Final California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name: McGowan Ditch
Water Body ID: CAR3051003020100620223644
Water Body Type: River & Stream
 
DECISION ID
129965
Region 3     
McGowan Ditch
 
Pollutant: Alachlor
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55078 and 55083 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

Zero of the nine samples exceed the evaluation guidelines for protection of drinking water (The California Maximum Contaminant Level).

These sample sizes are 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129965, Alachlor
Region 3     
McGowan Ditch
 
LOE ID: 225140
 
Pollutant: Alachlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Alachlor.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Alachlor is the USEPA Aquatic Life Benchmark of 1.64 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129965, Alachlor
Region 3     
McGowan Ditch
 
LOE ID: 225120
 
Pollutant: Alachlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Alachlor.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Alachlor is the USEPA Aquatic Life Benchmark of 1.64 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129965, Alachlor
Region 3     
McGowan Ditch
 
LOE ID: 55077
 
Pollutant: Alachlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for ALACHLOR.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for Alachlor is 0.002 mg/L (Title 22 of the California Code of Regulations ).
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
129952
Region 3     
McGowan Ditch
 
Pollutant: Atrazine
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55085 and 55086 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

Zero of the nine samples exceed the evaluation guidelines for protection of drinking water (The California Maximum Contaminant Level).

These sample sizes are 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129952, Atrazine
Region 3     
McGowan Ditch
 
LOE ID: 224909
 
Pollutant: Atrazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Atrazine.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of <1 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129952, Atrazine
Region 3     
McGowan Ditch
 
LOE ID: 224930
 
Pollutant: Atrazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Atrazine.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of <1 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129952, Atrazine
Region 3     
McGowan Ditch
 
LOE ID: 55084
 
Pollutant: Atrazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for ATRAZINE.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for atrazine is 0.001 mg/L (Title 22 of the California Code of Regulations ).
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
129960
Region 3     
McGowan Ditch
 
Pollutant: Butylate
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 54968 and 54973 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129960, Butylate
Region 3     
McGowan Ditch
 
LOE ID: 225007
 
Pollutant: Butylate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Butylate.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Butylate is the USEPA Aquatic Life Benchmark of 105 ug/L for a fish (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129960, Butylate
Region 3     
McGowan Ditch
 
LOE ID: 224971
 
Pollutant: Butylate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Butylate.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Butylate is the USEPA Aquatic Life Benchmark of 105 ug/L for a fish (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129953
Region 3     
McGowan Ditch
 
Pollutant: Dacthal
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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:
 
 
Line of Evidence (LOE) for Decision ID 129953, Dacthal
Region 3     
McGowan Ditch
 
LOE ID: 225066
 
Pollutant: Dacthal
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Dacthal.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Dacthal is the USEPA Aquatic Life Benchmark of >1100 ug/L for a nonvascular plant (acute) and vascular plant (acute). The benchmark was derived from a \greater-than\" value (for example, > 265,000) and may overestimate toxicity."
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129953, Dacthal
Region 3     
McGowan Ditch
 
LOE ID: 225087
 
Pollutant: Dacthal
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Dacthal.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Dacthal is the USEPA Aquatic Life Benchmark of >1100 ug/L for a nonvascular plant (acute) and vascular plant (acute). The benchmark was derived from a \greater-than\" value (for example, > 265,000) and may overestimate toxicity."
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129967
Region 3     
McGowan Ditch
 
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55051, 55056, 55057 and 55058 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129967, Deltamethrin
Region 3     
McGowan Ditch
 
LOE ID: 224853
 
Pollutant: Deltamethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Deltamethrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Deltamethrin is the USEPA Aquatic Life Benchmark of 0.0041 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129967, Deltamethrin
Region 3     
McGowan Ditch
 
LOE ID: 225148
 
Pollutant: Deltamethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Deltamethrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Deltamethrin is the USEPA Aquatic Life Benchmark of 0.0041 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129961
Region 3     
McGowan Ditch
 
Pollutant: Ethalfluralin
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55079 and 55080 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129961, Ethalfluralin
Region 3     
McGowan Ditch
 
LOE ID: 225021
 
Pollutant: Ethalfluralin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Ethalfluralin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Ethalfluralin is the USEPA Aquatic Life Benchmark of 0.4 ug/L for a fish (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129961, Ethalfluralin
Region 3     
McGowan Ditch
 
LOE ID: 224862
 
Pollutant: Ethalfluralin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Ethalfluralin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Ethalfluralin is the USEPA Aquatic Life Benchmark of 0.4 ug/L for a fish (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129968
Region 3     
McGowan Ditch
 
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: This pollutant is being considered for placement on the CWA section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) List.

Four lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55088 and 55089 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

One of the three sediment samples exceeded the evaluation guidelines for aquatic life protection in sediment.

These sample sizes are 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of the three sediment samples exceed the evaluation guidelines. However, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129968, Fenpropathrin
Region 3     
McGowan Ditch
 
LOE ID: 55082
 
Pollutant: Fenpropathrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Fenpropathrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for fenpropathrin is the median lethal concentration (LC50) of 1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1 ug/g is the geometric mean of LC50 values for fenpropathrin from Ding et al. ( 2011).
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 129968, Fenpropathrin
Region 3     
McGowan Ditch
 
LOE ID: 225443
 
Pollutant: Fenpropathrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Fenpropathrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.06 ug/L for a fish (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129968, Fenpropathrin
Region 3     
McGowan Ditch
 
LOE ID: 225440
 
Pollutant: Fenpropathrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Fenpropathrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.06 ug/L for a fish (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129968, Fenpropathrin
Region 3     
McGowan Ditch
 
LOE ID: 55081
 
Pollutant: Fenpropathrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Fenpropathrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for fenpropathrin is the median lethal concentration (LC50) of 1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1 ug/g is the geometric mean of LC50 values for fenpropathrin from Ding et al. ( 2011).
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
 
DECISION ID
129969
Region 3     
McGowan Ditch
 
Pollutant: Hexazinone
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 54978 and 54979 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines. However, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129969, Hexazinone
Region 3     
McGowan Ditch
 
LOE ID: 225190
 
Pollutant: Hexazinone
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Hexazinone.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Hexazinone is the USEPA Aquatic Life Benchmark of 7 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129969, Hexazinone
Region 3     
McGowan Ditch
 
LOE ID: 225189
 
Pollutant: Hexazinone
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Hexazinone.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Hexazinone is the USEPA Aquatic Life Benchmark of 7 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129957
Region 3     
McGowan Ditch
 
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 54989 and 54994 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

Zero of nine samples exceeded the evaluation guidelines set to protect for municipal and domestic supply beneficial use.

These sample sizes are 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129957, Methidathion
Region 3     
McGowan Ditch
 
LOE ID: 225423
 
Pollutant: Methidathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Methidathion.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129957, Methidathion
Region 3     
McGowan Ditch
 
LOE ID: 225382
 
Pollutant: Methidathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Methidathion.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129957, Methidathion
Region 3     
McGowan Ditch
 
LOE ID: 54988
 
Pollutant: Methidathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for METHIDATHION.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for methidathion is 0.7 µg/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, and 20% relative source contribution from drinking water.  An additional uncertainty factor of 10 is used for Class C carcinogens.
Guideline Reference: IRIS Database Calculations (summary)
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
129962
Region 3     
McGowan Ditch
 
Pollutant: Metolachlor
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines. However, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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:
 
 
Line of Evidence (LOE) for Decision ID 129962, Metolachlor
Region 3     
McGowan Ditch
 
LOE ID: 225470
 
Pollutant: Metolachlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Metolachlor.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Metolachlor is the USEPA Aquatic Life Benchmark of 1 ug/L for an invertebrate (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129962, Metolachlor
Region 3     
McGowan Ditch
 
LOE ID: 225445
 
Pollutant: Metolachlor
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Metolachlor.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Metolachlor is the USEPA Aquatic Life Benchmark of 1 ug/L for an invertebrate (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129954
Region 3     
McGowan Ditch
 
Pollutant: Molinate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55005 and 55010 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

Zero of nine samples exceeded the evaluation guidelines set to protect for municipal and domestic supply beneficial use.

These sample sizes are 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129954, Molinate
Region 3     
McGowan Ditch
 
LOE ID: 55004
 
Pollutant: Molinate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for MOLINATE.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for molinate is 20 ug/L (Title 22 of the California Code of Regulations).
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 129954, Molinate
Region 3     
McGowan Ditch
 
LOE ID: 225199
 
Pollutant: Molinate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Molinate.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Molinate is the USEPA Aquatic Life Benchmark of 105 ug/L for a fish (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129954, Molinate
Region 3     
McGowan Ditch
 
LOE ID: 225196
 
Pollutant: Molinate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Molinate.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Molinate is the USEPA Aquatic Life Benchmark of 105 ug/L for a fish (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129963
Region 3     
McGowan Ditch
 
Pollutant: Napropamide
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55011 and 55012 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129963, Napropamide
Region 3     
McGowan Ditch
 
LOE ID: 225281
 
Pollutant: Napropamide
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Napropamide.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Napropamide is the USEPA Aquatic Life Benchmark of 1100 ug/L for a invertebrate (acute) and fish (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129963, Napropamide
Region 3     
McGowan Ditch
 
LOE ID: 225279
 
Pollutant: Napropamide
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Napropamide.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Napropamide is the USEPA Aquatic Life Benchmark of 1100 ug/L for a invertebrate (acute) and fish (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129964
Region 3     
McGowan Ditch
 
Pollutant: Pendimethalin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines. However, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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:
 
 
Line of Evidence (LOE) for Decision ID 129964, Pendimethalin
Region 3     
McGowan Ditch
 
LOE ID: 225431
 
Pollutant: Pendimethalin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Pendimethalin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129964, Pendimethalin
Region 3     
McGowan Ditch
 
LOE ID: 225428
 
Pollutant: Pendimethalin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Pendimethalin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
130667
Region 3     
McGowan Ditch
 
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: This pollutant is being considered for placement on the CWA section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 at least one line of evidence is necessary to assess listing status, but under section 3.6 at least two lines of evidence are necessary to assess listing status and the pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the section 303(d) List.

Four lines of evidence are available in the administrative record to assess this pollutant. Zero of three sediment samples exceed the evaluation guideline and zero of zero water samples (fraction total) exceed the evaluation guideline applied to protect for aquatic life beneficial uses. Note, the water sample results 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. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the three sediment samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. One of the one water samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 130667, Permethrin
Region 3     
McGowan Ditch
 
LOE ID: 55018
 
Pollutant: Permethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Permethrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 130667, Permethrin
Region 3     
McGowan Ditch
 
LOE ID: 55020
 
Pollutant: Permethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for PERMETHRIN. Nine sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of permethrin does not exceed 0.002 ug/L and if the 1-h average concentration does not exceed 0.01 ug/L. For this assessment, the 4-day average concentration was used. Mixtures of permethrin and other pyrethroids should be considered in an additive manner. (Fojut et al. 2012)
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 130667, Permethrin
Region 3     
McGowan Ditch
 
LOE ID: 55021
 
Pollutant: Permethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for PERMETHRIN. Nine sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of permethrin does not exceed 0.002 ug/L and if the 1-h average concentration does not exceed 0.01 ug/L. For this assessment, the 4-day average concentration was used. Mixtures of permethrin and other pyrethroids should be considered in an additive manner. (Fojut et al. 2012)
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 130667, Permethrin
Region 3     
McGowan Ditch
 
LOE ID: 55019
 
Pollutant: Permethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Permethrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
 
DECISION ID
129966
Region 3     
McGowan Ditch
 
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55026 and 55027 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

Zero of nine samples exceeded the evaluation guidelines set to protect for municipal and domestic supply beneficial use.

These sample sizes are 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129966, Phosmet
Region 3     
McGowan Ditch
 
LOE ID: 225503
 
Pollutant: Phosmet
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Phosmet.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Phosmet is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129966, Phosmet
Region 3     
McGowan Ditch
 
LOE ID: 225605
 
Pollutant: Phosmet
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Phosmet.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Phosmet is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129966, Phosmet
Region 3     
McGowan Ditch
 
LOE ID: 55028
 
Pollutant: Phosmet
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for PHOSMET.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for phosmet is 140 µg/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, and 20% relative source contribution from drinking water.  An additional uncertainty factor of 10 is used for Class C carcinogens.
Guideline Reference: IRIS Database Calculations (summary)
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
129958
Region 3     
McGowan Ditch
 
Pollutant: Prometryn
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55029 and 55030 have been removed from this decision and replaced with new LOEs that assess the data using the UC Davis aquatic life criteria.

Zero of the nine samples exceed the evaluation guidelines for aquatic life protection (UC Davis Aquatic Life Criteria).

Zero of nine samples exceeded the evaluation guidelines set to protect for municipal and domestic supply beneficial use.

These sample sizes are 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129958, Prometryn
Region 3     
McGowan Ditch
 
LOE ID: 225535
 
Pollutant: Prometryn
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the water quality threshold for Prometryn.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Prometryn does not exceed 0.562 ug/L in the water column more than once every three years on average (Bower, et al. 2017).
Guideline Reference: Water Quality Criteria Report for Prometryn Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis.
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129958, Prometryn
Region 3     
McGowan Ditch
 
LOE ID: 55035
 
Pollutant: Prometryn
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for PROMETRYN.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for prometryn is 28 µg/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, and 20% relative source contribution from drinking water.  An additional uncertainty factor of 10 is used for Class C carcinogens.
Guideline Reference: IRIS Database Calculations (summary)
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 129958, Prometryn
Region 3     
McGowan Ditch
 
LOE ID: 225533
 
Pollutant: Prometryn
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the water quality threshold for Prometryn.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Prometryn does not exceed 0.562 ug/L in the water column more than once every three years on average (Bower, et al. 2017).
Guideline Reference: Water Quality Criteria Report for Prometryn Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis.
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129970
Region 3     
McGowan Ditch
 
Pollutant: Propiconazole
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55038 and 55043 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129970, Propiconazole
Region 3     
McGowan Ditch
 
LOE ID: 225554
 
Pollutant: Propiconazole
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Propiconazole.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Propiconazole is the USEPA Aquatic Life Benchmark of 21 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129970, Propiconazole
Region 3     
McGowan Ditch
 
LOE ID: 225563
 
Pollutant: Propiconazole
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Propiconazole.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Propiconazole is the USEPA Aquatic Life Benchmark of 21 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129955
Region 3     
McGowan Ditch
 
Pollutant: Simazine
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55046 and 55047 have been removed from this decision and replaced with new LOEs that assess the data using the USEPA aquatic life benchmarks.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

Zero of nine samples exceeded the evaluation guidelines set to protect for municipal and domestic supply beneficial use.

These sample sizes are 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129955, Simazine
Region 3     
McGowan Ditch
 
LOE ID: 225574
 
Pollutant: Simazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Simazine.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129955, Simazine
Region 3     
McGowan Ditch
 
LOE ID: 225578
 
Pollutant: Simazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Simazine.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129955, Simazine
Region 3     
McGowan Ditch
 
LOE ID: 55045
 
Pollutant: Simazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for SIMAZINE.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for simazine is 0.004 mg/L (Title 22 of the California Code of Regulations).
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
129971
Region 3     
McGowan Ditch
 
Pollutant: Thiobencarb
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant.

Zero of the eight samples exceed the evaluation guidelines for aquatic life protection (USEPA benchmark).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the evaluation guidelines. However, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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:
 
 
Line of Evidence (LOE) for Decision ID 129971, Thiobencarb
Region 3     
McGowan Ditch
 
LOE ID: 225496
 
Pollutant: Thiobencarb
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Thiobencarb.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Thiobencarb is the USEPA Aquatic Life Benchmark of 1 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129971, Thiobencarb
Region 3     
McGowan Ditch
 
LOE ID: 225600
 
Pollutant: Thiobencarb
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Thiobencarb.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Thiobencarb is the USEPA Aquatic Life Benchmark of 1 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129956
Region 3     
McGowan Ditch
 
Pollutant: Trifluralin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant. LOEs 55070 and 55071 have been removed from this decision and replaced with new LOEs that assess the data using the UC Davis aquatic life criteria.

Zero of the nine samples exceed the evaluation guidelines for aquatic life protection (UC Davis Aquatic Life Criteria).

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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA 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 129956, Trifluralin
Region 3     
McGowan Ditch
 
LOE ID: 225520
 
Pollutant: Trifluralin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the water quality threshold for Trifluralin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Trifluralin does not exceed 0.33 ug/L in the water column more than once every three years on average (Bower, et al. 2017).
Guideline Reference: Water Quality Criteria Report for Trifluralin Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology University of California, Davis.
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129956, Trifluralin
Region 3     
McGowan Ditch
 
LOE ID: 225521
 
Pollutant: Trifluralin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the water quality threshold for Trifluralin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Trifluralin does not exceed 0.33 ug/L in the water column more than once every three years on average (Bower, et al. 2017).
Guideline Reference: Water Quality Criteria Report for Trifluralin Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology University of California, Davis.
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
129959
Region 3     
McGowan Ditch
 
Pollutant: Oxyfluorfen
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: No Source Analysis Available
Expected TMDL Completion Date: 2035
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence (LOEs) are available in the administrative record to assess this pollutant.

Two of the nine samples exceed the evaluation guidelines for aquatic life protection (UC Davis Aquatic Life Criteria).

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Two of the nine samples exceed the evaluation guidelines and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) List because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 129959, Oxyfluorfen
Region 3     
McGowan Ditch
 
LOE ID: 225346
 
Pollutant: Oxyfluorfen
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 9 samples exceeded the water quality threshold for Oxyfluorfen.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Oxyfluorfen does not exceed 0.14 ug/L in the water column more than once every three years on average (Bower, et al. 2017).
Guideline Reference: Water quality criteria report for Oxyfluorfen. Phase III: application of the pesticide water quality criteria methodology.
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 129959, Oxyfluorfen
Region 3     
McGowan Ditch
 
LOE ID: 225342
 
Pollutant: Oxyfluorfen
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 9 samples exceeded the water quality threshold for Oxyfluorfen.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Oxyfluorfen does not exceed 0.14 ug/L in the water column more than once every three years on average (Bower, et al. 2017).
Guideline Reference: Water quality criteria report for Oxyfluorfen. Phase III: application of the pesticide water quality criteria methodology.
 
Spatial Representation: The samples were collected at 1 monitoring site (305MDD)
Temporal Representation: The samples were collected between the dates of 2008-01-06 and 2009-10-28
Environmental Conditions:
QAPP Information: QAPP not required
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
82695
Region 3     
McGowan Ditch
 
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: No new data were assessed.

This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

The pollutant name was changed from ¿Nitrogen, ammonia (Total Ammonia)' to ¿Ammonia¿ in the 2014 assessment cycle.

One line of evidence is available in the administrative record to assess this pollutant. Neither of the 2 samples exceed the Evaluation Guideline (EPA's Lifetime Health advisory level, 2006) applied to protect the Municipal & Domestic Supply beneficial use. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Neither of the 2 samples exceed the Evaluation Guideline (EPA's Lifetime Health advisory level, 2006) applied to protect the Municipal & Domestic Supply beneficial use and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 82695, Ammonia
Region 3     
McGowan Ditch
 
LOE ID: 17832
 
Pollutant: Ammonia as Nitrogen
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Ammonia As N, Total.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: USEPA Health Advisory 2006 Edition of the Drinking Water Standards and Health Advisories (EPA 822-R-06-013, 2006).
Objective/Criterion Reference: 2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
 
Evaluation Guideline: EPA's Lifetime Health advisory level for total ammonia is 30.0 mg/L as stated on page 8 of the 2006 edition of the drinking water standards and health advisories. This Advisory Level is defined as "the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure."
Guideline Reference: 2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
 
DECISION ID
82114
Region 3     
McGowan Ditch
 
Pollutant: Bifenthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Four lines of evidence are available in the administrative record to assess this pollutant. One of the three sediment sample exceed the evaluation guideline (Amweg and Weston (2007) both used to interpret the narrative water quality objective for aquatic life. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1.

Note that none of the water sample results are used in the assessment because the results were reported a ¿non detect¿ (or less than the reporting limit) but the laboratory reporting limit was above the evaluation guideline (Fojut et al. 2012). Therefore it is possible for the true concentration to be higher than the evaluation guideline but that cannot be determined.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of the three sediment samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 82114, Bifenthrin
Region 3     
McGowan Ditch
 
LOE ID: 54967
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for BIFENTHRIN. Nine sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Bifenthrin does not exceed 0.0006 ug/L.
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82114, Bifenthrin
Region 3     
McGowan Ditch
 
LOE ID: 54965
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Bifenthrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of three toxicity LC50 values from Amweg et al. (2005) and one toxicity LC50 value from Amweg and Weston (2007).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82114, Bifenthrin
Region 3     
McGowan Ditch
 
LOE ID: 55087
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Bifenthrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of three toxicity LC50 values from Amweg et al. (2005) and one toxicity LC50 value from Amweg and Weston (2007).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82114, Bifenthrin
Region 3     
McGowan Ditch
 
LOE ID: 54966
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for BIFENTHRIN. Nine sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Bifenthrin does not exceed 0.0006 ug/L.
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82795
Region 3     
McGowan Ditch
 
Pollutant: Carbaryl
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guidelines for aquatic life protection and drinking water. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 82795, Carbaryl
Region 3     
McGowan Ditch
 
LOE ID: 54975
 
Pollutant: Carbaryl
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for CARBARYL.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA national ambient water quality criteria for freshwater aquatic life instantaneous maximum for carbaryl is 0.02 µg/L.
Guideline Reference: Compilation of Water Quality Goals
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82795, Carbaryl
Region 3     
McGowan Ditch
 
LOE ID: 54974
 
Pollutant: Carbaryl
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for CARBARYL.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA drinking water health advisory for carbaryl is 40 µg/L.
Guideline Reference: Compilation of Water Quality Goals
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82795, Carbaryl
Region 3     
McGowan Ditch
 
LOE ID: 54976
 
Pollutant: Carbaryl
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for CARBARYL.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA national ambient water quality criteria for freshwater aquatic life instantaneous maximum for carbaryl is 0.02 µg/L.
Guideline Reference: Compilation of Water Quality Goals
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82796
Region 3     
McGowan Ditch
 
Pollutant: Carbofuran
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guidelines for aquatic life protection (USEPA National Recommended Water Quality Criteria) and drinking water (California Maximum Contaminant Level). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 82796, Carbofuran
Region 3     
McGowan Ditch
 
LOE ID: 54983
 
Pollutant: Carbofuran
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for CARBOFURAN.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA national ambient water quality criteria for freshwater aquatic life instantaneous maximum for carbofuran is 0.5 µg/L.
Guideline Reference: Hazard Assessment of the Insecticide Carbofuran to Aquatic Organisms in the Sacramento River System
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82796, Carbofuran
Region 3     
McGowan Ditch
 
LOE ID: 54977
 
Pollutant: Carbofuran
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for CARBOFURAN.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for carbofuran is 18 mg/L (Title 22 of the California Code of Regulations).
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82796, Carbofuran
Region 3     
McGowan Ditch
 
LOE ID: 54982
 
Pollutant: Carbofuran
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for CARBOFURAN.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA national ambient water quality criteria for freshwater aquatic life instantaneous maximum for carbofuran is 0.5 µg/L.
Guideline Reference: Hazard Assessment of the Insecticide Carbofuran to Aquatic Organisms in the Sacramento River System
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82632
Region 3     
McGowan Ditch
 
Pollutant: Chlorothalonil
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guideline for drinking water (2006 USEPA Drinking Water Standards and Health Advisories). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82632, Chlorothalonil
Region 3     
McGowan Ditch
 
LOE ID: 54984
 
Pollutant: Chlorothalonil
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Chlorothalonil.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: According to the 2006 USEPA Drinking Water Standards and Health Advisories, the Ten-day Health Advisory for Chlorothalonil is 200 ug/L.
Guideline Reference: 2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
81572
Region 3     
McGowan Ditch
 
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 section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Five lines of evidence are available in the administrative record to assess this pollutant. Zero of nine water samples exceeded the aquatic life evaluation guideline (Siepmann and Finlayson 2000). Zero of nine samples exceeded the USEPA drinking water health advisory. Zero of three sediment samples exceeded the aquatic life evaluation guideline (Amweg and Weston, 2007). 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 supported using table 3.1.

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

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. No samples exceeded the aquatic life evaluation guideline (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005). This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 81572, Chlorpyrifos
Region 3     
McGowan Ditch
 
LOE ID: 54985
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Chlorpyrifos.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for chlorpyrifos is the median lethal concentration (LC50) of 1.77 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Amweg and Weston, 2007).
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 81572, Chlorpyrifos
Region 3     
McGowan Ditch
 
LOE ID: 54990
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Chlorpyrifos.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for chlorpyrifos is the median lethal concentration (LC50) of 1.77 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Amweg and Weston, 2007).
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 81572, Chlorpyrifos
Region 3     
McGowan Ditch
 
LOE ID: 54991
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for CHLORPYRIFOS.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000).
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 81572, Chlorpyrifos
Region 3     
McGowan Ditch
 
LOE ID: 54993
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for CHLORPYRIFOS.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA drinking water health advisory for chlorpyrifos is 2 µg/L.
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 81572, Chlorpyrifos
Region 3     
McGowan Ditch
 
LOE ID: 54992
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for CHLORPYRIFOS.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000).
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82172
Region 3     
McGowan Ditch
 
Pollutant: Cyfluthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the three sediment sample exceed the evaluation guideline (Amweg et al., 2005) used to interpret the narrative water quality objective for aquatic life. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the three sediment sample exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82172, Cyfluthrin
Region 3     
McGowan Ditch
 
LOE ID: 54999
 
Pollutant: Cyfluthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Cyfluthrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82172, Cyfluthrin
Region 3     
McGowan Ditch
 
LOE ID: 54998
 
Pollutant: Cyfluthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Cyfluthrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
 
DECISION ID
82115
Region 3     
McGowan Ditch
 
Pollutant: Cyhalothrin, Lambda
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Four lines of evidence are available in the administrative record to assess this pollutant. Zero of the three sediment sample exceed the evaluation guideline (Amweg and Weston (2007) both used to interpret the narrative water quality objective for aquatic life. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1.

Note that none of the water sample results are used in the assessment because the results were reported a ¿non detect¿ (or less than the reporting limit) but the laboratory reporting limit was above the evaluation guideline (Fojut et al. 2012). Therefore it is possible for the true concentration to be higher than the evaluation guideline but that cannot be determined.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the three sediment samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 82115, Cyhalothrin, Lambda
Region 3     
McGowan Ditch
 
LOE ID: 55001
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Cyhalothrin, lambda, total.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82115, Cyhalothrin, Lambda
Region 3     
McGowan Ditch
 
LOE ID: 55000
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Cyhalothrin, lambda, total.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82115, Cyhalothrin, Lambda
Region 3     
McGowan Ditch
 
LOE ID: 55006
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Cyhalothrin, lambda, total. Nine sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Cyhalothrin, lambda, total does not exceed 0.0005 ug/L.
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82115, Cyhalothrin, Lambda
Region 3     
McGowan Ditch
 
LOE ID: 55007
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Cyhalothrin, lambda, total. Nine sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Cyhalothrin, lambda, total does not exceed 0.0005 ug/L.
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82170
Region 3     
McGowan Ditch
 
Pollutant: Cypermethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Four lines of evidence are available in the administrative record to assess this pollutant. Zero of the three sediment sample exceed the evaluation guideline (Maund et al., 2002) both used to interpret the narrative water quality objective for aquatic life. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1.

Note that none of the water sample results are used in the assessment because the results were reported a ¿non detect¿ (or less than the reporting limit) but the laboratory reporting limit was above the evaluation guideline (Fojut et al. 2012). Therefore it is possible for the true concentration to be higher than the evaluation guideline but that cannot be determined.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the three sediment samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 82170, Cypermethrin
Region 3     
McGowan Ditch
 
LOE ID: 55015
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for CYPERMETHRIN. Nine sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Cypermethrin; Cypermethrin, total does not exceed 0.0002 ug/L.
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82170, Cypermethrin
Region 3     
McGowan Ditch
 
LOE ID: 55014
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for CYPERMETHRIN. Nine sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Cypermethrin; Cypermethrin, total does not exceed 0.0002 ug/L.
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82170, Cypermethrin
Region 3     
McGowan Ditch
 
LOE ID: 55009
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Cypermethrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al. (2002).
Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82170, Cypermethrin
Region 3     
McGowan Ditch
 
LOE ID: 55008
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Cypermethrin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al. (2002).
Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
 
DECISION ID
82748
Region 3     
McGowan Ditch
 
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 section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Eleven lines of evidence are available in the administrative record to assess this pollutant. The single water sample exceed the evaluation guideline (California Toxics Rule, 2000) and one of the six sediment samples exceed the evaluation guideline (MacDonald et al. 2000) used to interpret the narrative water quality objective for aquatic life. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.


Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification to add this water segment-pollutant combination from the section 303(d) list.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. The single water sample exceed the evaluation guideline (California Toxics Rule, 2000) and one of the six sediment samples exceed the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55060
 
Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for DDT, Total.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for total DDTs is 572 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55048
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for DDT. Data assessed were suspended sediment samples isolated from the whole water sample.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDT is 62.9 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-2/16/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55062
 
Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for DDT, Total.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for total DDTs is 572 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55055
 
Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for DDT, Total. Data assessed were suspended sediment samples isolated from the whole water sample.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for total DDTs is 572 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-2/16/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55061
 
Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for DDT, Total. Data assessed were suspended sediment samples isolated from the whole water sample.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for total DDTs is 572 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-2/16/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55042
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for DDT.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDT is 62.9 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55050
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for DDT. Data assessed were suspended sediment samples isolated from the whole water sample.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDT is 62.9 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-2/16/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55041
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for DDT(p,p). Eight sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 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 McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55040
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for DDT(p,p). Eight 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 in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The DDT(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 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 McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55039
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for DDT(p,p). Eight sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 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 McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82748, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55049
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for DDT.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDT is 62.9 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
 
DECISION ID
80388
Region 3     
McGowan Ditch
 
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 section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Five lines of evidence are available in the administrative record to assess this pollutant. One of the nine samples exceed the evaluation guideline (Finlayson, 2004) applied to protect for aquatic life beneficial uses. Zero of the nine samples exceed the USEPA drinking water health advisory. Zero out of three sediment samples did not exceed the aquatic life evaluation guideline (Ding et al. 2011). 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 supported using table 3.1.

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

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. One of nine samples exceeded the evaluation guideline (Finlayson, 2004) applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 80388, Diazinon
Region 3     
McGowan Ditch
 
LOE ID: 55059
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Diazinon.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for diazinon is the median lethal concentration (LC50) of 11 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 11 ug/g is the geometric mean of LC50 values for diazinon from Ding et al. (2011).
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 80388, Diazinon
Region 3     
McGowan Ditch
 
LOE ID: 55064
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Diazinon.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for diazinon is the median lethal concentration (LC50) of 11 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 11 ug/g is the geometric mean of LC50 values for diazinon from Ding et al. (2011).
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 80388, Diazinon
Region 3     
McGowan Ditch
 
LOE ID: 55065
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 9 samples exceed the criterion for DIAZINON.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
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 McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 80388, Diazinon
Region 3     
McGowan Ditch
 
LOE ID: 55066
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 9 samples exceed the criterion for DIAZINON.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
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 McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 80388, Diazinon
Region 3     
McGowan Ditch
 
LOE ID: 55067
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for DIAZINON.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA drinking water health advisory for diazinon is 1 µg/L.
Guideline Reference: 2011 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82685
Region 3     
McGowan Ditch
 
Pollutant: Disulfoton
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guideline for drinking water (USEPA drinking water health advisory level, 2011). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82685, Disulfoton
Region 3     
McGowan Ditch
 
LOE ID: 55068
 
Pollutant: Disulfoton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for DISULFOTON.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA drinking water health advisory for disulfoton is 0.7 µg/L.
Guideline Reference: 2011 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
99841
Region 3     
McGowan Ditch
 
Pollutant: Esfenvalerate/Fenvalerate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Four lines of evidence are available in the administrative record to assess this pollutant. Zero of the nine water samples exceed the evaluation guideline (USEPA Office of Pesticide Programs Ecotoxicity database) and zero of the three sediment samples exceed the evaluation guideline (Amweg, E.L., et. Al., 2005 ) used to interpret the narrative water quality objective for aquatic life. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine water samples exceed the evaluation guideline and zero of the three sediment samples exceed the evaluation guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 99841, Esfenvalerate/Fenvalerate
Region 3     
McGowan Ditch
 
LOE ID: 55074
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for ESFENVALERATE.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.13 ug/L, as determined in a 96 hour toxicity test using the fathead minnow, Pimephales promelas (USEPA Office of Pesticide Programs Ecotoxicity database).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 99841, Esfenvalerate/Fenvalerate
Region 3     
McGowan Ditch
 
LOE ID: 55073
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for ESFENVALERATE.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.13 ug/L, as determined in a 96 hour toxicity test using the fathead minnow, Pimephales promelas (USEPA Office of Pesticide Programs Ecotoxicity database).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 99841, Esfenvalerate/Fenvalerate
Region 3     
McGowan Ditch
 
LOE ID: 55076
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Esfenvalerate.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 99841, Esfenvalerate/Fenvalerate
Region 3     
McGowan Ditch
 
LOE ID: 55075
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Esfenvalerate.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
 
DECISION ID
82010
Region 3     
McGowan Ditch
 
Pollutant: Fipronil
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the three sediment samples exceed the evaluation guideline for aquatic life protection (Maul et al. 2008). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the three samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82010, Fipronil
Region 3     
McGowan Ditch
 
LOE ID: 55091
 
Pollutant: Fipronil
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Fipronil.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for fipronil is the median lethal concentration (LC50) of 0.13 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).
Guideline Reference: Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival. Environ. Toxicol. Chem. 27(12):2582-2590.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82010, Fipronil
Region 3     
McGowan Ditch
 
LOE ID: 55090
 
Pollutant: Fipronil
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Fipronil.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for fipronil is the median lethal concentration (LC50) of 0.13 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).
Guideline Reference: Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival. Environ. Toxicol. Chem. 27(12):2582-2590.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
 
DECISION ID
82011
Region 3     
McGowan Ditch
 
Pollutant: Fipronil Sulfide
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the three sediment samples exceed the evaluation guideline for aquatic life protection (Maul et al. 2008). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the three samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82011, Fipronil Sulfide
Region 3     
McGowan Ditch
 
LOE ID: 54969
 
Pollutant: Fipronil Sulfide
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Fipronil sulfide.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for fipronil sulfide is the median lethal concentration (LC50) of 0.16 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).
Guideline Reference: Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival. Environ. Toxicol. Chem. 27(12):2582-2590.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82011, Fipronil Sulfide
Region 3     
McGowan Ditch
 
LOE ID: 54970
 
Pollutant: Fipronil Sulfide
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Fipronil sulfide.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for fipronil sulfide is the median lethal concentration (LC50) of 0.16 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).
Guideline Reference: Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival. Environ. Toxicol. Chem. 27(12):2582-2590.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
 
DECISION ID
82064
Region 3     
McGowan Ditch
 
Pollutant: Fipronil Sulfone
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the three sediment samples exceed the evaluation guideline for aquatic life protection (Maul et al. 2008). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the three samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82064, Fipronil Sulfone
Region 3     
McGowan Ditch
 
LOE ID: 54972
 
Pollutant: Fipronil Sulfone
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Fipronil sulfone.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for fipronil sulfone is the median lethal concentration (LC50) of 0.12 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).
Guideline Reference: Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival. Environ. Toxicol. Chem. 27(12):2582-2590.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82064, Fipronil Sulfone
Region 3     
McGowan Ditch
 
LOE ID: 54971
 
Pollutant: Fipronil Sulfone
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Fipronil sulfone.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for fipronil sulfone is the median lethal concentration (LC50) of 0.12 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).
Guideline Reference: Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival. Environ. Toxicol. Chem. 27(12):2582-2590.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
 
DECISION ID
99797
Region 3     
McGowan Ditch
 
Pollutant: Iprodione
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guideline for drinking water (USEPA IRIS reference dose). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 99797, Iprodione
Region 3     
McGowan Ditch
 
LOE ID: 54980
 
Pollutant: Iprodione
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Iprodione.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for Iprodione is 280 µg/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, and 20% relative source contribution from drinking water with 0.04 mg/kg/day as the reference dose. An additional uncertainty factor of 10 is used for Class C carcinogens.
Guideline Reference: IRIS Summary for Iprodione
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82798
Region 3     
McGowan Ditch
 
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 section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Four lines of evidence are available in the administrative record to assess this pollutant. Zero of the nine water samples exceed the evaluation guideline for aquatic life protection (CDFG, 1992), zero of the nine water samples exceed the evaluation guideline for drinking water (USEPA IRIS reference dose) and zero of the three sediment samples exceed the evaluation guideline (Ding et al., 2011) used to interpret the narrative water quality objective for aquatic life. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine water samples exceed the evaluation guidelines and zero of the three sediment samples exceed the evaluation guideline. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82798, Methyl Parathion
Region 3     
McGowan Ditch
 
LOE ID: 55002
 
Pollutant: Methyl Parathion
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Methyl parathion.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for methyl parathion is the median lethal concentration (LC50) of 6 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 6 ug/g is the geometric mean of LC50 values for methyl parathion from Ding et al. (2011).
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82798, Methyl Parathion
Region 3     
McGowan Ditch
 
LOE ID: 55003
 
Pollutant: Methyl Parathion
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Methyl parathion.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for methyl parathion is the median lethal concentration (LC50) of 6 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 6 ug/g is the geometric mean of LC50 values for methyl parathion from Ding et al. (2011).
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82798, Methyl Parathion
Region 3     
McGowan Ditch
 
LOE ID: 54997
 
Pollutant: Methyl Parathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Parathion, methyl.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Department of Fish and Game (now called the California Department of Fish and Wildlife) instantaneous criteria for Methyl Parathion is 0.08 ug/L.
Guideline Reference: Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82798, Methyl Parathion
Region 3     
McGowan Ditch
 
LOE ID: 54995
 
Pollutant: Methyl Parathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Parathion, methyl.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for phorate is 1.8 µg/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, and 20% relative source contribution from drinking water.  An additional uncertainty factor of 10 is used for Class C carcinogens.
Guideline Reference: IRIS Database Calculations (summary)
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82798, Methyl Parathion
Region 3     
McGowan Ditch
 
LOE ID: 54996
 
Pollutant: Methyl Parathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Parathion, methyl.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Department of Fish and Game (now called the California Department of Fish and Wildlife) instantaneous criteria for Methyl Parathion is 0.08 ug/L.
Guideline Reference: Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82641
Region 3     
McGowan Ditch
 
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 is necessary to assess listing status.

Four lines of evidence are available in the administrative record to assess this pollutant. One of the nine samples exceed the water quality objective for dissolved oxygen in Cold Freshwater Habitats and zero of the nine samples exceeded the water quality objective for dissolved oxygen in Warm Freshwater Habitats. 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 supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using table 3.2. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of the nine samples exceed the water quality objective for dissolved oxygen in Cold Freshwater Habitats and zero of the nine samples exceeded the water quality objective for dissolved oxygen in Warm Freshwater Habitats. These do not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
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 82641, Oxygen, Dissolved
Region 3     
McGowan Ditch
 
LOE ID: 47846
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Region 3 - Central Coast Region staff assessed R3 public submissions data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr]
Temporal Representation: Data was collected over the time period 1/6/2008 11:30:00 AM-10/28/2009 8:55:00 AM.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: A QAPP was not specifically written for this project. However, staff conducting data collection and laboratory analysis are also SWAMP contractors. All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA
 
Line of Evidence (LOE) for Decision ID 82641, Oxygen, Dissolved
Region 3     
McGowan Ditch
 
LOE ID: 17874
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 82641, Oxygen, Dissolved
Region 3     
McGowan Ditch
 
LOE ID: 17875
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 82641, Oxygen, Dissolved
Region 3     
McGowan Ditch
 
LOE ID: 47845
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Region 3 - Central Coast Region staff assessed R3 public submissions data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr]
Temporal Representation: Data was collected over the time period 1/6/2008 11:30:00 AM-10/28/2009 8:55:00 AM.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: A QAPP was not specifically written for this project. However, staff conducting data collection and laboratory analysis are also SWAMP contractors. All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA
 
 
DECISION ID
82736
Region 3     
McGowan Ditch
 
Pollutant: Pentachlorobenzene (PCNB)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guideline for drinking water. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82736, Pentachlorobenzene (PCNB)
Region 3     
McGowan Ditch
 
LOE ID: 55013
 
Pollutant: Pentachlorobenzene (PCNB)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for PCNB.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Department of Health Services archived Advisory Level for Pentachloronitrobenzene is 20 ug/L.
Guideline Reference: IRIS Database Calculations (summary)
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
81998
Region 3     
McGowan Ditch
 
Pollutant: Propanil (DCPA mono- and di-acid degrad)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guideline for aquatic life protection (USEPA maximum acceptable toxicant concentration (MATC)). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 81998, Propanil (DCPA mono- and di-acid degrad)
Region 3     
McGowan Ditch
 
LOE ID: 55037
 
Pollutant: Propanil (DCPA mono- and di-acid degrad)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for PROPANIL.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Propanil is the maximum acceptable toxicant concentration (MATC) of 0.5 ug/L. The MATC (or Chronic Value as defined in USEPA 1985, P20 section F) is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 0.6 ug/L and the no observed effect concentration (NOEC) of 0.4 ug/L, as determined in a 60 day toxicity study with the fathead minnow, Pimephales promelas. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
Guideline Reference: Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 81998, Propanil (DCPA mono- and di-acid degrad)
Region 3     
McGowan Ditch
 
LOE ID: 55036
 
Pollutant: Propanil (DCPA mono- and di-acid degrad)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for PROPANIL.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Propanil is the maximum acceptable toxicant concentration (MATC) of 0.5 ug/L. The MATC (or Chronic Value as defined in USEPA 1985, P20 section F) is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 0.6 ug/L and the no observed effect concentration (NOEC) of 0.4 ug/L, as determined in a 60 day toxicity study with the fathead minnow, Pimephales promelas. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
Guideline Reference: Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
99798
Region 3     
McGowan Ditch
 
Pollutant: Resmethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guideline for drinking water (USEPA IRIS reference dose). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 99798, Resmethrin
Region 3     
McGowan Ditch
 
LOE ID: 55044
 
Pollutant: Resmethrin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for RESMETHRIN.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for Resmethrin is 210 µg/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, and 20% relative source contribution from drinking water.  An additional uncertainty factor of 10 is used for Class C carcinogens.
Guideline Reference: IRIS Database Calculations (summary)
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82697
Region 3     
McGowan Ditch
 
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 is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 11 samples exceed the evaluation guideline (Moyle, 1976) used to interpret the water quality objective for water temperature. 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 supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using table 3.2. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the 11 samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82697, Temperature, water
Region 3     
McGowan Ditch
 
LOE ID: 17418
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Water Temperature.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: Inland Fishes of California
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 82697, Temperature, water
Region 3     
McGowan Ditch
 
LOE ID: 47863
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Region 3 - Central Coast Region staff assessed R3 public submissions data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Water Temperature.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The optimum range for growth and completion of most life stages of rainbow trout is 13-21 degrees Celsius (Moyle 1976).
Guideline Reference: Inland Fishes of California
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr]
Temporal Representation: Data was collected over the time period 1/6/2008 11:30:00 AM-10/28/2009 8:55:00 AM.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: A QAPP was not specifically written for this project. However, staff conducting data collection and laboratory analysis are also SWAMP contractors. All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA
 
 
DECISION ID
82631
Region 3     
McGowan Ditch
 
Pollutant: Thiobencarb/Bolero
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guidelines for aquatic life protection (maximum acceptable toxicant concentration (MATC)) and drinking water (The California Maximum Contaminant Level). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 82631, Thiobencarb/Bolero
Region 3     
McGowan Ditch
 
LOE ID: 55052
 
Pollutant: Thiobencarb/Bolero
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for THIOBENCARB.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for thiobencarb is 0.07 mg/L (Title 22 of the California Code of Regulations).
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82631, Thiobencarb/Bolero
Region 3     
McGowan Ditch
 
LOE ID: 55053
 
Pollutant: Thiobencarb/Bolero
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for THIOBENCARB.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Thiobencarb is the maximum acceptable toxicant concentration (MATC) of 1.4 ug/L. The MATC (or Chronic Value as defined in USEPA 1985, P20 section F) is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 2.0 ug/L and the no observed effect concentration (NOEC) of 1.0 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
Guideline Reference: Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82631, Thiobencarb/Bolero
Region 3     
McGowan Ditch
 
LOE ID: 55054
 
Pollutant: Thiobencarb/Bolero
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for THIOBENCARB.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Thiobencarb is the maximum acceptable toxicant concentration (MATC) of 1.4 ug/L. The MATC (or Chronic Value as defined in USEPA 1985, P20 section F) is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 2.0 ug/L and the no observed effect concentration (NOEC) of 1.0 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
Guideline Reference: Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82738
Region 3     
McGowan Ditch
 
Pollutant: Vinclozolin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guideline for drinking water (USEPA IRIS reference dose). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the nine samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82738, Vinclozolin
Region 3     
McGowan Ditch
 
LOE ID: 55072
 
Pollutant: Vinclozolin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Vinclozolin.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for Vinclozolin is 180 µg/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, and 20% relative source contribution from drinking water.  An additional uncertainty factor of 10 is used for Class C carcinogens.
Guideline Reference: IRIS Database Calculations (summary)
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82696
Region 3     
McGowan Ditch
 
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 is necessary to assess listing status.

Ten lines of evidence are available in the administrative record to assess this pollutant. Five beneficial uses are assessed. Three of the 11 samples exceed the water quality objectives for Cold and Warm Freshwater Habitats, and two of the 11 samples exceed the water quality objectives for Drinking Water and Recreation. 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 supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using table 3.2. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Three of the 11 samples exceed the water quality objectives for Cold and Warm Freshwater Habitats, and two of the 11 samples exceed the water quality objectives for Drinking Water and Recreation. These do not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
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 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 47861
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 9
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Region 3 - Central Coast Region staff assessed R3 public submissions data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 9 samples exceed the criterion for pH.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr]
Temporal Representation: Data was collected over the time period 1/6/2008 11:30:00 AM-10/28/2009 8:55:00 AM.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: A QAPP was not specifically written for this project. However, staff conducting data collection and laboratory analysis are also SWAMP contractors. All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA
 
Line of Evidence (LOE) for Decision ID 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 17392
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 17393
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 47862
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Region 3 - Central Coast Region staff assessed R3 public submissions data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 9 samples exceed the criterion for pH.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH value shall not be depressed below 7.0 or raised above 8.5 (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr]
Temporal Representation: Data was collected over the time period 1/6/2008 11:30:00 AM-10/28/2009 8:55:00 AM.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: A QAPP was not specifically written for this project. However, staff conducting data collection and laboratory analysis are also SWAMP contractors. All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA
 
Line of Evidence (LOE) for Decision ID 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 47860
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 9
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Region 3 - Central Coast Region staff assessed R3 public submissions data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 9 samples exceed the criterion for pH.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr]
Temporal Representation: Data was collected over the time period 1/6/2008 11:30:00 AM-10/28/2009 8:55:00 AM.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: A QAPP was not specifically written for this project. However, staff conducting data collection and laboratory analysis are also SWAMP contractors. All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA
 
Line of Evidence (LOE) for Decision ID 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 17391
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 47859
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Region 3 - Central Coast Region staff assessed R3 public submissions data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 9 samples exceed the criterion for pH.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH value shall not be depressed below 6.5 or raised above 8.3 (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr]
Temporal Representation: Data was collected over the time period 1/6/2008 11:30:00 AM-10/28/2009 8:55:00 AM.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: A QAPP was not specifically written for this project. However, staff conducting data collection and laboratory analysis are also SWAMP contractors. All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA
 
Line of Evidence (LOE) for Decision ID 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 17672
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Municipal and Domestic Supply Objectives, Section II.A.2.a states the following: The pH value shall neither be depressed below 6.5 or raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 47858
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Region 3 - Central Coast Region staff assessed R3 public submissions data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 9 samples exceed the criterion for pH.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH value shall not be depressed below 7.0 or raised above 8.5 (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr]
Temporal Representation: Data was collected over the time period 1/6/2008 11:30:00 AM-10/28/2009 8:55:00 AM.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: A QAPP was not specifically written for this project. However, staff conducting data collection and laboratory analysis are also SWAMP contractors. All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA
 
Line of Evidence (LOE) for Decision ID 82696, pH
Region 3     
McGowan Ditch
 
LOE ID: 17671
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
 
DECISION ID
82701
Region 3     
McGowan Ditch
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.

Six lines of evidence are available in the administrative record to assess this pollutant. Three of the three water samples exceed the evaluation guideline (California Toxics Rule, 2000). In addition, three of the six sediment samples exceed the evaluation guideline (MacDonald et al. 2000) used to interpret the narrative water quality objective for aquatic life. Three of the sediment samples were tested for toxic effects to invertebrate test organisms and two of the three samples did result in a significant toxic effect. This water segment is also on the 303(d) List for toxicity in sediment.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Three of the three water samples exceed the evaluation guideline (California Toxics Rule, 2000), three of the six sediment samples exceed the evaluation guideline (MacDonald et al. 2000) used to interpret the narrative water quality objective for aquatic life and two of the three samples did result in a significant toxic effect. This exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 82701, DDD (Dichlorodiphenyldichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55017
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for DDD.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDD is 28.0 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82701, DDD (Dichlorodiphenyldichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55069
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Three samples were collected to evaluate sediment toxicity. Two of the three samples exhibited significant toxicity. The toxicity tests included survival and growth of Hyalella azteca. Statistically significant effects on Hyalella azteca were observed in samples collected on 7/2/2008, and 10/28/2009.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 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 (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Toxicity was 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: Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064
 
Spatial Representation: The samples were collected at McGowan Ditch station 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowan Rd and Bluff Dr.
Temporal Representation: The samples were collected in July and October 2008 and October 2009.
Environmental Conditions:
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82701, DDD (Dichlorodiphenyldichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55022
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for DDD. Data assessed were suspended sediment samples isolated from the whole water sample.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDD is 28.0 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-2/16/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82701, DDD (Dichlorodiphenyldichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55024
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for DDD. Data assessed were suspended sediment samples isolated from the whole water sample.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDD is 28.0 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-2/16/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82701, DDD (Dichlorodiphenyldichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55023
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for DDD.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDD is 28.0 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82701, DDD (Dichlorodiphenyldichloroethane)
Region 3     
McGowan Ditch
 
LOE ID: 55016
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 3
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 3 of 3 samples exceed the criterion for DDD(p,p). Six 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 in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The DDD(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00083 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 McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
82747
Region 3     
McGowan Ditch
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 of the Listing Policy, a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list.
Six lines of evidence are available in the administrative record to assess this pollutant. Nine of the nine water samples exceed the evaluation guideline (California Toxics Rule, 2000). In addition, four of the six sediment samples exceed the evaluation guideline (MacDonald et al. 2000) used to interpret the narrative water quality objective for aquatic life. Three of the sediment samples were tested for toxic effects to invertebrate test organisms and two of the three samples did result in a significant toxic effect. This water segment is also on the 303(d) List for toxicity in sediment.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Nine of the nine water samples exceed the evaluation guideline (California Toxics Rule, 2000), four of the six sediment samples exceed the evaluation guideline (MacDonald et al. 2000) used to interpret the narrative water quality objective for aquatic life and two of the three samples did result in a significant toxic effect. This exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 82747, DDE (Dichlorodiphenyldichloroethylene)
Region 3     
McGowan Ditch
 
LOE ID: 55031
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for DDE.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDE is 31.3 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82747, DDE (Dichlorodiphenyldichloroethylene)
Region 3     
McGowan Ditch
 
LOE ID: 55069
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Three samples were collected to evaluate sediment toxicity. Two of the three samples exhibited significant toxicity. The toxicity tests included survival and growth of Hyalella azteca. Statistically significant effects on Hyalella azteca were observed in samples collected on 7/2/2008, and 10/28/2009.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 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 (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Toxicity was 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: Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064
 
Spatial Representation: The samples were collected at McGowan Ditch station 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowan Rd and Bluff Dr.
Temporal Representation: The samples were collected in July and October 2008 and October 2009.
Environmental Conditions:
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 82747, DDE (Dichlorodiphenyldichloroethylene)
Region 3     
McGowan Ditch
 
LOE ID: 55032
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for DDE. Data assessed were suspended sediment samples isolated from the whole water sample.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDE is 31.3 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-2/16/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82747, DDE (Dichlorodiphenyldichloroethylene)
Region 3     
McGowan Ditch
 
LOE ID: 55034
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for DDE. Data assessed were suspended sediment samples isolated from the whole water sample.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDE is 31.3 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-2/16/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82747, DDE (Dichlorodiphenyldichloroethylene)
Region 3     
McGowan Ditch
 
LOE ID: 55033
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for DDE.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDE is 31.3 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 7/2/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
QAPP Information Reference(s): Quality Assurance Project Plan from UC Davis Marine Pollution Studies Laboratory.
 
Line of Evidence (LOE) for Decision ID 82747, DDE (Dichlorodiphenyldichloroethylene)
Region 3     
McGowan Ditch
 
LOE ID: 55025
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 9
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 9 of 9 samples exceed the criterion for DDE(p,p). Zero 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 in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The DDE(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 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 McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
99796
Region 3     
McGowan Ditch
 
Pollutant: Malathion
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the nine samples exceed the evaluation guideline for drinking water (USEPA drinking water health advisory) but two of the two samples exceed the evaluation guideline for aquatic life uses (Fojut, T.L., et al., 2012). Note, seven of the nine samples are not included in the LOEs for Cold and Warm freshwater habitats because the results were ¿non-detect¿ but the laboratory reporting limit was above the evaluation guideline. Therefore staff are unable to determine if the guideline was exceeded. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Two of the two samples exceed the evaluation guideline for aquatic life uses and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 99796, Malathion
Region 3     
McGowan Ditch
 
LOE ID: 54986
 
Pollutant: Malathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 9 samples exceed the criterion for MALATHION. Seven sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
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 McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 99796, Malathion
Region 3     
McGowan Ditch
 
LOE ID: 54987
 
Pollutant: Malathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 9 samples exceed the criterion for MALATHION. Seven sample results were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
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 McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 99796, Malathion
Region 3     
McGowan Ditch
 
LOE ID: 54981
 
Pollutant: Malathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 9
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed USGS data for McGowan Ditch to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for MALATHION.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Central Coast Basin Plan General Objective).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA drinking water health advisory for malathion is 500 µg/L.
Guideline Reference: 2011 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 1 monitoring site [ Monterey Drainage Ditch - trib to Pajaro River between McGowean Rd and Bluff Dr - 305MDD]
Temporal Representation: Data was collected over the time period 1/6/2008-10/28/2009.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
 
DECISION ID
80638
Region 3     
McGowan Ditch
 
Pollutant: Nitrate
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2018
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: No new data are assessed.

This pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.1 of the Listing Policy.

One line of evidence is available in the administrative record to assess this pollutant. Based on section 3.1 the site exceeded numeric objectives for toxic pollutants. Using the binomial distribution, waters shall be placed on the section 303(d) list if the number of measured exceedances supports rejection of the null hypothesis as presented in Table 3.1.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Both of the 2 samples exceeded the water quality objective for Municipal and Domestic Supply and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 80638, Nitrate
Region 3     
McGowan Ditch
 
LOE ID: 17727
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for McGowan Ditch to determine beneficial use support and results are as follows: 2 of 2 samples exceed the criterion for Nitrate as N.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin Objective for municipal and domestic supply uses of inland surface waters (Section II.A.2) states the following: waters shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Article 4, Chapter 15, Section 64435, Tables 2 and 3 as listed in Table 3-2. The maximum contaminant level listed in Table 3-2 (inorganic and fluoride concentrations not to be exceeded in domestic or municipal supply) for nitrate is 10.0 mg/L (NO3 as N).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
Objective/Criterion Reference: Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for McGowan Ditch was collected at 2 monitoring sites [ MG-MCI MG-TRA - McGowan Ditch at Trafton]
Temporal Representation: Data was collected over the time period 2/7/2006-11/14/2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
 
DECISION ID
91612
Region 3     
McGowan Ditch
 
Pollutant: Toxicity
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2023
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day and time at the same location.

Two LOEs summarize water samples. Two water samples are summarized in LOEs using each of the test organisms as the pollutant name (i.e. plant toxicity, invertebrate toxicity or vertebrate toxicity) and zero additional water samples are summarized in LOEs using the pollutant name ¿toxicity¿. Therefore, two total samples are available to assess toxic effects in water samples. Zero of the two water samples resulted in a significant toxic effect to one or more test organisms.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Two of the 3 sediment samples and 2 of the 9 water samples exceed the water quality objective for aquatic life protection and these exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 91612, Toxicity
Region 3     
McGowan Ditch
 
LOE ID: 79214
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Nine samples were collected to evaluate water toxicity. Two of the nine sample exhibited significant toxicity. The toxicity tests included survival of Hyalella azteca and survival of Ceriodaphnia dubia. Statistically significant effects to both Hyalella azteca and Ceriodaphnia dubia were observed in one sample, collected on 10/14/2009 and significant effects to Ceriodaphnia dubia were observed in the sample collected on 2/16/2009.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 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 (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Toxicity was 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: Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012
 
Spatial Representation: The samples were collected at station 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowan Rd and Bluff Dr.
Temporal Representation: The samples were collected between January 2008 and October 2009.
Environmental Conditions:
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 91612, Toxicity
Region 3     
McGowan Ditch
 
LOE ID: 55069
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Three samples were collected to evaluate sediment toxicity. Two of the three samples exhibited significant toxicity. The toxicity tests included survival and growth of Hyalella azteca. Statistically significant effects on Hyalella azteca were observed in samples collected on 7/2/2008, and 10/28/2009.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 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 (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Toxicity was 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: Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064
 
Spatial Representation: The samples were collected at McGowan Ditch station 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowan Rd and Bluff Dr.
Temporal Representation: The samples were collected in July and October 2008 and October 2009.
Environmental Conditions:
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 91612, Toxicity
Region 3     
McGowan Ditch
 
LOE ID: 79215
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Three samples were collected to evaluate sediment toxicity. Two of the three samples exhibited significant toxicity. The toxicity tests included survival and growth of Hyalella azteca. Statistically significant effects on Hyalella azteca were observed in samples collected on 7/2/2008, and 10/28/2009.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 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 (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Toxicity was 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: Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012
 
Spatial Representation: The samples were collected at McGowan Ditch station 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowan Rd and Bluff Dr.
Temporal Representation: The samples were collected in July and October 2008 and October 2009.
Environmental Conditions:
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 91612, Toxicity
Region 3     
McGowan Ditch
 
LOE ID: 55063
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Nine samples were collected to evaluate water toxicity. Two of the nine sample exhibited significant toxicity. The toxicity tests included survival of Hyalella azteca and survival of Ceriodaphnia dubia. Statistically significant effects to both Hyalella azteca and Ceriodaphnia dubia were observed in one sample, collected on 10/14/2009 and significant effects to Ceriodaphnia dubia were observed in the sample collected on 2/16/2009.
Data Reference: Data for various pollutants in the Pajaro, Salinas, and Santa Maria River estuaries, Jan. 2008-Oct. 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 (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Toxicity was 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: Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012
 
Spatial Representation: The samples were collected at station 305MDD - Monterey Drainage Ditch - trib to Pajaro River between McGowan Rd and Bluff Dr.
Temporal Representation: The samples were collected between January 2008 and October 2009.
Environmental Conditions:
QAPP Information: The data was collected for the Watershed-scale Evaluation of Agricultural BMP Effectiveness Protecting Critical Coastal Habitats project. A QAPP was provided and the data was analyzed at the Marine Pollution Studies Laboratory and submitted in SWAMP format.
QAPP Information Reference(s):