Draft California 2014 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Tapo Canyon
Water Body ID: CAR4034100020110722112902
Water Body Type: River & Stream
 
DECISION ID
64346
Region 4     
Tapo Canyon
 
Pollutant: Aldrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64346, Aldrin
Region 4     
Tapo Canyon
 
LOE ID: 89377
 
Pollutant: Aldrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Aldrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Aldrin criteria for the protection of saltwater aquatic life is 1.3 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64346, Aldrin
Region 4     
Tapo Canyon
 
LOE ID: 89376
 
Pollutant: Aldrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Aldrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The aldrin criterion maximum concentration to protect aquatic life in freshwater is 3 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
67272
Region 4     
Tapo Canyon
 
Pollutant: Ammonia
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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.

1 line of evidence is available in the administrative record to assess this pollutant.
1 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 1 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 67272, Ammonia
Region 4     
Tapo Canyon
 
LOE ID: 89389
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for Ammonia as N, Total.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface water shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: Aquatic Life Ambient Water Quality Criteria for Ammonia Freshwater (USEPA 2013): the 30-day rolling average concentration (criterion continuous concentration or CCC) of total ammonia nitrogen(in mg TAN/L) in freshwater are not to be exceeded more than once every three years on average. The CCC values are based on pH and temperature. The CCC formula is found on page 46 and the table of CCC values is on page 49.
Guideline Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64347
Region 4     
Tapo Canyon
 
Pollutant: Azinphos-methyl (Guthion)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 3 samples exceeded the CRITERIA.
0 of 3 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 3 and 0 of 3 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64347, Azinphos-methyl (Guthion)
Region 4     
Tapo Canyon
 
LOE ID: 89391
 
Pollutant: Azinphos-methyl (Guthion)
LOE Subgroup: Pollutant-Water
Matrix: Water
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Azinphos Methyl.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The Azinphos methyl (Guthion) criteria for the protection of freshwater aquatic life is 0.01 ug/L (National Recommended Water Quality Criteria, 2009).
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 Tapo Canyon was collected at 1 monitoring site [ Tapo Canyon Creek - S04T_TAPO]
Temporal Representation: Data was collected over the time period 9/16/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64347, Azinphos-methyl (Guthion)
Region 4     
Tapo Canyon
 
LOE ID: 89406
 
Pollutant: Azinphos-methyl (Guthion)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Azinphos Methyl.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The Azinphos methyl (Guthion) criteria for the protection of saltwater aquatic life is 0.01 ug/L (National Recommended Water Quality Criteria, 2009).
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 Tapo Canyon was collected at 1 monitoring site [ Tapo Canyon Creek - S04T_TAPO]
Temporal Representation: Data was collected over the time period 9/16/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64349
Region 4     
Tapo Canyon
 
Pollutant: Bifenthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64349, Bifenthrin
Region 4     
Tapo Canyon
 
LOE ID: 89408
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Bifenthrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The genus mean acute value for a mysid (Mysidopsis bahia) of 0.00397 ug/L (DFG 00-6, 2000).
Guideline Reference: Hazard Assessment of the Synthetic Pyrethroid Insecticides Bifenthrin, Cypermethrin, Esfenvalerate, and Permethrin to Aquatic Organisms in the Sacramento-San Joaquin River System. California Department of Fish and Game. Office of Spill Prevention and Response, Administrative Report 00-6
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64349, Bifenthrin
Region 4     
Tapo Canyon
 
LOE ID: 89417
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Bifenthrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Bifenthrin does not exceed 0.0006 ug/L.
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64352
Region 4     
Tapo Canyon
 
Pollutant: Chlorpyrifos
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64352, Chlorpyrifos
Region 4     
Tapo Canyon
 
LOE ID: 89207
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Chlorpyrifos.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 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
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64352, Chlorpyrifos
Region 4     
Tapo Canyon
 
LOE ID: 89208
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Chlorpyrifos.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The saltwater criterion continuous concentration to protect aquatic organisms is 0.009 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
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64353
Region 4     
Tapo Canyon
 
Pollutant: Cyfluthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
1 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 1 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64353, Cyfluthrin
Region 4     
Tapo Canyon
 
LOE ID: 89217
 
Pollutant: Cyfluthrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Cyfluthrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of cyfluthrin does not exceed 0.00005 ug/L and if the 1-h average concentration does not exceed 0.0003 ug/L. For this assessment, the 4-day average concentration was used. Mixtures of cyfluthrin and other pyrethroids should be considered in an additive manner. (Fojut et al. 2012)
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 6/4/2007-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64354
Region 4     
Tapo Canyon
 
Pollutant: Cyhalothrin, Lambda
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64354, Cyhalothrin, Lambda
Region 4     
Tapo Canyon
 
LOE ID: 89218
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Cyhalothrin, lambda, total.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Cyhalothrin, lambda, total does not exceed 0.0005 ug/L.
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64355
Region 4     
Tapo Canyon
 
Pollutant: Cypermethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64355, Cypermethrin
Region 4     
Tapo Canyon
 
LOE ID: 89219
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Cypermethrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Marine communities, including vertebrate, invertebrate, and plant species, shall not be degraded (Ocean Plan).
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The genus mean acute value for a grass shrimp (Palaemonetes pugio) of 0.016 ug/L (DFG 00-6, 2000).
Guideline Reference: Hazard Assessment of the Synthetic Pyrethroid Insecticides Bifenthrin, Cypermethrin, Esfenvalerate, and Permethrin to Aquatic Organisms in the Sacramento-San Joaquin River System. California Department of Fish and Game. Office of Spill Prevention and Response, Administrative Report 00-6
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64355, Cypermethrin
Region 4     
Tapo Canyon
 
LOE ID: 89230
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Cypermethrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The interim freshwater criterion maximum concentration is 0.002 ug/L (DFG 00-6, 2000).
Guideline Reference: Hazard Assessment of the Synthetic Pyrethroid Insecticides Bifenthrin, Cypermethrin, Esfenvalerate, and Permethrin to Aquatic Organisms in the Sacramento-San Joaquin River System. California Department of Fish and Game. Office of Spill Prevention and Response, Administrative Report 00-6
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64447
Region 4     
Tapo Canyon
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
1 of 7 samples exceeded the CRITERION.
1 of 7 samples exceeded the CRITERION.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 1 of 7 and 1 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64447, DDT (Dichlorodiphenyltrichloroethane)
Region 4     
Tapo Canyon
 
LOE ID: 89260
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for DDT(p,p).
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saline water is 0.001 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64447, DDT (Dichlorodiphenyltrichloroethane)
Region 4     
Tapo Canyon
 
LOE ID: 89248
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for DDT(p,p).
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64448
Region 4     
Tapo Canyon
 
Pollutant: Dacthal
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64448, Dacthal
Region 4     
Tapo Canyon
 
LOE ID: 89231
 
Pollutant: Dacthal
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Dacthal.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: According to the USEPA Office of Pesticide Programs Ecotoxicity database, the aquatic life LC50 for Dacthal is 6600 ug/L.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64475
Region 4     
Tapo Canyon
 
Pollutant: Deltamethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64475, Deltamethrin
Region 4     
Tapo Canyon
 
LOE ID: 89261
 
Pollutant: Deltamethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Deltamethrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The evaluation guideline for Deltamethrin is the maximum acceptable toxicant concentration (MATC) of 0.02 ug/L.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64449
Region 4     
Tapo Canyon
 
Pollutant: Demeton
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64449, Demeton
Region 4     
Tapo Canyon
 
LOE ID: 89274
 
Pollutant: Demeton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Demeton.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: USEPA National Recommended Water Quality Criteria lists criterion continuous concentrations for Demeton to protect aquatic life in freshwater and saltwater is 0.1 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64449, Demeton
Region 4     
Tapo Canyon
 
LOE ID: 89273
 
Pollutant: Demeton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Demeton.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: USEPA National Recommended Water Quality Criteria lists criterion continuous concentrations for Demeton to protect aquatic life in freshwater and saltwater is 0.1 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64492
Region 4     
Tapo Canyon
 
Pollutant: Diazinon
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64492, Diazinon
Region 4     
Tapo Canyon
 
LOE ID: 89275
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Diazinon.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The chronic criterion for diazinon to protect saltwater aquatic organisms is 0.82 ug/L (EPA-822-R-05-006).
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64492, Diazinon
Region 4     
Tapo Canyon
 
LOE ID: 89293
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Diazinon.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
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: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64502
Region 4     
Tapo Canyon
 
Pollutant: Dichlorvos
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64502, Dichlorvos
Region 4     
Tapo Canyon
 
LOE ID: 89295
 
Pollutant: Dichlorvos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Dichlorvos.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: According to the USEPA Office of Pesticide Programs Ecotoxicity database, the aquatic life MATC for Dichlorvos is 7.2 ug/L.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64504
Region 4     
Tapo Canyon
 
Pollutant: Dicofol
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64504, Dicofol
Region 4     
Tapo Canyon
 
LOE ID: 89311
 
Pollutant: Dicofol
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Dicofol.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The evaluation guideline for Dicofol is the maximum acceptable toxicant concentration (MATC) of 5.9 ug/L.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64507
Region 4     
Tapo Canyon
 
Pollutant: Dieldrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64507, Dieldrin
Region 4     
Tapo Canyon
 
LOE ID: 89314
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Dieldrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saltwater is 0.0019 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64507, Dieldrin
Region 4     
Tapo Canyon
 
LOE ID: 89312
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Dieldrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64450
Region 4     
Tapo Canyon
 
Pollutant: Dimethoate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64450, Dimethoate
Region 4     
Tapo Canyon
 
LOE ID: 89330
 
Pollutant: Dimethoate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Dimethoate.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The evaluation guideline for Dimethoate is the median lethal concentration (LC50; 43 ug/L).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64451
Region 4     
Tapo Canyon
 
Pollutant: Disulfoton
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64451, Disulfoton
Region 4     
Tapo Canyon
 
LOE ID: 89341
 
Pollutant: Disulfoton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Disulfoton.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The USEPA national ambient water quality criteria for freshwater aquatic life instantaneous maximum for disulfoton is 0.05 g/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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64452
Region 4     
Tapo Canyon
 
Pollutant: Endosulfan
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64452, Endosulfan
Region 4     
Tapo Canyon
 
LOE ID: 89342
 
Pollutant: Endosulfan
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Endosulfan, Total.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The endosulfan criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L. This value corresponds to the sum of alpha-endosulfan and beta-endosulfan (USEPA National Recommended Water Quality Criteria, 2006).
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64453
Region 4     
Tapo Canyon
 
Pollutant: Endosulfan sulfate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64453, Endosulfan sulfate
Region 4     
Tapo Canyon
 
LOE ID: 89360
 
Pollutant: Endosulfan sulfate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Endosulfan Sulfate.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The USEPA national ambient water quality criteria for freshwater aquatic life 24 hour average maximum for endosulfan sulfate is 0.056 g/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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64510
Region 4     
Tapo Canyon
 
Pollutant: Endrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64510, Endrin
Region 4     
Tapo Canyon
 
LOE ID: 89380
 
Pollutant: Endrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Endrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saltwater is 0.0023 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64510, Endrin
Region 4     
Tapo Canyon
 
LOE ID: 89362
 
Pollutant: Endrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Endrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64512
Region 4     
Tapo Canyon
 
Pollutant: Endrin aldehyde
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64512, Endrin aldehyde
Region 4     
Tapo Canyon
 
LOE ID: 89392
 
Pollutant: Endrin aldehyde
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Endrin Aldehyde.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The Endrin Aldehyde criteria for the protection of human health from the fish consumption component of water contact recreation (REC-1) use is 0.81 ug/L (California Toxics Rule, 2000).
Guideline 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
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64454
Region 4     
Tapo Canyon
 
Pollutant: Esfenvalerate/Fenvalerate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 14 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 14 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64454, Esfenvalerate/Fenvalerate
Region 4     
Tapo Canyon
 
LOE ID: 89394
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Fenvalerate.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The evaluation guideline for Fenvalerate is the median lethal concentration (LC50; 1.13 ug/L).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64454, Esfenvalerate/Fenvalerate
Region 4     
Tapo Canyon
 
LOE ID: 89393
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Esfenvalerate.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: According to the USEPA Office of Pesticide Programs Ecotoxicity database, the aquatic life EC50 for Esfenvalerate is 0.9 ug/L.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64515
Region 4     
Tapo Canyon
 
Pollutant: Ethoprop
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64515, Ethoprop
Region 4     
Tapo Canyon
 
LOE ID: 89395
 
Pollutant: Ethoprop
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Ethoprop.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The evaluation guideline for Ethoprop is the maximum acceptable toxicant concentration (MATC) of 1.4 ug/L.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64517
Region 4     
Tapo Canyon
 
Pollutant: Fenpropathrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64517, Fenpropathrin
Region 4     
Tapo Canyon
 
LOE ID: 89409
 
Pollutant: Fenpropathrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Fenpropathrin.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The evaluation guideline for Fenpropathrin is the median lethal concentration (LC50; 2.2 ug/L).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64518
Region 4     
Tapo Canyon
 
Pollutant: Heptachlor
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64518, Heptachlor
Region 4     
Tapo Canyon
 
LOE ID: 89410
 
Pollutant: Heptachlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Heptachlor.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64518, Heptachlor
Region 4     
Tapo Canyon
 
LOE ID: 89421
 
Pollutant: Heptachlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Heptachlor.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saline water is 0.0036 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64522
Region 4     
Tapo Canyon
 
Pollutant: Heptachlor epoxide
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64522, Heptachlor epoxide
Region 4     
Tapo Canyon
 
LOE ID: 89422
 
Pollutant: Heptachlor epoxide
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Heptachlor Epoxide.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64522, Heptachlor epoxide
Region 4     
Tapo Canyon
 
LOE ID: 89424
 
Pollutant: Heptachlor epoxide
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Heptachlor Epoxide.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Heptachlor epoxide criteria for the protection of saltwater aquatic life is 0.0036 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64523
Region 4     
Tapo Canyon
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64523, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 4     
Tapo Canyon
 
LOE ID: 89433
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for BHC, gamma(Lindane).
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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: 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64523, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 4     
Tapo Canyon
 
LOE ID: 89435
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for BHC, gamma(Lindane).
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The gamma-BHC (Lindane) criterion maximum concentration to protect aquatic life in saline water is 0.16 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64527
Region 4     
Tapo Canyon
 
Pollutant: Methidathion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 3 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 3 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64527, Methidathion
Region 4     
Tapo Canyon
 
LOE ID: 89212
 
Pollutant: Methidathion
LOE Subgroup: Pollutant-Water
Matrix: Water
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Methidathion.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The evaluation guideline for Methidathion is the maximum acceptable toxicant concentration (MATC) of 0.86 ug/L.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ Tapo Canyon Creek - S04T_TAPO]
Temporal Representation: Data was collected over the time period 9/16/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64455
Region 4     
Tapo Canyon
 
Pollutant: Methoxychlor
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64455, Methoxychlor
Region 4     
Tapo Canyon
 
LOE ID: 89220
 
Pollutant: Methoxychlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Methoxychlor.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The USEPA national ambient water quality criteria for freshwater aquatic life instantaneous maximum for methoxychlor is 0.03 g/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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64528
Region 4     
Tapo Canyon
 
Pollutant: Methyl Parathion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64528, Methyl Parathion
Region 4     
Tapo Canyon
 
LOE ID: 89222
 
Pollutant: Methyl Parathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Parathion, methyl.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The Dept. of Fish and Game instantaneous criteria for methyl parathion is 0.08 ug/L.
Guideline Reference: Hazard Assessment of the Synthetic Pyrethroid Insecticides Bifenthrin, Cypermethrin, Esfenvalerate, and Permethrin to Aquatic Organisms in the Sacramento-San Joaquin River System. California Department of Fish and Game. Office of Spill Prevention and Response, Administrative Report 00-6
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64529
Region 4     
Tapo Canyon
 
Pollutant: Mirex
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64529, Mirex
Region 4     
Tapo Canyon
 
LOE ID: 89234
 
Pollutant: Mirex
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Mirex.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No indvidual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneifical uses.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The criterion continuous concentraion for Mirex is 0.001 ug/l from the National Recommended Water Quality Criteria.
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64532
Region 4     
Tapo Canyon
 
Pollutant: Oxygen, Dissolved
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 11 samples exceeded the OBJECTIVE.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 11 samples exceeded 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 26 samples is needed to determine if a beneficial use is fully supported using table 3.2.
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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64532, Oxygen, Dissolved
Region 4     
Tapo Canyon
 
LOE ID: 89236
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 11
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 11 samples exceed the criterion for Oxygen, dissolved.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region (page 3-11) states that: "The dissolved oxygen content of all surface waters designated as WARM shall not be depressed below 5 mg/L as a result of waste discharges."
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 6/4/2007-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64533
Region 4     
Tapo Canyon
 
Pollutant: Parathion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 3 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 3 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64533, Parathion
Region 4     
Tapo Canyon
 
LOE ID: 89250
 
Pollutant: Parathion
LOE Subgroup: Pollutant-Water
Matrix: Water
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Parathion, Ethyl.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The criterion continuous concentraion for Parathion, Ethyl is 0.013 ug/l from the National Recommended Water Quality Criteria.
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 Tapo Canyon was collected at 1 monitoring site [ Tapo Canyon Creek - S04T_TAPO]
Temporal Representation: Data was collected over the time period 9/16/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64534
Region 4     
Tapo Canyon
 
Pollutant: Permethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.
0 of 0 sample exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 and 0 of 0 sample exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64534, Permethrin
Region 4     
Tapo Canyon
 
LOE ID: 89252
 
Pollutant: Permethrin, total
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Permethrin, Total. Seven sample result(s) 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 from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Permethrin; Permethrin, total does not exceed 0.0002 ug/L.
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64534, Permethrin
Region 4     
Tapo Canyon
 
LOE ID: 89251
 
Pollutant: Permethrin, total
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Permethrin, Total.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The interim criteria maximum concentration to protect aquatic life in saline water is 0.001 ug/L (DFG 00-6, 2000).
Guideline Reference: Hazard Assessment of the Synthetic Pyrethroid Insecticides Bifenthrin, Cypermethrin, Esfenvalerate, and Permethrin to Aquatic Organisms in the Sacramento-San Joaquin River System. California Department of Fish and Game. Office of Spill Prevention and Response, Administrative Report 00-6
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64535
Region 4     
Tapo Canyon
 
Pollutant: Phorate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant.
0 of 7 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 7 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64535, Phorate
Region 4     
Tapo Canyon
 
LOE ID: 89276
 
Pollutant: Phorate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Phorate.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The evaluation guideline for Phorate is the median lethal concentration (LC50; 2 ug/L).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64537
Region 4     
Tapo Canyon
 
Pollutant: Phosmet
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant.
0 of 3 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 3 samples exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64537, Phosmet
Region 4     
Tapo Canyon
 
LOE ID: 89279
 
Pollutant: Phosmet
LOE Subgroup: Pollutant-Water
Matrix: Water
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Phosmet.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: According to the USEPA Office of Pesticide Programs Ecotoxicity database, the aquatic life EC50 for Phosmet is 5.6 ug/L.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ Tapo Canyon Creek - S04T_TAPO]
Temporal Representation: Data was collected over the time period 9/16/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64541
Region 4     
Tapo Canyon
 
Pollutant: Temperature, water
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 11 samples exceeded the OBJECTIVE.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 11 samples exceeded 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 26 samples is needed to determine if a beneficial use is fully supported using table 3.2.
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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64541, Temperature, water
Region 4     
Tapo Canyon
 
LOE ID: 89315
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 11
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 11 samples exceed the criterion for Water Temperature.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: For waters designated WARM, water temperature shall not be altered by more than 5 deg. F above the natural temperature. At no time shall these WARM-designated waters be raised above 80 deg. F as a result of waste discharges.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 6/4/2007-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64543
Region 4     
Tapo Canyon
 
Pollutant: Toxaphene
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 0 sample exceeded the CRITERIA.
0 of 0 sample exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 0 and 0 of 0 sample exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64543, Toxaphene
Region 4     
Tapo Canyon
 
LOE ID: 89318
 
Pollutant: Toxaphene
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene. Seven sample result(s) 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 from the Ag Waiver Program, 2007-2009.
 
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64543, Toxaphene
Region 4     
Tapo Canyon
 
LOE ID: 89333
 
Pollutant: Toxaphene
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene. Seven sample result(s) 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 from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Toxaphene criteria for the protection of saltwater aquatic life 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64547
Region 4     
Tapo Canyon
 
Pollutant: pH
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 are necessary to assess listing status.

4 lines of evidence are available in the administrative record to assess this pollutant.
0 of 11 samples exceeded the OBJECTIVE.
0 of 11 samples exceeded the OBJECTIVE.
0 of 11 samples exceeded the OBJECTIVE.
0 of 11 samples exceeded the OBJECTIVE.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 11, 0 of 11, 0 of 11, and 0 of 11 samples exceeded 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 26 samples is needed to determine if a beneficial use is fully supported using table 3.2.
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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64547, pH
Region 4     
Tapo Canyon
 
LOE ID: 89264
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 11
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 11 samples exceed the criterion for pH.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Los Angeles Basin: the pH for insland surface waters, bays, or estuaries shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 6/4/2007-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64547, pH
Region 4     
Tapo Canyon
 
LOE ID: 89262
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 11
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 11 samples exceed the criterion for pH.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Los Angeles Basin: the pH for insland surface waters, bays, or estuaries shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 6/4/2007-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64547, pH
Region 4     
Tapo Canyon
 
LOE ID: 89266
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Marine Habitat
 
Number of Samples: 11
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 11 samples exceed the criterion for pH.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Los Angeles Basin: the pH for insland surface waters, bays, or estuaries shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 6/4/2007-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64547, pH
Region 4     
Tapo Canyon
 
LOE ID: 89263
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 11
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 0 of 11 samples exceed the criterion for pH.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Los Angeles Basin: the pH for insland surface waters, bays, or estuaries shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 6/4/2007-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64350
Region 4     
Tapo Canyon
 
Pollutant: Chlordane
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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.

3 lines of evidence are available in the administrative record to assess this pollutant.
2 of 7 samples exceeded the CRITERIA.
2 of 7 samples exceeded the CRITERIA.
2 of 5 samples exceeded the WATER TOXICITY GUIDELINE.

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. 2 of 7 and 2 of 7 samples exceeded the CRITERIA, and 2 of 5 samples exceeded the WATER TOXICITY GUIDELINE. These exceeded 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64350, Chlordane
Region 4     
Tapo Canyon
 
LOE ID: 89418
 
Pollutant: Chlordane
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 2 of 7 samples exceed the criterion for Chlordane, Total.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0043 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
Line of Evidence (LOE) for Decision ID 64350, Chlordane
Region 4     
Tapo Canyon
 
LOE ID: 89420
 
Pollutant: Chlordane
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Marine Habitat
 
Number of Samples: 7
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 2 of 7 samples exceed the criterion for Chlordane, Total.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saltwater is 0.004 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64351
Region 4     
Tapo Canyon
 
Pollutant: Chloride
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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.
5 of 8 samples exceeded the 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. 5 of 8 samples exceeded the OBJECTIVE 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64351, Chloride
Region 4     
Tapo Canyon
 
LOE ID: 89431
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 5
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 5 of 8 samples exceed the criterion for Chloride.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Table 3-8 of The Water Quality Control Plan for the Los Angeles Region specifies the Chloride objective for Tapo Canyon within the Santa Clara River's Between Blue Cut gaging station (approx. 1 mile west of LA/Ventura county line) and A Street, Fillmore reach boundary as 100 mg/L.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64445
Region 4     
Tapo Canyon
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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.

2 line of evidence is available in the administrative record to assess this pollutant.
3 of 3 samples exceeded the CRITERIA.
2 of 5 samples exceeded the WATER TOXICITY GUIDELINE.

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. 3 of 3 samples exceeded the CRITERIA and 2 of 5 samples exceeded the WATER TOXICITY GUIDELINE. These 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64445, DDD (Dichlorodiphenyldichloroethane)
Region 4     
Tapo Canyon
 
LOE ID: 89233
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 3 of 3 samples exceed the criterion for DDD(p,p). Four sample result(s) 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 from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The DDD(p,p) criterion for the protection of human health from the fish consumption component of water contact recreation (REC-1) use is 0.00084 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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64525
Region 4     
Tapo Canyon
 
Pollutant: Malathion
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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.
2 of 7 samples exceeded the CRITERIA.

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. 2 of 7 samples exceeded the CRITERIA and this exceeds 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64525, Malathion
Region 4     
Tapo Canyon
 
LOE ID: 89211
 
Pollutant: Malathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 2 of 7 samples exceed the criterion for Malathion.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Malathion does not exceed 0.028 ug/L.
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 Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64540
Region 4     
Tapo Canyon
 
Pollutant: Sulfates
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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.
6 of 8 samples exceeded the 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. 6 of 8 samples exceeded the OBJECTIVE 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64540, Sulfates
Region 4     
Tapo Canyon
 
LOE ID: 89297
 
Pollutant: Sulfates
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 6
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 6 of 8 samples exceed the criterion for Sulfate.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Table 3-8 of The Water Quality Control Plan for the Los Angeles Region specifies the Sulfate objective for Tapo Canyon within the Santa Clara River's Between Blue Cut gaging station (approx. 1 mile west of LA/Ventura county line) and A Street, Fillmore reach boundary as 600 mg/L.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64542
Region 4     
Tapo Canyon
 
Pollutant: Total Dissolved Solids
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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.
7 of 8 samples exceeded the 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. 7 of 8 samples exceeded the OBJECTIVE 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64542, Total Dissolved Solids
Region 4     
Tapo Canyon
 
LOE ID: 89316
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 7
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed Agwaiver data for Tapo Canyon to determine beneficial use support and results are as follows: 7 of 8 samples exceed the criterion for Dissolved Solids.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Table 3-8 of The Water Quality Control Plan for the Los Angeles Region specifies the Dissolved Solids objective for Tapo Canyon within the Santa Clara River's Between Blue Cut gaging station (approx. 1 mile west of LA/Ventura county line) and A Street, Fillmore reach boundary as 1300 mg/L.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Tapo Canyon was collected at 1 monitoring site [ S04T_TAPO background site upstream of agricultural operations - S04T_TAPO_BKGD]
Temporal Representation: Data was collected over the time period 1/5/2008-8/4/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s): Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.
 
 
DECISION ID
64544
Region 4     
Tapo Canyon
 
Pollutant: Toxicity
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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.

1 line of evidence is available in the administrative record to assess this pollutant.
2 of 5 samples exceeded the CRITERIA.

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. 2 of 5 samples exceeded the CRITERIA and this exceeds 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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 64544, Toxicity
Region 4     
Tapo Canyon
 
LOE ID: 89343
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Fivesamples were collected to evaluate water toxicity. Two of the five samples exhibited significant toxicity. The toxicity tests included survival of Hyalella azteca, cell density for Thalassiosira pseudonana, survival and growth of Americamysis bahia, and total cell count for Selenastrum capricornutum. Statistically significant toxicity to Thalassiosira pseudonana was observed on (6/4/2007) and Selenastrum capricornutum on 8/4/2009.
Data Reference: Data for various Pollutants from the Ag Waiver Program, 2007-2009.
 
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 4 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. The t-test is used to determine if there is a statistically significant decrease in organism response in the sample as compared to the control.
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 sample was collected at Tapo Canyon Creek.
Temporal Representation: The sample was collected in June and September 2007, January and September 2008 and August 2009.
Environmental Conditions:
QAPP Information: Data quality is good. A QAPP and monitoring plan was submitted. Data was collected by the Ventura County Agricultural Irrigated Lands Group for Order No. R4- 2005-0080.)
QAPP Information Reference(s):