cyfluthrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68568
 
Pollutant: Cyfluthrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Cyfluthrin, total. Eight samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." Aquatic life should not be affected unacceptably if the 4-day average concentration of Cyfluthrin, 0.00005 ug/L, is not exceeded more than once every three years on the average (UC Davis Aquatic Life Criterion).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
99990
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Cyhalothrin, Lambda
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 0 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 0 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 99990, Cyhalothrin, Lambda
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68573
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Cyhalothrin, lambda. Eight samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." Aquatic life should not be affected unacceptably if the 4-day average concentration of Cyhalothrin, 0.0005 ug/L, is not exceeded more than once every three years on the average (UC Davis Aquatic Life Criterion).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
86196
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Cypermethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 0 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 0 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 86196, Cypermethrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68574
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Cypermethrin, total. Eight samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." Aquatic life should not be affected unacceptably if the 4-day average concentration of Cypermethrin, 0.0002 ug/L, or the 1-hour average concentration, 0.001 ug/L, is not exceeded more than once every three years on the average (UC Davis Aquatic Life Criterion).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
74362
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. One of the two samples exceed the COMM, one of the one samples exceed the MUN 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 the two samples exceed the COMM, one of the one samples exceed the MUN water quality objective, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 74362, DDD (Dichlorodiphenyldichloroethane)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78844
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: The DDD(p,p') analytical method detection limits for 22 of the 23 water samples collected from Orestimba Creek (above Kilburn Road) are greater than the criterion; therefore, only one water sample result could be assessed with the accuracy required by the Listing Policy.
Data Reference: Data for Metals and Nutrients for the City of Anderson, 2006-2008.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Sacramento/San Joaquin River Basin Plan (CVRWQCB, 2007) Pesticides: Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer.- California Toxics Rule Criteria (USEPA, 2000), for Inland Surface Waters based on drinking water and aquatic organism consumption. The criteria are based on human health protection for carcinogenicity at 1-in-a-million risk level (30-day average) with a limit of 0.00083 ug/L for DDD
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Twenty-three water samples were collected from Orestimba Creek (above Kilburn Road) [Orestimba Creek @ Hwy 33 - 541STC519]. Each sample was analyzed for DDD(p,p')
Temporal Representation: The samples were collected between 7/11/2006 and 8/11/2009
Environmental Conditions:
QAPP Information: The data was collected under the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74362, DDD (Dichlorodiphenyldichloroethane)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 23173
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Two water samples were taken from Orestimba Creek between July 2006 and August 2006. One of the available two water samples exceeded the California Toxic Rule/USEPA (CTR/USEPA) criteria limit for DDD of 0.00083 ug/L based on a human health carcinogenic risk level of 10-6 for consumption of water and aquatic organisms.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: - Sacramento/San Joaquin River Basin Plan (CVRWQCB, 2007a). Pesticides: Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer.- California Toxics Rule Criteria (USEPA, 2000)Inland Surface Waters based on drinking water and aquatic organism consumption. The criteria are based on human health protection for carcinogenicity at 1-in-a-million risk level (30-day average) for DDD of 0.00083 ug/L.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Orestimba Creek at Highway 33 in Stanislaus County, California.
Temporal Representation: Samples were collected between July 2006 and August 2006. Samples were collected at monthly intervals.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
 
DECISION ID
74506
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Dacthal
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. None of 131 water samples exceed the Evaluation Guideline for Dacthal (DCPA), which is based on the U.S. Environmental Protection Agency National Ambient Water Quality Criteria value of 70 µg/L, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 74506, Dacthal
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26109
 
Pollutant: Dacthal
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 131
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of 131 water samples collected from Colusa Basin Drain by the United States Geological Survey, under the National Water Information System program, between November 1996 and April 1998, exceeded the Evaluation Guideline (USEPA National Ambient Water Quality Criterion for dacthal (DCPA)) of 70 ug/L.
Data Reference: National Water Quality Assessment database, Sacramento Study Unit data
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CRWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: USEPA National Ambient Water Quality Criterion for dacthal (DCPA) of 70 ug/L.
Guideline Reference: 2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
 
Spatial Representation: Water samples were collected from Orestimba Creek at River Road near Crows Landing.
Temporal Representation: Water samples were collected from January 2000 to September 2005 at variable intervals (e.g. hourly, daily, weekly, twice per month).
Environmental Conditions:
QAPP Information: Data Quality: Good: U.S. Geological Survey, variously dated, National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A1-A9, available online at http://pubs.water.usgs.gov/twri9A
QAPP Information Reference(s): National field manual for the collection of water quality data. Reston, VA. U.S. Geological Survey. Office of Water Quality
QAPP Information Reference(s): Field measurements: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A6. In United States Geological Survey (USGS). Variously dated. National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A1-A9, available online at http://pubs.water.usgs.gov/twri9A.
 
 
DECISION ID
86495
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Dichlorvos
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 13 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 13 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 86495, Dichlorvos
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68576
 
Pollutant: Dichlorvos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for Dichlorvos.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Dichlorvos, 7.2 ug/L, is the maximum acceptable toxicicant concentration (MATC) for Oncorhyncus mykiss (Rainbow trout); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/11/2008-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91978
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Dicofol
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed the Evaluation Guideline.

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 CWA 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. Zero of 21 samples exceeded the Evaluation Guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91978, Dicofol
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68582
 
Pollutant: Dicofol
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Dicofol.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Dicofol, 5.9 ug/L, is the maximum acceptable toxicicant concentration (MATC) for Oncorhyncus mykiss (Rainbow trout); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
75836
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Disulfoton
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 193 samples exceed each of the WARM water Evaluation Guideline.

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 CWA 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. Zero of 193 samples exceeded each of the WARM water Evaluation Guideline, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 75836, Disulfoton
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26171
 
Pollutant: Disulfoton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 17
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Forty-one water samples were collected from Orestimba Creek, under the Irrigated Lands Regulatory Program, between July 2004 and August 2006. Zero of the 7 water samples contained disulfoton at concentrations that exceed the Evaluation Guideline of 0.05 ug/L. Twenty-four of the samples had quantitation limits greater than the Evaluation Guideline value and, therefore, according to Section 6.1.5.5 of the Listing Policy these sample results were not included in this assessment.
Data Reference: Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
  Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: USEPA National Ambient Water Quality Disulfoton Criterion for freshwater aquatic life protection, maximum concentration of 0.05 ug/L.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Water samples were collected from Orestimba Creek at Kilburn Road, Highway 33, and River Road.
Temporal Representation: Water samples were collected from Orestimba Creek at Kilburn Road on: July 15 and 29, 2004; August 12 and 26, 2004; and September 9, 2004.
Water samples were collected from Orestimba Creek at Highway 33 on: July 6, 2004; August 10, 2004; December 29, 2004; monthly between February 16 and August 9, 2005; January 3, 2006; and monthly between March 14 and August 9, 2006.
Water samples were collected from Orestimba Creek at River Road on: July 6, 2004; August 10, 2004; December 29, 2004; monthly between February 16 and August 9, 2005; January 3, 2006; and monthly between March 14 and August 9, 2006.
Environmental Conditions:
QAPP Information: Data Quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826 ) requirements.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 75836, Disulfoton
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68586
 
Pollutant: Disulfoton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Disulfoton.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The USEPA National Recommended Water Quality criterion for disulfoton in freshwater (0.05 ug/L) is an aquatic life maximum (instantaneous) level.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 75836, Disulfoton
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26169
 
Pollutant: Disulfoton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Four water samples were collected from Orestimba Creek, under the Pesticide TMDL program, between January and March 2006. Zero of the 4 water samples contained disulfoton at a concentration that exceeds the Evaluation Guideline of 0.05 ug/L.
Data Reference: Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: USEPA National Ambient Water Quality disulfoton criterion for freshwater aquatic life protection, maximum concentration of 0.05 ug/L.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Water samples were collected from Orestimba Creek at Kilburn Road.
Temporal Representation: Water samples were collected from Orestimba Creek on 14 and 15 January 2006, 28 February 2006, and 1 March 2006.
Environmental Conditions:
QAPP Information: Data Quality: Good. All sampling, analysis and QA/QC protocols are described in a QAPP (Calanchini et al., 2006).
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 75836, Disulfoton
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26167
 
Pollutant: Disulfoton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 151
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: One hundred fifty one water samples were collected from Orestimba Creek at River Road and analyzed for disulfoton. None of the 151 water samples contained disulfoton at concentrations that exceed the Evaluation Guideline of 0.05 ug/L.
Data Reference: Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007). All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: USEPA National Ambient Water Quality disulfoton criterion for freshwater aquatic life protection, maximum concentration of 0.05 ug/L.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Samples were collected from Orestimba Creek at River Road.
Temporal Representation: Water samples were collected from Orestimba Creek between January 6, 2000 and September 7, 2005, as reported in the DPR Surface Water Database, at various intervals, including daily, twice weekly, weekly, twice monthly, monthly, every two months, and every 3 to 6 months.
Environmental Conditions:
QAPP Information: Data quality: Good. Minimum requirements for the Surface Water Database are:
Name of the sampling agency or organization
Date that each sample was collected
Date of each sample analysis
County where samples were taken
Detailed sampling location information (including latitude and longitude or township/range/section if available), detailed map or description of each sampling site (i.e., address, cross roads, etc.)
Name or description of water body sampled
Name of the active ingredient analyzed for; concentration detected (with unit of measurement), and limit of quantitation
Description of analytical QA/QC plan, or statement that no formal plan exists
Additional optional requirements are included on DPR¿s webpage at http://www.cdpr.ca.gov/docs/emon/surfwtr/caps/req.htm
QAPP Information Reference(s): Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
 
 
DECISION ID
92083
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: EPTC (Eptam, s-ethyl dipropylthiocarbamate)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 42 samples exceed the WARM water Evaluation Guideline.

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 CWA 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. Zero of the 42 samples exceed the WARM water Evaluation Guideline, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92083, EPTC (Eptam, s-ethyl dipropylthiocarbamate)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68594
 
Pollutant: EPTC (Eptam, s-ethyl dipropylthiocarbamate)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for EPTC.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for EPTC, 1,000 ug/L, is the maximum acceptable toxicicant concentration (MATC) for Daphnia magna (Water flea); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/11/2008-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 92083, EPTC (Eptam, s-ethyl dipropylthiocarbamate)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78688
 
Pollutant: EPTC (Eptam, s-ethyl dipropylthiocarbamate)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 28
Number of Exceedances: 0
 
Data and Information Type: Physical/chemical data extrapolated from upstream or downstream waterbody
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 28 samples exceed the criterion for EPTC.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: According to the USEPA Office of Pesticide Programs Ecotoxicity database, the freshwater aquatic life MATC for EPTC is 1000 ug/L.
Guideline Reference: Data for Various Pollutants in Merced Irrigation District, 2005-2008.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 7/6/2004-8/11/2009. The results for samples collected on the same date were averaged before they were assessed.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
73783
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Endosulfan sulfate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 13 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 13 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 73783, Endosulfan sulfate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78687
 
Pollutant: Endosulfan sulfate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for Endosulfan sulfate.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Endosulfan Sulfate criterion to protect human health for waters that include the designated use of MUN is 110 ug/L (California Toxics Rule, 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: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/11/2008-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92030
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Endrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed each of the MUN and WARM 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 CWA 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. Zero of 21 samples exceeded each of the MUN and WARM water quality objectives and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92030, Endrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68592
 
Pollutant: Endrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Endrin.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L. (California Toxics Rule, 2000)
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 92030, Endrin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68593
 
Pollutant: Endrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Endrin.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Endrin criterion for the protection of human health from the consumption of water and organisms is 0.76 ug/L. (California Toxics Rule, 2000)
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
86496
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Esfenvalerate/Fenvalerate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 8 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 8 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 86496, Esfenvalerate/Fenvalerate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68436
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Esfenvalerate/Fenvalerate.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for fenvalerate, 0.113 ug/L, is one-tenth the LC50 (1.13 ug/L) for Pimephales promelas (Fathead minnow); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
78782
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Glyphosate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of 7 samples exceed the criteria.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 7 samples exceed the criteria and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78782, Glyphosate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68439
 
Pollutant: Glyphosate
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: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Glyphosate.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for Glyphosate is 700 ug/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 78782, Glyphosate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68438
 
Pollutant: Glyphosate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Glyphosate.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for glyphosate, 5,500 ug/L, is one-tenth of the median lethal concentration (LC50 = 55,000 ug/L) for Chironimus plumosus (Midge). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
77524
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Heptachlor
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the zero samples exceed each of the MUN and WARM water Criteria/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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of zero samples exceed each of the MUN and WARM water Criteria/Objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 77524, Heptachlor
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68440
 
Pollutant: Heptachlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 77524, Heptachlor
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68446
 
Pollutant: Heptachlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The CTR objective for Heptachlor to protect human health from the consumption of water and organisms is 0.00021 ug/L.
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92284
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Heptachlor epoxide
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the zero samples exceed each of the MUN and WARM water Criteria/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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of zero samples exceed each of the MUN and WARM water Criteria/Objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92284, Heptachlor epoxide
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68447
 
Pollutant: Heptachlor epoxide
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of07 samples exceed the criterion for Heptachlor epoxide.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Heptachlor Epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 92284, Heptachlor epoxide
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68448
 
Pollutant: Heptachlor epoxide
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of07 samples exceed the criterion for Heptachlor epoxide.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The CTR objective for Heptachlor epoxide to protect human health from the consumption of water and organisms is 0.0001 ug/L.
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
76898
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Lead
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 5 samples exceed the 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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 5 samples exceed the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 76898, Lead
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68449
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed AgWaiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 5 samples exceed the criterion for Lead.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The chromium criterion in freshwater is hardness-dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness-dependent formula for metals criteria.
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/10/2009-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91499
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 42 samples exceed each of the MUN and WARM 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 CWA 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. Zero of 42 samples exceeded each of the MUN and WARM water quality objectives and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91499, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68450
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for HCH, gamma.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The gamma-HCH (Lindane) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 91499, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78692
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for HCH, gamma.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The gamma-BHC (Lindane) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L (California Toxics Rule, 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: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 91499, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78691
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for HCH, gamma.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The BHC, gamma(Lindane) criteria for the protection of human health from the consumption of water and organisms is 0.019 ug/L (California Toxics Rule, 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: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 91499, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68451
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for HCH, gamma.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for HCH, gamma (Lindane) is 0.2 ug/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91500
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Linuron
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed the Evaluation Guideline.

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 CWA 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. Zero of 21 samples exceeded the Evaluation Guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91500, Linuron
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68462
 
Pollutant: Linuron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Linuron.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Linuro, 13.7 ug/L, is the EC50 for Navicula pelliculosa (freshwater diatom). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
76899
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Malathion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. One of 1 sample exceeds the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of 1 sample exceeds the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 76899, Malathion
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68463
 
Pollutant: Malathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Malathion.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." Aquatic life should not be affected unacceptably if the 4-day average concentration of Malathion, 0.028 ug/L, is not exceeded more than once every three years on the average (UC Davis Aquatic Life Criterion).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92395
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Methidathion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed the Evaluation Guideline.

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 CWA 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. Zero of 21 samples exceeded the Evaluation Guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92395, Methidathion
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68464
 
Pollutant: Methidathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Methidathion.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Methidathion, 0.86 ug/L, is the maximum acceptable toxicicant concentration (MATC) for Daphina magna (Water flea); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92412
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Methiocarb
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the ten samples exceed the Evaluation Guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of ten samples exceeded Evaluation Guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92412, Methiocarb
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68465
 
Pollutant: Methiocarb
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Methiocarb.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for methiocarb, 43.6 ug/L, is one-tenth of the median lethal concentration (LC50 = 436 ug/L) for Oncorhyncus mykiss (Rainbow trout); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
75525
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Methomyl
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. One of 17 samples exceed the guideline.

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 CWA 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 17 samples exceed the guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 75525, Methomyl
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26173
 
Pollutant: Methomyl
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Seven water samples were collected from Orestimba Creek, under the Irrigated Lands Regulatory Program, monthly or twice per month between July 2004 and August 2006. One of the 7 water samples contained methomyl at concentrations that exceed the Evaluation Guideline for the 4-day average concentration (0.52 ug/L). Zero of the 7 water samples contained methomyl at concentrations that exceed the Evaluation Guideline for the 1-hour maximum concentration (5.5 ug/L).
Data Reference: Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
  Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: California Department of Fish and Game Hazard Assessment methomyl 4-day average concentration (0.52 ug/L) and 1-hour maximum concentration (5.5 ug/L).
Guideline Reference: Hazard Assessment of the Insecticide Methomyl to Aquatic Organisms in the San Joaquin River System - Administrative Report 96-6
 
Spatial Representation: Water samples were collected from Orestimba Creek at Kilburn Road and River Road.
Temporal Representation: Water samples were collected from Orestimba Creek monthly or twice per month between July 2004 and August 2006.
Environmental Conditions:
QAPP Information: Data Quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826 ) requirements.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 75525, Methomyl
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68475
 
Pollutant: Methomyl
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Methomyl.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Methomyl, 0.5 ug/L, is a 4-day average value; CDFG, 1996.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
75867
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Methoxychlor
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed each of the MUN and WARM 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 CWA 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. Zero of 21 samples exceeded each of the MUN and WARM water quality objectives and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 75867, Methoxychlor
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68476
 
Pollutant: Methoxychlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Methoxychlor.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 75867, Methoxychlor
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68477
 
Pollutant: Methoxychlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Methoxychlor.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for Methoxychlor, 30 ug/L, is incorporated by reference into the (Water Quality Control Plan, Central Valley Region, Sacramento and San Joaquin Basins).
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
75868
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Methyl Parathion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed the MUN, zero of the zero samples exceed the WARM water Evaluation Guideline.

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 CWA 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. Zero of the 21 samples exceed the MUN, zero of the zero samples exceed the WARM water Evaluation Guideline, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 75868, Methyl Parathion
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68478
 
Pollutant: Methyl Parathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Parathion, Methyl.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The California Department of Fish and Game instantaneous aquatic life criterion for Methyl Parathion is 0.08 ug/L.
Guideline Reference: Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System. California Department of Fish and Game. Environmental Services Division. Administrative Report 92-1
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 75868, Methyl Parathion
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68479
 
Pollutant: Methyl Parathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Parathion, Methyl.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The NAS health advisory level for methyl parathion is 30 µg/L.
Guideline Reference: National Academy of Sciences - Volume I Drinking Water and Health
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92397
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Molinate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the eight samples exceed the MUN water Criteria/Objective, zero of the eight samples exceed the WARM water evaluation guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of eight samples exceed the MUN water Criteria/Objective, zero of eight samples exceed the WARM water evaluation guideline, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92397, Molinate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68492
 
Pollutant: Molinate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Molinate.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for Molinate is 20 ug/L .
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 92397, Molinate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68491
 
Pollutant: Molinate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Molinate.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Molinate, 600 ug/L, the maximum acceptable toxicicant concentration (MATC) for Daphnia magna (Water flea). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
77694
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Nickel
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of 25 samples exceed the 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 CWA 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. Zero of 25 samples exceed the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 77694, Nickel
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68494
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed AgWaiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 5 samples exceed the criterion for Nickel.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The chromium criterion in freshwater is hardness-dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness-dependent formula for metals criteria.
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/10/2009-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 77694, Nickel
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68493
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 25
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 25 samples exceed the criterion for Nickel.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for nickel is 0.1 mg/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/9/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
77695
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. One of 10 samples exceed the 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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of 10 samples exceed the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 77695, Nitrate/Nitrite (Nitrite + Nitrate as N)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68495
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 10
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 1 of 10 samples exceed the criterion for Nitrate/Nitrite as N.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for nitrate + nitrite (as N) is 10.0 mg/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 4/8/2008-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
77696
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Nitrogen, Nitrate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. One of 14 samples exceed the 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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of 14 samples exceed the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 77696, Nitrogen, Nitrate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68496
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 14
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 1 of 14 samples exceed the criterion for Nitrate as N.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for nitrate (NO3 as N) is 10.0 mg/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/9/2007-3/11/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92414
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Nitrogen, Nitrite
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the 14 samples exceed the Criteria/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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 14 samples exceeded Criteria/Objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92414, Nitrogen, Nitrite
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68452
 
Pollutant: Nitrogen, Nitrite
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 14
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 14 samples exceed the criterion for Nitrite as N.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for nitrite (as N) is 1 mg/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/9/2007-3/11/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92415
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Oxamyl (Vydate)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the 12 samples exceed the Criteria/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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 12 samples exceeded Criteria/Objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92415, Oxamyl (Vydate)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78693
 
Pollutant: Oxamyl (Vydate)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Oxamyl.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: "Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: Waters designated for use as domestic or
municipal supply (MUN) shall not contain concentrations of pesticides in excess of the Maximum Contaminant Levels set forth in California Code of Regulations, Title 22, Division 4, Chapter 15. The California Maximum Contaminant Level for Oxamyl incorporated by reference in the Water Quality Control Plan is 50 ug/L. "
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 7/11/2006-2/18/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
76814
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Paraquat
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 9 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 9 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 76814, Paraquat
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78694
 
Pollutant: Paraquat
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Paraquat.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The evaluation guideline for paraquat is the median effective concentration (EC50) 1200 ug/L.  (USEPA Office of Pesticide Programs Ecotoxicity database).
Guideline Reference: Data for Various Pollutants in Merced Irrigation District, 2005-2008.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 7/11/2006-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92473
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Parathion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 13 samples exceed the MUN, zero of the zero samples exceed the WARM water Evaluation Guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 13 samples exceed the MUN, zero of zero samples exceed the WARM water Evaluation Guideline, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92473, Parathion
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68455
 
Pollutant: Parathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Parathion, Ethyl.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The USEPA national ambient water quality chronic criterion (4-hour maximum) for parathion, is 0.013 µg/L, is for freshwater aquatic life.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/11/2008-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 92473, Parathion
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68454
 
Pollutant: Parathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for Parathion, Ethyl.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The NAS health advisory level for parathion or ethyl parathion is 30 µg/L.
Guideline Reference: National Academy of Sciences - Volume I Drinking Water and Health
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/11/2008-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
76815
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Pendimethalin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of 41 samples exceed the guideline.

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 CWA 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. Zero of 41 samples exceed the guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 76815, Pendimethalin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68456
 
Pollutant: Pendimethalin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for Pendimethalin.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Pendimethalin, 5.4 ug/L, is the EC50 for Selenastrun capricornutum (Green algae). USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/11/2008-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 76815, Pendimethalin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78695
 
Pollutant: Pendimethalin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 28
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 28 samples exceed the criterion for pendimethalin.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The evaluation guideline for pendimethalin is the EC50 5.4 ug/L.  (USEPA Office of Pesticide Programs Ecotoxicity database).
Guideline Reference: Data for Various Pollutants in Merced Irrigation District, 2005-2008.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 7/6/2004-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
86497
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Permethrin, total
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 0 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 0 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 86497, Permethrin, total
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68466
 
Pollutant: Permethrin, total
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Permethrin, Total. Eight samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." Aquatic life should not be affected unacceptably if the 4-day average concentration of Permethrin, 0.0002 ug/L, is not exceeded more than once every three years on the average (UC Davis Aquatic Life Criterion).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92529
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Phorate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed the Evaluation Guideline.

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 CWA 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. Zero of 21 samples exceeded the Evaluation Guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92529, Phorate
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68467
 
Pollutant: Phorate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Phorate.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for phorate, 0.2 ug/L, is one-tenth of the median lethal concentration (LC50 = 2.0 ug/L) for Lepomis macrochirus (Bluegill sunfish). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
99991
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Phosmet
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed the Evaluation Guideline.

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 CWA 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. Zero of 21 samples exceeded the Evaluation Guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 99991, Phosmet
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68468
 
Pollutant: Phosmet
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Phosmet.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Phosmet, 5.6 ug/L, is the EC50 for Daphnia magna (Water flea). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
75204
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Prometryn
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. One of the samples exceeds 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 54 samples exceeded the narrative toxicity objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 75204, Prometryn
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26175
 
Pollutant: Prometryn
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 52
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Fifty-two water samples were collected from Orestimba Creek at River Road from January 2000 through September 2002 representing 52 concentrations.
Data Reference: Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
  Correspondence between the Department of Pesticide Regulation and Central Valley Regional Water Quality Control Board regarding water quality data for waterbodies in the Central Valley
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007).All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The EC50 for the most sensitive species freshwater species (Navicula pelliculosa, a freshwater diatom) is 1 ug/L (U.S. EPA, 2000).
Guideline Reference: Ecotoxicity database. U.S. Environmental Protection Agency, Office of Pesticide Programs
 
Spatial Representation: Samples were collected from Orestimba Creek at River Road.
Temporal Representation: Samples were collected at variable intervals (biweekly, weekly, monthly) from January 2000 through September 2002.
Environmental Conditions:
QAPP Information: Data quality: Good. Minimum requirements for the CDPR Surface Water Database are: Name of the sampling agency or organization, Date that each sample was collected, Date of each sample analysis, County where samples were taken, Detailed sampling location information (including latitude and longitude or township/range/section if available), detailed map or description of each sampling site (i.e., address, cross roads, etc.), Name or description of water body sampled, Name of the active ingredient analyzed for; concentration detected (with unit of measurement), and limit of quantitation, Description of analytical QA/QC plan, or statement that no formal plan exists. Additional optional requirements are included on DPR's webpage at http://www.cdpr.ca.gov/docs/emon/surfwtr/caps/req.htm
QAPP Information Reference(s): Standard Operating Procedure for Conducting Surface Water Monitoring for Pesticides
 
Line of Evidence (LOE) for Decision ID 75204, Prometryn
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26176
 
Pollutant: Prometryn
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Four water samples (two sets of duplicate samples, representing two daily-averaged water sample results for prometryn) were collected from Orestimba Creek at River Road on January 3, 2006 and April 4, 2006, under the Irrigated Lands Regulatory Program.
Data Reference: Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
  Correspondence between the Department of Pesticide Regulation and Central Valley Regional Water Quality Control Board regarding water quality data for waterbodies in the Central Valley
  Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007).All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The EC50 for the most sensitive species freshwater species (Navicula pelliculosa, a freshwater diatom) is 1 ug/L (U.S. EPA, 2000).
Guideline Reference: Ecotoxicity database. U.S. Environmental Protection Agency, Office of Pesticide Programs
 
Spatial Representation: Water samples were collected from Orestimba Creek at River Road.
Temporal Representation: Two (duplicate) water samples were collected from Orestimba Creek at River Road on January 3, 2006 and on April 4, 2006.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826 ) requirements.
QAPP Information Reference(s): Standard Operating Procedure for Conducting Surface Water Monitoring for Pesticides
QAPP Information Reference(s): Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
 
DECISION ID
75973
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Propargite
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.2 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. Zero of the samples exceed the Evaluation Guideline for the narrative toxicity 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. Zero of 147 samples exceeded the Evaluation Guideline for propargite 6 ug/L, which is one-tenth of the LC50 for the most-sensitive freshwater species, Cyprinodon variegatus, Sheepshead minnow). Therefore, none of the 147 sample results exceed the narrative toxicity objective, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 75973, Propargite
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26178
 
Pollutant: Propargite
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 115
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: One hundred-fifteen water samples were collected from Orestimba Creek at River Road and analyzed for propargite. None of the 115 water samples contained propargite at concentrations that exceed the Evaluation Guideline of 6 ug/L.
Data Reference: Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Where valid testing has developed 96 hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives. The 96-hour LC50 for propargite for the most-sensitive freshwater species (Cyprinodon variegatus, Sheepshead minnow) is 60 ug/L. Therefore, the one-tenth LC50 value is 6 ug/L.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Samples were collected from Orestimba Creek at River Road.
Temporal Representation: Water samples were collected from Orestimba Creek at River Road between January 6, 2000 and September 7, 2005, as reported in the DPR Surface Water Database, at various intervals, including daily, twice weekly, weekly, twice monthly, monthly, every two months, and every 3 to 6 months.
Environmental Conditions:
QAPP Information: Data quality: Good. Minimum requirements for the Surface Water Database are:
Name of the sampling agency or organization
Date that each sample was collected
Date of each sample analysis
County where samples were taken
Detailed sampling location information (including latitude and longitude or township/range/section if available), detailed map or description of each sampling site (i.e., address, cross roads, etc.)
Name or description of water body sampled
Name of the active ingredient analyzed for; concentration detected (with unit of measurement), and limit of quantitation
Description of analytical QA/QC plan, or statement that no formal plan exists
Additional optional requirements are included on DPR¿s webpage at http://www.cdpr.ca.gov/docs/emon/surfwtr/caps/req.htm
QAPP Information Reference(s): Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
 
Line of Evidence (LOE) for Decision ID 75973, Propargite
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 26180
 
Pollutant: Propargite
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 32
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Thirty-six water samples (including 8 duplicate samples) were collected from Orestimba Creek, under the Pesticide TMDL program, between January and August 2003, representing 28 daily-averaged propargite concentrations. Zero of the 28 water samples contained propargite at a concentration that exceeds the Evaluation Guideline of 6 ug/L. Four water samples were collected from Orestimba Creek, under the Pesticide TMDL program, between January 14, 2006 and March 1, 2006.
Data Reference: Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Where valid testing has developed 96 hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives. The 96-hour LC50 for propargite for the most-sensitive freshwater species (Cyprinodon variegatus, Sheepshead minnow) is 60 ug/L. Therefore, the one-tenth LC50 value is 6 ug/L.
Guideline Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Spatial Representation: Water samples were collected from Orestimba Creek at River Road (2003) and at Kilburn Road (2006).
Temporal Representation: Water samples were collected from Orestimba Creek: on January 9, 2003; daily between February 13 and 17, 2003; on March 13, 2003; daily between March 15 and 18, 2003; weekly or every two weeks between March 27, 2003 and August 28, 2003; on January 14 and 15, 2006; on February 28, 2006; and on March 1, 2006.
Environmental Conditions:
QAPP Information: Data Quality: Good. All sampling, analysis and QA/QC protocols are described in a QAPP (Calanchini et al., 2006).
QAPP Information Reference(s): Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
 
 
DECISION ID
74829
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Salinity
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 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. Eleven of the samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Eleven of 133 samples exceeded the water quality objectives for electrical conductivity and total dissolved solids (collectively ¿salinity¿) and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 74829, Salinity
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22899
 
Pollutant: Salinity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 31
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Thirty-one samples were taken from Orestimba Creek between 2004 and 2006. None of the thirty-one samples exceed the California Secondary MCL for Municipal Water Quality Objectives for electrical conductivity in surface water.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The water quality objective used was the California Secondary MCL recommended level of 900 uS/cm. The Basin Plan includes chemical constituent water quality objectives that include (by reference) secondary maximum contaminant levels (MCL's) protective of MUN (CVRWQCB, 2007a).The secondary MCL's for electrical conductivity provide a range of values including a recommended level (900 uS/cm), upper level (1600 uS/cm) and a short-term level (2200 uS/cm). The 'recommended' concentration was used as it is intended to be protective of all drinking water uses. Though individual listing evaluations did not look at the water supply source serving the given geographic area, there are certain areas that receive supply waters (such as the Delta Mendota Canal) that at times may be elevated above the recommended level of the secondary MCL. Where future information is made available to document this to be the case, these water bodies may be re-evaluated in future listing cycles.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Orestimba Creek at Highway 33 in Stanislaus County.
Temporal Representation: Samples were collected between July 2004 and October 2006. Samples were collected at monthly intervals.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74829, Salinity
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22900
 
Pollutant: Salinity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 72
Number of Exceedances: 9
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Seventy-two samples were taken from Orestimba Creek between 2000 and 2006. Nine of the 72 samples exceed the California Secondary MCL for Municipal Water Quality Objectives for electrical conductivity in surface water.
Data Reference: Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The water quality objective used was the California Secondary MCL recommended level of 900 uS/cm. The Basin Plan includes chemical constituent water quality objectives that include (by reference) secondary maximum contaminant levels (MCL's) protective of MUN (CVRWQCB, 2007a).The secondary MCL's for electrical conductivity provide a range of values including a recommended level (900 uS/cm), upper level (1600 uS/cm) and a short-term level (2200 uS/cm). The 'recommended' concentration was used as it is intended to be protective of all drinking water uses. Though individual listing evaluations did not look at the water supply source serving the given geographic area, there are certain areas that receive supply waters (such as the Delta Mendota Canal) that at times may be elevated above the recommended level of the secondary MCL. Where future information is made available to document this to be the case, these water bodies may be re-evaluated in future listing cycles.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Orestimba Creek at Anderson, Bell Road, Highway 33, and Orestimba Road in Stanislaus County.
Temporal Representation: Samples were collected between November 2004 and November 2005. Samples were collected at bi-weekly intervals.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 74829, Salinity
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22901
 
Pollutant: Salinity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 30
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Thirty samples were taken from Orestimba Creek between 2004 and 2006. Two of the thirty samples exceed the California Secondary MCL for Municipal Water Quality Objectives for total dissolved solids in surface water.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The water quality objective used was the California Secondary MCL recommended level of 500 mg/L. The Basin Plan includes chemical constituent water quality objectives that include (by reference) secondary maximum contaminant levels (MCL's) protective of MUN (CVRWQCB, 2007a).The secondary MCL's for TDS provide a range of values including a recommended level (500 mg/L), upper level (1000 mg/L) and a short-term level (1500 mg/L). The 'recommended' concentration was used as it is intended to be protective of all drinking water uses. Though individual listing evaluations did not look at the water supply source serving the given geographic area, there are certain areas that receive supply waters (such as the Delta Mendota Canal) that at times may be elevated above the recommended level of the secondary MCL. Where future information is made available to document this to be the case, these water bodies may be re-evaluated in future listing cycles.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Orestimba Creek at Highway 33 in Stanislaus County.
Temporal Representation: Samples were collected between July 2004 and April 2006. Samples were collected at monthly intervals.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
 
DECISION ID
74523
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Selenium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of 26 samples exceed the 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 CWA 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. Zero of 26 samples exceed the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 74523, Selenium
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68469
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 26
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 26 samples exceed the criterion for Selenium.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for selenium is 0.05 mg/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/9/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74523, Selenium
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22931
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The Westside San Joaquin River Water Quality Coalition collected a total of 9 samples from 1 July 2004 to 31 October 2006. None of the samples collected exceeded the evaluation objective.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: CTR criterion of 5 ug/L, total recoverable Se, for the protection of freshwater aquatic life (4-day average concentration to protect from extended period of exposure).
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
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 at two locations: Orestimba Creek at Highway 33 and Orestimba Creek at Kilburn Road.
Temporal Representation: Monthly sampling occurred during the irrigation season(s).
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
 
DECISION ID
74322
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Simazine
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of 34 samples exceed the objective for MUN and 0 of 21 samples exceed the guideline for WARM.

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 CWA 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. Zero of 34 samples exceed the objective for MUN and 0 of 21 samples exceed the guideline for WARM and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 74322, Simazine
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22918
 
Pollutant: Simazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: 13 water samples were collected from Orestimba Creek from July 2004 through August 2006, representing 13 concentrations.0 of 13 concentrations exceeded the MCL (4 ug/L).
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: At a minimum, water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels (MCLs) specified in the following provisions of Title 22 of the California Code of Regulations, which are incorporated by reference into this plan: Tables 64431-A (Inorganic Chemicals) and 64431-B (Fluoride) of Section 64431, Table 64444-A (Organic Chemicals) of Section 64444, and Tables 64449-A (Secondary Maximum Contaminant Levels-Consumer Acceptance Limits) and 64449-B (Secondary Maximum Contaminant Levels-Ranges) of Section 64449.

The Maximum Contaminant Level (MCL) for simazine is 4 ug/L.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
Objective/Criterion Reference: California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring
 
Evaluation Guideline:
Guideline Reference: California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring
 
Spatial Representation: Samples were collected from Orestimba Creek at Highway 33.
Temporal Representation: Samples were collected biweekly or monthly from July 2004 through September 2006.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74322, Simazine
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68480
 
Pollutant: Simazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Simazine.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Simazine, 90 ug/L, is the EC50 for Navicula pelliculosa (freshwater diatom). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74322, Simazine
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68481
 
Pollutant: Simazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Simazine.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California primary maximum contaminant level for Simazine is 4 ug/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92587
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Thiobencarb/Bolero
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the eight samples exceed the MUN water Criteria/Objective, zero of the eight samples exceed the WARM water evaluation guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of eight samples exceed the MUN water Criteria/Objective, zero of eight samples exceed the WARM water evaluation guideline, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92587, Thiobencarb/Bolero
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68482
 
Pollutant: Thiobencarb/Bolero
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Thiobencarb.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Thiobencarb, 1.4 ug/L, is a maximum acceptable toxicicant concentration (MATC) calculated for Daphnia magna (Water flea). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 92587, Thiobencarb/Bolero
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68483
 
Pollutant: Thiobencarb/Bolero
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Thiobencarb.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of Thiobencarb in excess of 1.0 µg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-1/5/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92642
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Toxaphene
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the zero samples exceed each of the MUN and WARM water Criteria/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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of zero samples exceed each of the MUN and WARM water Criteria/Objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92642, Toxaphene
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68484
 
Pollutant: Toxaphene
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Toxaphene criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0002 ug/L. (California Toxics Rule, 2000)
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 92642, Toxaphene
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68497
 
Pollutant: Toxaphene
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Toxaphene criterion for the protection of human health from the consumption of water and organisms is 0.00073 ug/L. (California Toxics Rule, 2000)
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
77752
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Trifluralin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 13 samples exceed the guideline.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 13 samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 77752, Trifluralin
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68498
 
Pollutant: Trifluralin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for Trifluralin.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Trifluralin, 1.58 ug/L, is a maximum acceptable toxicicant concentration (MATC) calculated for Oncorhyncus mykiss (Rainbow trout). USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/11/2008-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
77753
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Zinc
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of 25 samples exceed the 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 CWA 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. Zero of 25 samples exceed the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 77753, Zinc
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68499
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 26
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 26 samples exceed the criterion for Zinc.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California secondary maximum contaminant level for zinc is 5.0 mg/L.
Objective/Criterion Reference: Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 1/9/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 77753, Zinc
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68500
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed AgWaiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 5 samples exceed the criterion for Zinc.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The chromium criterion in freshwater is hardness-dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness-dependent formula for metals criteria.
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/10/2009-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91822
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: alpha-Endosulfan (Endosulfan 1)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed the Criteria/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 CWA 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. Zero of 21 samples exceeded the Criteria/Objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

`
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation: `
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91822, alpha-Endosulfan (Endosulfan 1)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78685
 
Pollutant: alpha-Endosulfan (Endosulfan 1)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Endosulfan I.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule criteria for Eendosulfan I to protect human health for waters that include the designated use of MUN is 110 ug/L.
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: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91766
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: alpha.-BHC (Benzenehexachloride or alpha-HCH)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed each of the MUN 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 CWA 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. Zero of 21 samples exceeded each of the MUN water quality objectives and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91766, alpha.-BHC (Benzenehexachloride or alpha-HCH)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68538
 
Pollutant: alpha.-BHC (Benzenehexachloride or alpha-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for HCH, alpha.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The HCH, alpha criterion, 0.0039 ug/L, is for the protection of human health from the consumption of water and organisms. (California Toxics Rule, 2002)
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 91766, alpha.-BHC (Benzenehexachloride or alpha-HCH)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78689
 
Pollutant: alpha.-BHC (Benzenehexachloride or alpha-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for HCH, alpha.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The BHC, alpha criteria for the protection of human health from the consumption of water and organisms is 0.0039 ug/L (California Toxics Rule, 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: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91823
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: beta-BHC (Benzenehexachloride or beta-HCH)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 42 samples exceed the Criteria/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 CWA 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. Zero of 42 samples exceeded the Criteria/Objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91823, beta-BHC (Benzenehexachloride or beta-HCH)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68549
 
Pollutant: beta-BHC (Benzenehexachloride or beta-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for HCH, beta.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The HCH, beta criterion for the protection of human health from the consumption of water and organisms is 0.014 ug/L (California Toxics Rule, 2002).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 91823, beta-BHC (Benzenehexachloride or beta-HCH)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78690
 
Pollutant: beta-BHC (Benzenehexachloride or beta-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for HCH, beta.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The BHC, beta criteria for the protection of human health from the consumption of water and organisms is 0.014 ug/L (California Toxics Rule, 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: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
91875
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: beta-Endosulfan (Endosulfan 2)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. Zero of the 21 samples exceed the Criteria/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 CWA 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. Zero of 21 samples exceeded the Criteria/Objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91875, beta-Endosulfan (Endosulfan 2)
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78686
 
Pollutant: beta-Endosulfan (Endosulfan 2)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Endosulfan II.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule criteria for Endosulfan II to protect human health for waters that include the designated use of MUN is 110 ug/L.
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: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 2/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
74995
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: pH
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 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. 10 of 181 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. 10 of 181 samples exceeded the Evaluation Guideline and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 74995, pH
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78696
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 71
Number of Exceedances: 7
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 7 of 71 samples exceed the criterion for pH.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 7/6/2004-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74995, pH
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22906
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 38
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The Westside San Joaquin Water Quality Coalition collected 38 samples from July 2004 to October 2006. Two out of 38 samples were outside the acceptable range; one sample was higher than the acceptable range and one sample was lower than the acceptable range.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH of water shall not be depressed below 6.5,raised above 8.5, or changed at any time more than 0.5 units from normal ambient pH.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Orestimba Creek at Highway 33.
Temporal Representation: Sampling occurred from July 2004 to October 2006.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 74995, pH
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 22907
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 72
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The Central Valley Regional Water Quality Control Board Surface Water Ambient Monitoring Program collected 72 samples from November 2004 to November 2005. One out of 72 samples was outside the acceptable range; the sample was higher than the acceptable range.
Data Reference: Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The pH of water shall not be depressed below 6.5,raised above 8.5, or changed at any time more than 0.5 units from normal ambient pH.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from four locations: Orestimba Creek at Anderson, Orestimba Creek at Bell road, Orestimba Creek at Highway 33, and Orestimba Creek at Orestimba Road.
Temporal Representation: Sampling occurred from November 2004 to November 2005.
Environmental Conditions:
QAPP Information: Data quality: Good. Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s): Quality Assurance Management 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
92471
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Oxygen, Dissolved
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. 26 of the 29 samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. 26 of 29 samples exceed the water quality objectives and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92471, Oxygen, Dissolved
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68453
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 29
Number of Exceedances: 26
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data to determine beneficial use support: 26 of 29 sample results exceed the criterion for Oxygen, Dissolved.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence was collected at one monitoring site [Orestimba Creek @ Hwy 33-541STC519].
Temporal Representation: Data was collected monthly between 3/12/2007 and 8/11/2009. Six pairs of sample results were collected within 7-day periods; the sample results were averaged for each 7-day period.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92530
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Specific Conductivity
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. 10 of the 34 samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. 10 of 34 samples exceed the water quality objectives and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92530, Specific Conductivity
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 68591
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 34
Number of Exceedances: 10
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Ag Waiver data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 10 of 34 samples exceed the criterion for Conductivity(Us).
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California secondary maximum contaminant levels for electrical conductivity provide a range of values including a recommended level (900 uS/cm), an upper level (1,600 uS/cm) and a short-term level (2,200 uS/cm). The recommended level of 900 uS/cm was used as it is protective of all drinking water uses.
Objective/Criterion Reference: Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 3/12/2007-8/11/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):
 
 
DECISION ID
92641
Region 5     
Orestimba Creek (above Kilburn Road)
 
Pollutant: Total Dissolved Solids
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA 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. 14 of the 56 samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. 14 of 56 samples exceed the water quality objectives and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 92641, Total Dissolved Solids
Region 5     
Orestimba Creek (above Kilburn Road)
 
LOE ID: 78681
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 56
Number of Exceedances: 14
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed ILRP data for Orestimba Creek (above Kilburn Road) to determine beneficial use support and results are as follows: 14 of 56 samples exceed the criterion for Dissolved Solids.
Data Reference: Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.
 
SWAMP Data:
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: At a minimum, water designated for MUN shall not contain concentrations of chemical constituents in excess of the MCL specified in Title 22 of the California Code of Regulations. The secondary MCL for Total Dissolved Solids is 500 mg/L.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Orestimba Creek (above Kilburn Road) was collected at 1 monitoring site [ Orestimba Creek @ Hwy 33 - 541STC519]
Temporal Representation: Data was collected over the time period 7/6/2004-2/18/2009. The results for samples collected on the same date were averaged before they were assessed.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.
QAPP Information Reference(s):