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

# Supporting Information

## Regional Board 3 - Central Coast Region

Water Body Name: | Arroyo Grande Creek (below Lopez Lake)
Water Body ID: | CAR3103101419980804113947
Water Body Type: | River & Stream

DECISION ID | 10595
Pollutant: | Ammonia (Unionized)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. One of 113 samples exceed both the Warm and Cold Freshwater Habitat objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of 113 samples exceed the both Warm and Cold Freshwater Habitat objectives and in neither case does this exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10595

LOE ID: | 14731
Pollutant: | Ammonia (Unionized)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9885
Pollutant: | Ammonia (Unionized)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 56
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 56 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10108
Pollutant: | Ammonia (Unionized)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10107
Pollutant: | Ammonia (Unionized)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14732
Pollutant: | Ammonia (Unionized)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9886
Pollutant: | Ammonia (Unionized)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 56
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 56 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15464
Pollutant: | Anthracene
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15464

LOE ID: | 15715
Pollutant: | Anthracene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Anthracene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for anthracene is 845 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15716
Pollutant: | Anthracene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Anthracene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for anthracene is 845 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10598
Pollutant: | Arsenic
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. There are also an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The sample did not exceed the Evaluation Guideline, but the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are met or exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10598

LOE ID: | 15804
Pollutant: | Arsenic
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Arsenic.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for arsenic is 33 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15790
Pollutant: | Arsenic
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Arsenic.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for arsenic is 33 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15466
Pollutant: | Benzo(a)pyrene (3,4-Benzopyrene -7-d)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15466

LOE ID: | 15483
Pollutant: | Benzo(a)pyrene (3,4-Benzopyrene -7-d)
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Benzo(a)pyrene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Benzo(a)Pyrene is 1450 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15470
Pollutant: | Benzo(a)pyrene (3,4-Benzopyrene -7-d)
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Benzo(a)pyrene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Benzo(a)Pyrene is 1450 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15467
Pollutant: | Benzo[a]anthracene
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15467

LOE ID: | 15599
Pollutant: | Benzo[a]anthracene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Benzo(a)anthracene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Benzo(a)anthracene is 1050 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15600
Pollutant: | Benzo[a]anthracene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Benzo(a)anthracene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Benzo(a)anthracene is 1050 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10602
Pollutant: | Boron
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the 74 samples exceed the Agricultural Supply objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 74 samples exceed the Agricultural Supply objective and therefore this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10602

LOE ID: | 9869
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Agricultural Supply
Number of Samples: | 24
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 24 samples exceed the criterion for Boron, dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in Table 3.4 (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). Table 3-4 (page III-9) lists the maximum concentration for boron for irrigation supply is 0.75 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-7/29/2002. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9887
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Agricultural Supply
Number of Samples: | 50
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 50 samples exceed the criterion for Boron, dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in Table 3.4 (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). Table 3-4 (page III-9) lists the maximum concentration for boron for irrigation supply is 0.75 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10599
Pollutant: | Cadmium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence from a single sample are available in the administrative record to assess this pollutant. The sample exceeded the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. There are also an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample exceeded the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective, but did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The single sample exceeded the Evaluation Guideline, but the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are met or exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10599

LOE ID: | 15584
Pollutant: | Cadmium
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life 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: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Cadmium.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for cadmium is 4.98 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15583
Pollutant: | Cadmium
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life 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: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Cadmium.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for cadmium is 4.98 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15477
Pollutant: | Chlorophyll-a
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant. None of the 113 samples exceed the Evaluation Guideline (North Carolina Administrative code, Title 15A) and the General Water Quality Objective set to protect aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 113 samples exceed the Evaluation Guideline (North Carolina Administrative code, Title 15A) and the General Water Quality Objective set to protect aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15477

LOE ID: | 14746
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14747
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12547
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 7/3/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12548
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 7/3/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12726
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12727
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9888
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 55
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 55 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9900
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 55
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 55 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15478
Pollutant: | Chlorpyrifos
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample exceeds the Evaluation Guideline (Sipmann and Finlayson, 2000) applied to protect for aquatic life beneficial uses. 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. The single sample exceeds the Evaluation Guideline (Sipmann and Finlayson, 2000) applied to protect for aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15478

LOE ID: | 15650
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life 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: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Chlorpyrifos.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
| Final Data File used for assessment: SWAMP Sediment Chemistry Data from Region 3 Harbors, 2004
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion 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
| Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | One hour average maximum concentration 0.025 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15649
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life 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: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Chlorpyrifos.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
| Final Data File used for assessment: SWAMP Sediment Chemistry Data from Region 3 Harbors, 2004
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion 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
| Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | One hour average maximum concentration 0.025 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10600
Pollutant: | Chromium (total)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. There are also an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The single sample did not exceed the Evaluation Guideline, and the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are met or exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10600

LOE ID: | 16025
Pollutant: | Chromium (total)
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chromium.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for chromium is 111 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 16026
Pollutant: | Chromium (total)
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chromium.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for chromium is 111 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15468
Pollutant: | Chrysene (C1-C4)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15468

LOE ID: | 15858
Pollutant: | Chrysene (C1-C4)
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chrysene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Chrysene is 1290 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15859
Pollutant: | Chrysene (C1-C4)
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chrysene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Chrysene is 1290 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10609
Pollutant: | Copper
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. There are also an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective, and therefore did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are met or exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10609

LOE ID: | 15956
Pollutant: | Copper
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Copper.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for cooper is 149 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15943
Pollutant: | Copper
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Copper.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for cooper is 149 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15479
Pollutant: | Diazinon
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample does not exceed the Evaluation Guideline (Sipmann and Finlayson, 2000) applied to protect for aquatic life beneficial uses. 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. The single sample does not exceed the Evaluation Guideline (Sipmann and Finlayson, 2000) applied to protect for aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15479

LOE ID: | 16822
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion 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
| Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | One hour average maximum concentration 0.16 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 16836
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion 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
| Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | One hour average maximum concentration 0.16 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15469
Pollutant: | Dieldrin
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15469

LOE ID: | 16647
Pollutant: | Dieldrin
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Dieldrin.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for dieldrin is 61.8 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 16648
Pollutant: | Dieldrin
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Dieldrin.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for dieldrin is 61.8 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15470
Pollutant: | Endrin
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15470

LOE ID: | 16467
Pollutant: | Endrin
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endrin.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for endrin is 207 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 16468
Pollutant: | Endrin
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endrin.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for endrin is 207 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15471
Pollutant: | Fluoranthene
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15471

LOE ID: | 16552
Pollutant: | Fluoranthene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fluoranthene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Fluoranthene is 2,230 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 16565
Pollutant: | Fluoranthene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fluoranthene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Fluoranthene is 2,230 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15472
Pollutant: | Fluorene
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15472

LOE ID: | 16521
Pollutant: | Fluorene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fluorene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for fluorene is 536 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 16522
Pollutant: | Fluorene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fluorene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for fluorene is 536 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10604
Pollutant: | Lead
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. There are also an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded and sample size is insufficient.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10604

LOE ID: | 17264
Pollutant: | Lead
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Lead.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for lead is 128 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 17265
Pollutant: | Lead
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Lead.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for lead is 128 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10606
Pollutant: | Low Dissolved Oxygen
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Sixteen lines of evidence are available in the administrative record to assess this pollutant. Fourteen of 127 samples exceed the Cold Freshwater Habitat objective and 6 of 127 exceed the Warm Freshwater Habitat objective. Thirty-four of 126 samples exceed the general water quality objective for oxygen saturation (applied as a single sample maximum), used to evaluate Cold and Warm Freshwater Habitat. However, the Basin Plan objective states that the median shall not fall below 85% saturation and the median value did not exceed this criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the 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. Fourteen of 127 samples exceed the Cold Freshwater Habitat and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10606

LOE ID: | 12581
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 12
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 12 of 45 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14748
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: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12493
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: | 13
Number of Exceedances: | 7
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 7 of 13 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 4 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park, 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12494
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: | 13
Number of Exceedances: | 5
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 5 of 13 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 4 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park, 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12728
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: | 45
Number of Exceedances: | 4
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 4 of 45 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12495
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 13
Number of Exceedances: | 9
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 9 of 13 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 4 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park, 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12729
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: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14494
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 11
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 11 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14493
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 11
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 11 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12580
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 12
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 12 of 45 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12496
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 13
Number of Exceedances: | 9
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 9 of 13 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 4 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park, 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12515
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 57
Number of Exceedances: | 13
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 13 of 57 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14749
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: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12514
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 57
Number of Exceedances: | 13
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 13 of 57 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12512
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: | 57
Number of Exceedances: | 3
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 3 of 57 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12513
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: | 57
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 57 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10603
Pollutant: | Mercury
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. There are also an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective, but the sample size was insufficient to determine if the water body was impaired using the power and confidence of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The single sample exceeded the Evaluation Guideline, but the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are met or exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10603

LOE ID: | 17347
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Mercury.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for mercury is 1.06 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 17346
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Mercury.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for mercury is 1.06 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15473
Pollutant: | Naphthalene
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15473

LOE ID: | 17163
Pollutant: | Naphthalene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Naphthalene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for naphthalene is 561 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 17164
Pollutant: | Naphthalene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Naphthalene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for naphthalene is 561 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10601
Pollutant: | Nickel
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample exceeded the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. There are also an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 two samples did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. the single sample exceeded the Evaluation Guideline, but the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are met or exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10601

LOE ID: | 16984
Pollutant: | Nickel
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life 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: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Nickel.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for nickel is 48.6 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 16985
Pollutant: | Nickel
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life 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: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Nickel.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for nickel is 48.6 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10616
Pollutant: | Nitrate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. None of the 102 samples exceed the water quality objectives for either Agricultural Supply or Municipal and Domestic Supply. In addition, none of the 12 samples exceed the OEHHA Public Health Goals in support of the Municipal and Domestic Supply objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 102 samples exceed the water quality objectives for either Agricultural Supply or Municipal and Domestic Supply. In addition, none of the 12 samples exceed the OEHHA Public Health Goals in support of the Municipal and Domestic Supply objective. Neither of 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.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10616

LOE ID: | 9565
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 57
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 57 samples exceed the criterion for Nitrate as N.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: | Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
| Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9870
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Nitrate as N.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when nitrate exceeds 30 mg/L NO3 as N in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15278
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Nitrate/Nitrite as N.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion: | OEHHA public Health Goals for Nitrate and Nitrogen in Drinking Water (December 1997). Page 6.
Objective/Criterion Reference: | Public health goals for nitrate and nitrite in drinking water
Evaluation Guideline: | OEHHA Public Health Goal states that sum of the concentration of nitrate + nitrite shall not exceed 10 mg/L (NO3+NO2 expressed as N).
Guideline Reference: | Public health goals for nitrate and nitrite in drinking water
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9871
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Nitrate as N.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: | Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
| Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9564
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 57
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 57 samples exceed the criterion for Nitrate as N.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when nitrate exceeds 30 mg/L NO3 as N in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10596
Pollutant: | Nitrogen, ammonia (Total Ammonia)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the 114 samples exceed the Municipal and Domestic Supply objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 114 samples exceed the Municipal and Domestic Supply objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10596

LOE ID: | 15265
Pollutant: | Ammonia as Nitrogen
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Ammonia As N, Total.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9872
Pollutant: | Ammonia as Nitrogen
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 57
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 57 samples exceed the criterion for Ammonia as N, Total.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10106
Pollutant: | Ammonia as Nitrogen
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Ammonia as N, Total.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15474
Pollutant: | Phenanthrene
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15474

LOE ID: | 17083
Pollutant: | Phenanthrene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Phenanthrene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Phenanthrene is 1170 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 17084
Pollutant: | Phenanthrene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Phenanthrene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Phenanthrene is 1170 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15475
Pollutant: | Pyrene
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life objectives. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15475

LOE ID: | 16978
Pollutant: | Pyrene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Pyrene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Pyrene is 1520 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 16965
Pollutant: | Pyrene
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Pyrene.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for Pyrene is 1520 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10619
Pollutant: | Salinity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the 117 samples exceed the Agricultural Supply water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 117 samples exceed the Agricultural Supply water quality objectiveand this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10619

LOE ID: | 12743
Pollutant: | Salinity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Salinity.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when salinity exceeds 3.0 ppt in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12529
Pollutant: | Salinity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 57
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 57 samples exceed the criterion for Salinity.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when salinity exceeds 3.0 ppt in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14511
Pollutant: | Salinity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Salinity.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when salinity exceeds 3.0 ppt in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12549
Pollutant: | Salinity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Salinity.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when salinity exceeds 3.0 ppt in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/30/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 16078
Pollutant: | Sediment Toxicity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under section 3.6 a single line of evidence is necessary to assess listing status for toxicity. Four lines of evidence are available in the administrative record to assess this pollutant in sediment samples. One of the 2 samples were toxic to invertebrate test organisms (exhibit a significant increase in mortality compared to the laboratory control) and therefore do not exceed the narrative General Objective for toxicity, set to protect for aquatic life beneficial uses. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 2 samples were toxic to invertebrate test organisms. Therefore, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 16078

LOE ID: | 23573
Pollutant: | Invertebrate Toxicity
LOE Subgroup: | Toxicity
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street].
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 23574
Pollutant: | Invertebrate Toxicity
LOE Subgroup: | Toxicity
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street].
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 23572
Pollutant: | Invertebrate Toxicity
LOE Subgroup: | Toxicity
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected on a single day 5/16/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 23571
Pollutant: | Invertebrate Toxicity
LOE Subgroup: | Toxicity
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected on a single day 5/16/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10620
Pollutant: | Temperature, water
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollution
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence is available in the administrative record to assess this pollutant. None of the 127 samples exceed the water quality objective for Cold Freshwater Habitat. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 127 samples exceed the water quality objective for Cold Freshwater Habitat and therefore this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10620

LOE ID: | 12532
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: | 57
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 57 samples exceed the criterion for Water Temperature.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
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 Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14528
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: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Water Temperature.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 Central Coast Region (R3) Basin Plan
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 Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12511
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: | 13
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for Water Temperature.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
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 Arroyo Grande Creek(below res) was collected at 4 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park, 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12746
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: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Water Temperature.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
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 Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 15480
Pollutant: | Turbidity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant. Eight of the 109 samples exceed the Evaluation Guideline (Sigler et al., 1984) applied to protect for aquatic life beneficial uses. 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. Eight of the 109 samples exceed the Evaluation Guideline (Sigler et al., 1984) applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15480

LOE ID: | 14512
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 11
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 11 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. 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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12531
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 50
Number of Exceedances: | 6
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 6 of 50 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. 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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14527
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 11
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 11 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. 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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12530
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 50
Number of Exceedances: | 6
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 6 of 50 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. 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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12745
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 45 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. 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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12744
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 45 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. 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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12550
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life 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: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. 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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/30/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12565
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life 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: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. 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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/30/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 16079
Pollutant: | Unknown Toxicity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 and section 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant in water samples. None of the samples were toxic to test organisms (exhibited a significant increase in mortality or decrease in cell density compared to the laboratory control) and therefore do not exceed the narrative General Objective for toxicity, set to protect for aquatic life beneficial uses. The following is a summary of the results from individual toxicity tests. None of the 3 samples (tested for toxicity to plants) exhibited significant reduction in cell density relative to the control. In addition, none of the 3 samples (tested for toxicity to vertebrate test organisms) exhibited a significant increase in mortality compared to the laboratory control. Lastly, none of the 3 samples, tested for toxicity to invertebrate test organisms exhibited a significant increase in mortality compared to the laboratory control. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples were toxic to test organisms. Therefore, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 16079

LOE ID: | 23566
Pollutant: | Invertebrate Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 2/23/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 23559
Pollutant: | Plant Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Selenastrum capricornutum Growth (Cell Density) 4 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction in cell count of test organism relative to the control (alpha < 0.05) and cell count <80% of control.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 2/23/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 23578
Pollutant: | Vertebrate Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 2/23/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 23558
Pollutant: | Plant Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Selenastrum capricornutum Growth (Cell Density) 4 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction in cell count of test organism relative to the control (alpha < 0.05) and cell count <80% of control.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 2/23/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 23577
Pollutant: | Vertebrate Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 2/23/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 23565
Pollutant: | Invertebrate Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 2/23/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10624
Pollutant: | Zinc
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. There are also an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 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 sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective, and did 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. 3. The single sample exceeded the Evaluation Guideline (MacDonald et al. 2000) as it applies to the General Objective, but the sample size was insufficient to determine if the water body was impaired using the power and confidence of the Listing Policy.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The single sample did not exceed the Evaluation Guideline, but the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are met or exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10624

LOE ID: | 17850
Pollutant: | Zinc
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Zinc.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for zinc is 459 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 17864
Pollutant: | Zinc
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Zinc.
Data Reference: | Final Data File used for assessment: SWAMP Toxicity Data 2001-06
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: | In fresh water sediments the probable effects level (predictive of sediment toxicity) for zinc is 459 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference: | Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10607
Pollutant: | pH
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Twenty-four lines of evidence are available in the administrative record to assess this pollutant. Six of 122 samples exceed the Warm and Cold Freshwater Habitat objectives, 9 of 122 samples exceed the Agricultural Supply objectives, and 18 of 122 samples exceed the Municipal & Domestic Supply, Non-contact Recreation and Water Contact Recreation objectives 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. Six of 122 samples exceed the Warm and Cold Freshwater Habitat objectives, 9 of 122 samples exceed the Agricultural Supply objectives, and 18 of 122 samples exceed the Municipal & Domestic Supply, Non-contact Recreation and Water Contact Recreation objectives. None of these exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10607

LOE ID: | 10949
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10968
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 58
Number of Exceedances: | 7
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 7 of 58 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10766
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10767
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10768
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10729
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 58
Number of Exceedances: | 5
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 5 of 58 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10730
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 58
Number of Exceedances: | 13
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 13 of 58 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10731
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 58
Number of Exceedances: | 13
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 13 of 58 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10732
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 58
Number of Exceedances: | 13
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 13 of 58 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10747
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 58
Number of Exceedances: | 5
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 5 of 58 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14711
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 12
Number of Exceedances: | 4
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 4 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14710
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 12
Number of Exceedances: | 4
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 4 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14495
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 12
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14496
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14509
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 4
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 4 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14510
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
| Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310USG - Arroyo Grande Creek at old USGS Gauge]
Temporal Representation: | Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10951
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10950
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10751
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10750
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10749
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10952
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10933
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10948
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10610
Pollutant: | Escherichia coli (E. Coli)
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Agriculture | Grazing-Related Sources | Urban Runoff/Storm Sewers
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.2 of the Listing Policy. Two lines of evidence are available in the administrative record to assess this pollutant. Based on section 3.2 the site exceeded numeric objectives for conventional pollutants. According to 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 3.2. Eleven out of 25 samples exceeded the Water Contact Recreation objective and support rejectioon of the null hypothesis. None of the 25 samples exceeded the Non-contact Recreation objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eleven out of 25 samples exceeded the Water Contact Recreation objective and this meets or exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10610

LOE ID: | 10770
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 25
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 25 samples exceed the criterion for Escherichia coli.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml. E. coli is a fecal coliform.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 1/10/2005-11/15/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10769
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 25
Number of Exceedances: | 11
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 11 of 25 samples exceed the criterion for Escherichia coli.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Evaluation Guideline: | Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL (as stated in Table 4, page 15)
Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 1/10/2005-11/15/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10613
Pollutant: | Fecal Coliform
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Agriculture | Grazing-Related Sources | Urban Runoff/Storm Sewers
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.2 of the Listing Policy. Four lines of evidence are available in the administrative record to assess this pollutant. Based on section 3.2 the site exceeded numeric objectives for conventional pollutants. According to 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 3.2. Forty-two out of 104 samples exceed the Water Body Contact Recreation objective and support rejection of the null hypothesis. One of 104 samples exceed the Non-contact Recreation objective and do not support rejection of the null hypothesis. 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. Forty-two out of 104 samples exceed the Water Body Contact Recreation objective and this meets or exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10613

LOE ID: | 10931
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Coliform, Fecal.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10930
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 45
Number of Exceedances: | 14
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 14 of 45 samples exceed the criterion for Coliform, Fecal.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 200 MPN/100 ml, nor shall more than ten percent of total samples during any 30-day period exceed 400 MPN/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 11005
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 59
Number of Exceedances: | 28
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 28 of 59 samples exceed the criterion for Coliform, Fecal.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 200 MPN/100 ml, nor shall more than ten percent of total samples during any 30-day period exceed 400 MPN/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-11/15/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 11006
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 59
Number of Exceedances: | 1
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 1 of 59 samples exceed the criterion for Coliform, Fecal.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-11/15/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 10605
Pollutant: | Electrical Conductivity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the 109 samples exceed the Agricultural Supply water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 109 samples exceed the Agricultural Supply water quality objective and therefore this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10605

LOE ID: | 10748
Pollutant: | Electrical Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 7
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Conductivity(Us).
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10932
Pollutant: | Electrical Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 45
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 45 samples exceed the criterion for Conductivity(Us).
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 3 monitoring sites [ 310AGB-Arroyo Grande Creek at Biddle Park, 310AGF-Arroyo Grande Creek at Fair Oaks, 310AGS-Arroyo Grande Creek at Strother Park]
Temporal Representation: | Data was collected over the time period 1/15/2002-3/19/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 10967
Pollutant: | Electrical Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Agricultural Supply
Number of Samples: | 57
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Arroyo Grande Creek(below res) to determine beneficial use support and results are as follows: 0 of 57 samples exceed the criterion for Conductivity(Us).
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Arroyo Grande Creek(below res) was collected at 1 monitoring site [ 310ARG-Arroyo Grande Creek at 22nd Street]
Temporal Representation: | Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):