Final California 2024 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Hopper Creek
Water Body ID:	CAR4034100020020131112807
Water Body Type:	River & Stream


DECISION ID	151084	Region 4
Hopper Creek

Pollutant:	Benthic Community Effects
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects. One line of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. One of one benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. However, a minimum of two benthic-macroinvertebrate samples are needed to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of one benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. The available information is insufficient to determine whether the waterbody/pollutant combination should be placed on the 303(d) List of impaired waters at this time. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 151084, Benthic Community Effects	Region 4
Hopper Creek

LOE ID:

305290

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 403S00831 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.510583487 to 0.510583487.

Data Reference:

California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 4.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

Samples were collected from station 403S00831.

Temporal Representation:

Samples were collected from 6/10/2010 to 6/10/2010.

Environmental Conditions:

QAPP Information:

Data were collected using Surface Water Ambient Monitoring Program protocols

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.


DECISION ID	152570	Region 4
Hopper Creek

Pollutant:	Bifenthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84818 has been replaced by LOE 310131 due to a reassessment of data using updated UCD Criterion.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152570, Bifenthrin	Region 4
Hopper Creek

LOE ID:

310131

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Bifenthrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152570, Bifenthrin	Region 4
Hopper Creek

LOE ID:

309978

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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 states that: 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:

Guideline Reference:

Water Quality Criteria Report for Bifenthrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152577	Region 4
Hopper Creek

Pollutant:	Cyfluthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84832 has been replaced by LOE 310122 due to a reassessment of data using updated UCD Criterion.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152577, Cyfluthrin	Region 4
Hopper Creek

LOE ID:

310152

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 cyfluthrin is 0.2 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of cyfluthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152577, Cyfluthrin	Region 4
Hopper Creek

LOE ID:

310122

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152579	Region 4
Hopper Creek

Pollutant:	Cyhalothrin, Lambda
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84837 has been replaced by LOE 310554 due to a reassessment of data using updated UCD Criterion.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152579, Cyhalothrin, Lambda	Region 4
Hopper Creek

LOE ID:

310554

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: Surface waters 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:

The chronic criterion for lambda-cyhalothrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of lambda-cyhalothrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152579, Cyhalothrin, Lambda	Region 4
Hopper Creek

LOE ID:

310586

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Data for various Pollutants from the Ag Waiver Program, 2007-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152571	Region 4
Hopper Creek

Pollutant:	Cypermethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84838 has been replaced by LOE 310110 due to a reassessment of data using interim freshwater criterion.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152571, Cypermethrin	Region 4
Hopper Creek

LOE ID:

310110

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 cypermethrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of cypermethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Cypermethrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152571, Cypermethrin	Region 4
Hopper Creek

LOE ID:

309947

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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:

Guideline Reference:

Water Quality Criteria Report for Cypermethrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152578	Region 4
Hopper Creek

Pollutant:	Deltamethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84771 has been replaced by LOE 310251 due to a reassessment of data using updated USEPA Aquatic Life Benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152578, Deltamethrin	Region 4
Hopper Creek

LOE ID:

310251

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152578, Deltamethrin	Region 4
Hopper Creek

LOE ID:

310162

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152567	Region 4
Hopper Creek

Pollutant:	Dichlorvos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84775 has been replaced by LOE 310238 due to a reassessment of data using updated USEPA Aquatic Life Benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152567, Dichlorvos	Region 4
Hopper Creek

LOE ID:

310238

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152567, Dichlorvos	Region 4
Hopper Creek

LOE ID:

310344

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152568	Region 4
Hopper Creek

Pollutant:	Dicofol
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84776 has been replaced by LOE 310412 due to a reassessment of data using updated USEPA Aquatic Life Benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152568, Dicofol	Region 4
Hopper Creek

LOE ID:

310412

Pollutant:

Dicofol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Dicofol.

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 states that: 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 USEPA Aquatic Life Benchmark of 4.4 ug/L for a fish (chronic).

Guideline Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152568, Dicofol	Region 4
Hopper Creek

LOE ID:

310430

Pollutant:

Dicofol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Dicofol.

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 states that: 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 USEPA Aquatic Life Benchmark of 4.4 ug/L for a fish (chronic).

Guideline Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152573	Region 4
Hopper Creek

Pollutant:	Dimethoate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84784 has been replaced by LOE 310243 due to a reassessment of data using updated USEPA Aquatic Life Benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152573, Dimethoate	Region 4
Hopper Creek

LOE ID:

310243

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Dimethoate.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152573, Dimethoate	Region 4
Hopper Creek

LOE ID:

310206

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Dimethoate.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152581	Region 4
Hopper Creek

Pollutant:	Esfenvalerate/Fenvalerate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84814 & 84810 has been replaced by LOE 310213 due to a reassessment of data using updated USEPA Aquatic Life Benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152581, Esfenvalerate/Fenvalerate	Region 4
Hopper Creek

LOE ID:

310213

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 esfenvalerate is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of esfenvalerate were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Esfenvalerate

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152581, Esfenvalerate/Fenvalerate	Region 4
Hopper Creek

LOE ID:

310211

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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:

Guideline Reference:

Water Quality Criteria Report for Esfenvalerate

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152574	Region 4
Hopper Creek

Pollutant:	Ethoprop
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84815 has been replaced by LOE 310495 due to a reassessment of data using updated USEPA Aquatic Life Benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152574, Ethoprop	Region 4
Hopper Creek

LOE ID:

310495

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ethoprop.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152574, Ethoprop	Region 4
Hopper Creek

LOE ID:

310529

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ethoprop.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152580	Region 4
Hopper Creek

Pollutant:	Fenpropathrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84816 has been replaced by LOE 310653 due to a reassessment of data using updated USEPA Aquatic Life Benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152580, Fenpropathrin	Region 4
Hopper Creek

LOE ID:

310653

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152580, Fenpropathrin	Region 4
Hopper Creek

LOE ID:

310480

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152566	Region 4
Hopper Creek

Pollutant:	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 Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152566, Fenvalerate	Region 4
Hopper Creek

LOE ID:

310727

Pollutant:

Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Fenvalerate.

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 states that: 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 LC50 of 1.13 ug/L for fathead minnow, Pimephales promelas. (USEPA Office of Pesticide Programs Ecotoxicity database)

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152566, Fenvalerate	Region 4
Hopper Creek

LOE ID:

310465

Pollutant:

Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Fenvalerate.

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 states that: 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 LC50 of 1.13 ug/L for fathead minnow, Pimephales promelas. (USEPA Office of Pesticide Programs Ecotoxicity database)

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152572	Region 4
Hopper Creek

Pollutant:	Methidathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84835 has been replaced by LOE 310609 due to a reassessment of data using updated USEPA Aquatic Life Benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152572, Methidathion	Region 4
Hopper Creek

LOE ID:

310609

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Methidathion.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2009-02-06 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152572, Methidathion	Region 4
Hopper Creek

LOE ID:

310608

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Methidathion.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2009-02-06 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152582	Region 4
Hopper Creek

Pollutant:	Permethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84766 has been replaced by LOE 310804 due to a reassessment of data using updated UCD Criterion.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152582, Permethrin	Region 4
Hopper Creek

LOE ID:

310885

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 permethrin is 1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of permethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Permethrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152582, Permethrin	Region 4
Hopper Creek

LOE ID:

310804

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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:

Guideline Reference:

Water Quality Criteria Report for Permethrin

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152575	Region 4
Hopper Creek

Pollutant:	Phorate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84782 has been replaced by LOE 310964 due to a reassessment of data using updated USEPA Aquatic Life Benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152575, Phorate	Region 4
Hopper Creek

LOE ID:

310999

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Phorate.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.21 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152575, Phorate	Region 4
Hopper Creek

LOE ID:

310964

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Phorate.

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 states that: 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 USEPA Aquatic Life Benchmark of 0.21 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2008-01-05 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152576	Region 4
Hopper Creek

Pollutant:	Phosmet
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 84789 has been replaced by LOE 310830 due to a reassessment of data using updated UCD Criterion.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152576, Phosmet	Region 4
Hopper Creek

LOE ID:

310816

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Phosmet.

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 states that: 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 phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2009-02-06 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152576, Phosmet	Region 4
Hopper Creek

LOE ID:

310830

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Phosmet.

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 states that: 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 phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

The samples were collected between the dates of 2009-02-06 and 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	152569	Region 4
Hopper Creek

Pollutant:	Pyrethroids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 152569, Pyrethroids	Region 4
Hopper Creek

LOE ID:

311014

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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 summed ratios of the pyrethroid pesticides bifenthrin, cyfluthrin, cypermethrin, esfenvalerate, lambda-cyhalothrin, permethrin and their respective chronic concentration goals are not to exceed 1. If the freely dissolved concentrations of these pesticides were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.

Line of Evidence (LOE) for Decision ID 152569, Pyrethroids	Region 4
Hopper Creek

LOE ID:

311015

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP 2007-2009 data for Hopper Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

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 states that: 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:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: S04T_HOPP (Hopper Creek on at Hwy. 126).

Temporal Representation:

Data for this waterbody were collected over the date range 2008-01-05 to 2009-02-06

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):

Quality Assurance Project Plan from Ventura County Agricultural Irrigated Lands Group.


DECISION ID	69376	Region 4
Hopper Creek

Pollutant:	Sulfates
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2015
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. 2 lines of evidence are available in the administrative record to assess this pollutant. 11 of the 12 samples exceed the OBJECTIVE. 1 of the 4 samples exceed the OBJECTIVE. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the 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. 11 of 12 and 1 of 4 samples exceeded the OBJECTIVE and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 69376, Sulfates	Region 4
Hopper Creek

LOE ID:

84794

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 1 of 4 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 Hopper Creek 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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 69376, Sulfates	Region 4
Hopper Creek

LOE ID:

2105

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Twelve water samples, 11 samples exceeding. (SWRCB, 2003).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Basin Plan WQO: 600 mg/L.

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Limited. Hwy 126

Temporal Representation:

Quarterly sampling events, 2002-2003.

Environmental Conditions:

QAPP Information:

United Water Conservation District

QAPP Information Reference(s):


DECISION ID	69521	Region 4
Hopper Creek

Pollutant:	Total Dissolved Solids
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section 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. 10 of the 11 samples exceed the OBJECTIVE. 1 of the 4 samples exceed the OBJECTIVE. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 10 of 11 and 1 of 4 samples exceeded the OBJECTIVE and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 69521, Total Dissolved Solids	Region 4
Hopper Creek

LOE ID:

2104

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Eleven water samples, 10 samples exceeding (SWRCB, 2003).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Basin Plan WQO: 1,300 mg/L.

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Collected at Hwy. 126.

Temporal Representation:

Quarterly sampling events, 2002-2003.

Environmental Conditions:

QAPP Information:

United Water Conservation District

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 69521, Total Dissolved Solids	Region 4
Hopper Creek

LOE ID:

84803

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 1 of 4 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 Hopper Creek 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95839	Region 4
Hopper Creek

Pollutant:	Aldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95839, Aldrin	Region 4
Hopper Creek

LOE ID:

84799

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95780	Region 4
Hopper Creek

Pollutant:	Ammonia
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95780, Ammonia	Region 4
Hopper Creek

LOE ID:

84808

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95379	Region 4
Hopper Creek

Pollutant:	Azinphos-methyl (Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 1 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95379, Azinphos-methyl (Guthion)	Region 4
Hopper Creek

LOE ID:

84813

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 1 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:

Spatial Representation:

Data for this line of evidence for Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected on a single day 2/6/2009.

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	95601	Region 4
Hopper Creek

Pollutant:	Chlordane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95601, Chlordane	Region 4
Hopper Creek

LOE ID:

84821

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95216	Region 4
Hopper Creek

Pollutant:	Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 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 4 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 4 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95216, Chloride	Region 4
Hopper Creek

LOE ID:

84825

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95602	Region 4
Hopper Creek

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95602, Chlorpyrifos	Region 4
Hopper Creek

LOE ID:

84828

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	98977	Region 4
Hopper Creek

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the 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 lines of evidence are available in the administrative record to assess this pollutant. 0 of 0 sample 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 0 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 98977, DDD (Dichlorodiphenyldichloroethane)	Region 4
Hopper Creek

LOE ID:

84844

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 0 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 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	99699	Region 4
Hopper Creek

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 lines of evidence are available in the administrative record to assess this pollutant. 0 of 0 sample 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 0 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 99699, DDE (Dichlorodiphenyldichloroethylene)	Region 4
Hopper Creek

LOE ID:

96209

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for DDE(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:

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 DDE-4,4' criteria for the protection of human health from 30-day average fish consumption component of water contact recreation (REC-1) use is 0.00059 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95103	Region 4
Hopper Creek

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 sample 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 sample exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95103, DDT (Dichlorodiphenyltrichloroethane)	Region 4
Hopper Creek

LOE ID:

84769

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95603	Region 4
Hopper Creek

Pollutant:	Dacthal
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the 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 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95603, Dacthal	Region 4
Hopper Creek

LOE ID:

84842

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95268	Region 4
Hopper Creek

Pollutant:	Demeton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. 0 of 4 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95268, Demeton	Region 4
Hopper Creek

LOE ID:

84772

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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:

Spatial Representation:

Data for this line of evidence for Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95604	Region 4
Hopper Creek

Pollutant:	Diazinon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95604, Diazinon	Region 4
Hopper Creek

LOE ID:

84773

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95840	Region 4
Hopper Creek

Pollutant:	Dieldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95840, Dieldrin	Region 4
Hopper Creek

LOE ID:

84777

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95665	Region 4
Hopper Creek

Pollutant:	Disulfoton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95665, Disulfoton	Region 4
Hopper Creek

LOE ID:

84786

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 µg/L.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95666	Region 4
Hopper Creek

Pollutant:	Endosulfan
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95666, Endosulfan	Region 4
Hopper Creek

LOE ID:

84791

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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:

Spatial Representation:

Data for this line of evidence for Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95667	Region 4
Hopper Creek

Pollutant:	Endosulfan sulfate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95667, Endosulfan sulfate	Region 4
Hopper Creek

LOE ID:

84793

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 µg/L.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95725	Region 4
Hopper Creek

Pollutant:	Endrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95725, Endrin	Region 4
Hopper Creek

LOE ID:

84801

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	79693	Region 4
Hopper Creek

Pollutant:	Endrin aldehyde
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. 0 of 4 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the waterbody-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 79693, Endrin aldehyde	Region 4
Hopper Creek

LOE ID:

96168

Pollutant:

Endrin aldehyde

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95893	Region 4
Hopper Creek

Pollutant:	Heptachlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95893, Heptachlor	Region 4
Hopper Creek

LOE ID:

84819

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95894	Region 4
Hopper Creek

Pollutant:	Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95894, Heptachlor epoxide	Region 4
Hopper Creek

LOE ID:

84823

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95727	Region 4
Hopper Creek

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95727, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 4
Hopper Creek

LOE ID:

84829

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95728	Region 4
Hopper Creek

Pollutant:	Malathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95728, Malathion	Region 4
Hopper Creek

LOE ID:

84834

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95779	Region 4
Hopper Creek

Pollutant:	Methoxychlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 4 samples exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95779, Methoxychlor	Region 4
Hopper Creek

LOE ID:

84836

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 µg/L.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95326	Region 4
Hopper Creek

Pollutant:	Methyl Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. 0 of 4 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95326, Methyl Parathion	Region 4
Hopper Creek

LOE ID:

84840

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95378	Region 4
Hopper Creek

Pollutant:	Mirex
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. 0 of 4 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95378, Mirex	Region 4
Hopper Creek

LOE ID:

84841

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 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:

Spatial Representation:

Data for this line of evidence for Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95104	Region 4
Hopper Creek

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 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 5 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 5 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95104, Oxygen, Dissolved	Region 4
Hopper Creek

LOE ID:

84846

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 5 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 12/19/2007-2/6/2009.

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	95485	Region 4
Hopper Creek

Pollutant:	Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 1 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 1 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95485, Parathion	Region 4
Hopper Creek

LOE ID:

84847

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 1 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:

Spatial Representation:

Data for this line of evidence for Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected on a single day 2/6/2009.

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	95160	Region 4
Hopper Creek

Pollutant:	Temperature, water
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 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 5 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 5 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95160, Temperature, water	Region 4
Hopper Creek

LOE ID:

84797

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 5 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 12/19/2007-2/6/2009.

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	95044	Region 4
Hopper Creek

Pollutant:	Toxaphene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 0 sample 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample exceeded the CRITERION and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95044, Toxaphene	Region 4
Hopper Creek

LOE ID:

84805

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene. 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 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95381	Region 4
Hopper Creek

Pollutant:	Toxicity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.6 of the Listing Policy. Under section 3.6 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 1 sample exceeded the GUIDELINE. 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 1 sample exceeded the GUIDELINE and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95381, Toxicity	Region 4
Hopper Creek

LOE ID:

84811

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One sample was collected to evaluate water toxicity. None of the samples exhibited significant toxicity. The toxicity tests included survival and reproduction of Ceriodaphnia dubia, survival and growth of Pimephales promelas, and cell count of Selanastrum capricornatum.

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.

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 samples were collected at Hopper Creek on at Hwy. 126.

Temporal Representation:

The sample was collected in January 2008.

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):


DECISION ID	99961	Region 4
Hopper Creek

Pollutant:	alpha.-BHC (Benzenehexachloride or alpha-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. 0 of 4 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 99961, alpha.-BHC (Benzenehexachloride or alpha-HCH)	Region 4
Hopper Creek

LOE ID:

96182

Pollutant:

alpha.-BHC (Benzenehexachloride or alpha-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for BHC, alpha.

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 BHC, alpha criteria for the protection of human health from 30-day average fish consumption component of water contact recreation (REC-1) use is 0.013 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	99657	Region 4
Hopper Creek

Pollutant:	beta-BHC (Benzenehexachloride or beta-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 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. 0 of 4 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 99657, beta-BHC (Benzenehexachloride or beta-HCH)	Region 4
Hopper Creek

LOE ID:

96195

Pollutant:

beta-BHC (Benzenehexachloride or beta-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Ag waiver data for Boulder Creek (Ventura County) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for BHC, beta.

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 BHC, beta criteria for the protection of human health from30-day average fish consumption component of water contact recreation (REC-1) use is 0.046 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 1/5/2008-2/6/2009.

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	95382	Region 4
Hopper Creek

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. 3 lines of evidence are available in the administrative record to assess this pollutant. 0 of 5 samples exceeded the OBJECTIVE. 0 of 5 samples exceeded the OBJECTIVE. 0 of 5 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 5, 0 of 5, and 0 of 5 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95382, pH	Region 4
Hopper Creek

LOE ID:

84767

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 5 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 12/19/2007-2/6/2009.

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 95382, pH	Region 4
Hopper Creek

LOE ID:

84780

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 5 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 12/19/2007-2/6/2009.

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 95382, pH	Region 4
Hopper Creek

LOE ID:

84779

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed Agwaiver data for Hopper Creek to determine beneficial use support and results are as follows: 0 of 5 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 Hopper Creek was collected at 1 monitoring site [ Hopper Creek on at Hwy. 126 - S04T_HOPP]

Temporal Representation:

Data was collected over the time period 12/19/2007-2/6/2009.

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.