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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name: Malpaso Creek
Water Body ID: CAR3080001320080605154616
Water Body Type: River & Stream
 
DECISION ID
112623
Region 3     
Malpaso Creek
 
Pollutant: Acenaphthene
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112623, Acenaphthene
Region 3     
Malpaso Creek
 
LOE ID: 157107
 
Pollutant: Acenaphthene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Acenaphthene.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Acenaphthene criteria for the protection of human health from the consumption of water and organisms is 1,200 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
129396
Region 3     
Malpaso Creek
 
Pollutant: Ammonia
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence (LOE) is available in the administrative record to assess this pollutant.
The following is a summary of the sample and exceedances for each beneficial use:

Based on LOEs summarizing total ammonia data (‘nitrogen, ammonia’ and ‘nitrogen as ammonia’) zero of the five samples exceed the EPA's Lifetime Health advisory level set to protect municipal and domestic supply 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 CWA section 303(d) List in the Water Quality Limited Segments category. This sample size is insufficient to determine an applicable beneficial use support rating with the power and confidence of the Listing Policy. In accordance with Table 3.1 of the Listing Policy, a minimum of 16 samples is needed to determine if a beneficial use is fully supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the samples exceed the water quality objectives and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 129396, Ammonia
Region 3     
Malpaso Creek
 
LOE ID: 183957
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: EPA's Lifetime Health advisory level for total ammonia is 30.0 mg/L as stated on page 8 of the 2012 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 a lifetime of exposure.'
Guideline Reference: 2018 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112596
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112596, Anthracene
Region 3     
Malpaso Creek
 
LOE ID: 157817
 
Pollutant: Anthracene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Anthracene.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Anthracene criteria for the protection of human health from the consumption of water and organisms is 9,600 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112597
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: This pollutant is being considered for placement on the Clean Water Act (CWA) section 303(d) List under section 3.1 of the Listing Policy.

A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of one sample exceeds the evaluation guideline for the municipal and domestic supply beneficial use. These data are insufficient to determine the applicable beneficial use support rating with the power and confidence required by the Listing Policy.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. A total of zero of one sample exceeds the evaluation guideline for the municipal and domestic supply beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112597, Arsenic
Region 3     
Malpaso Creek
 
LOE ID: 158177
 
Pollutant: Arsenic
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Arsenic.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Maximum Contaminant Level for Arsenic is 10 ug/L.
Guideline Reference: California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112599
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112599, Benzo(a)anthracene
Region 3     
Malpaso Creek
 
LOE ID: 159068
 
Pollutant: Benzo(a)anthracene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Benz(a)anthracene. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Benzo(a)anthracene criteria for the protection of human health from the consumption of water and organisms is 0.0044 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112598
Region 3     
Malpaso Creek
 
Pollutant: Benzo(a)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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112598, Benzo(a)pyrene
Region 3     
Malpaso Creek
 
LOE ID: 159166
 
Pollutant: Benzo(a)pyrene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Benzo(a)pyrene. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Benzo(a)Pyrene criteria for the protection of human health from the consumption of water and organisms is 0.0044 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112600
Region 3     
Malpaso Creek
 
Pollutant: Benzo[b]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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112600, Benzo[b]fluoranthene
Region 3     
Malpaso Creek
 
LOE ID: 159190
 
Pollutant: Benzo[b]fluoranthene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Benzo(b)fluoranthene. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Benzo(b)Fluoranthene criteria for the protection of human health from the consumption of water and organisms is 0.0044 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112601
Region 3     
Malpaso Creek
 
Pollutant: Benzo[k]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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112601, Benzo[k]fluoranthene
Region 3     
Malpaso Creek
 
LOE ID: 158889
 
Pollutant: Benzo[k]fluoranthene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Benzo(k)fluoranthene. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Benzo(k)Fluoranthene criteria for the protection of human health from the consumption of water and organisms is 0.0044 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112624
Region 3     
Malpaso Creek
 
Pollutant: Bifenthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112624, Bifenthrin
Region 3     
Malpaso Creek
 
LOE ID: 158943
 
Pollutant: Bifenthrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of bifenthrin does not exceed 0.0006 ug/L (Fojut et al., 2012).
Guideline Reference: Water quality criteria report for Bifenthrin. Phase III: application of the pesticide water quality criteria methodology.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112624, Bifenthrin
Region 3     
Malpaso Creek
 
LOE ID: 159171
 
Pollutant: Bifenthrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of bifenthrin does not exceed 0.0006 ug/L (Fojut et al., 2012).
Guideline Reference: Water quality criteria report for Bifenthrin. Phase III: application of the pesticide water quality criteria methodology.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112602
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112602, Cadmium
Region 3     
Malpaso Creek
 
LOE ID: 159228
 
Pollutant: Cadmium
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Cadmium.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Maximum Contaminant Level for cadmium is 0.005 mg/L (California Code of Regulations, Title 22).
Guideline Reference: California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112602, Cadmium
Region 3     
Malpaso Creek
 
LOE ID: 159548
 
Pollutant: Cadmium
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Cadmium.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112602, Cadmium
Region 3     
Malpaso Creek
 
LOE ID: 159936
 
Pollutant: Cadmium
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Cadmium.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112603
Region 3     
Malpaso Creek
 
Pollutant: Chlorpyrifos
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112603, Chlorpyrifos
Region 3     
Malpaso Creek
 
LOE ID: 161470
 
Pollutant: Chlorpyrifos
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).
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
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112603, Chlorpyrifos
Region 3     
Malpaso Creek
 
LOE ID: 161412
 
Pollutant: Chlorpyrifos
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).
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
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112631
Region 3     
Malpaso Creek
 
Pollutant: Chromium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'.Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112631, Chromium
Region 3     
Malpaso Creek
 
LOE ID: 161684
 
Pollutant: Chromium
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Chromium.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All inland surface waters, enclosed bays, and estuaries shall not contain concentrations of inorganic chemicals in excess of the maximum contaminant levels for primary drinking water standards specified in California Code of Regulations, Title 22, Division 4, Chapter 15, Sections 64431 and 64433.2.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Maximum Contaminant Level for total chromium is 0.05 mg/L (California Code of Regulations, Title 22).
Guideline Reference: California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-06 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112604
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112604, Chrysene (C1-C4)
Region 3     
Malpaso Creek
 
LOE ID: 161990
 
Pollutant: Chrysene (C1-C4)
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chrysene. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Chrysene criteria for the protection of human health from the consumption of water and organisms is 0.0044 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112605
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: This pollutant is being considered for placement on the Clean Water Act (CWA) section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

A total of three lines of evidence are available in the administrative record to assess this pollutant. A total of zero of four samples exceed the water quality objective for the cold freshwater habitat beneficial use, zero of four samples exceed the water quality objective for the municipal and domestic supply beneficial use and zero of four samples exceed the water quality objective for the warm freshwater habitat beneficial use. These data are insufficient to determine the applicable beneficial use support rating with the power and confidence required by the Listing Policy.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. A total of zero of four samples exceed the water quality objective for the cold freshwater habitat beneficial use, zero of four samples exceed the water quality objective for the municipal and domestic supply beneficial use and zero of four samples exceed the water quality objective for the warm freshwater habitat beneficial use. This does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112605, Copper
Region 3     
Malpaso Creek
 
LOE ID: 162200
 
Pollutant: Copper
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Copper.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-26 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112605, Copper
Region 3     
Malpaso Creek
 
LOE ID: 162170
 
Pollutant: Copper
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Copper.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-26 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112605, Copper
Region 3     
Malpaso Creek
 
LOE ID: 162224
 
Pollutant: Copper
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Copper.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Copper criteria for the protection of human health from the consumption of water and organisms is 1.300 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-26 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112628
Region 3     
Malpaso Creek
 
Pollutant: Cyfluthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112628, Cyfluthrin
Region 3     
Malpaso Creek
 
LOE ID: 163289
 
Pollutant: Cyfluthrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of cyfluthrin does not exceed 0.00005 ug/L (0.05 ng/L) more than once every three years on the average (Fojut et al., 2012).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2014-02-26 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112628, Cyfluthrin
Region 3     
Malpaso Creek
 
LOE ID: 163387
 
Pollutant: Cyfluthrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of cyfluthrin does not exceed 0.00005 ug/L (0.05 ng/L) more than once every three years on the average (Fojut et al., 2012).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2014-02-26 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112630
Region 3     
Malpaso Creek
 
Pollutant: Cyhalothrin, Lambda
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112630, Cyhalothrin, Lambda
Region 3     
Malpaso Creek
 
LOE ID: 167548
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of lambda-cyhalothrin does not exceed 0.0005 ug/L (0.5 ng/L) more than once every three years on the average (Fojut et al., 2012).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2014-02-26 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112630, Cyhalothrin, Lambda
Region 3     
Malpaso Creek
 
LOE ID: 167525
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of lambda-cyhalothrin does not exceed 0.0005 ug/L (0.5 ng/L) more than once every three years on the average (Fojut et al., 2012).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2014-02-26 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112625
Region 3     
Malpaso Creek
 
Pollutant: Cypermethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112625, Cypermethrin
Region 3     
Malpaso Creek
 
LOE ID: 163259
 
Pollutant: Cypermethrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of cypermethrin does not exceed 0.0002 ug/L (0.2 ng/L) more than once every three years on the average (Fojut et al. ,2012).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2014-02-26 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112625, Cypermethrin
Region 3     
Malpaso Creek
 
LOE ID: 163220
 
Pollutant: Cypermethrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of cypermethrin does not exceed 0.0002 ug/L (0.2 ng/L) more than once every three years on the average (Fojut et al. ,2012).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2014-02-26 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112629
Region 3     
Malpaso Creek
 
Pollutant: Deltamethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1, and single line of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the two water samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses.

A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the two water samples exceed the evaluation guideline applied to protect for each aquatic life beneficial use and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112629, Deltamethrin
Region 3     
Malpaso Creek
 
LOE ID: 163570
 
Pollutant: Deltamethrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the water quality threshold for Deltamethrin. Although a total of 4 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Deltamethrin is the USEPA Aquatic Life Benchmark of 0.0041 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Data for this waterbody was collected over the date range 2014-02-26 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112629, Deltamethrin
Region 3     
Malpaso Creek
 
LOE ID: 163524
 
Pollutant: Deltamethrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the water quality threshold for Deltamethrin. Although a total of 4 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Deltamethrin is the USEPA Aquatic Life Benchmark of 0.0041 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Data for this waterbody was collected over the date range 2014-02-26 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112606
Region 3     
Malpaso Creek
 
Pollutant: Diazinon
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.


Two lines of evidence are available in the administrative record to assess this pollutant. Zero of six samples exceed the evaluation guideline applied to protect aquatic life beneficial uses. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.


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.


This conclusion is based on the staff findings that:

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

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

3. Zero of the samples exceeded the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112606, Diazinon
Region 3     
Malpaso Creek
 
LOE ID: 163531
 
Pollutant: Diazinon
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Diazinon.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).
Guideline Reference: Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112606, Diazinon
Region 3     
Malpaso Creek
 
LOE ID: 163528
 
Pollutant: Diazinon
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Diazinon.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).
Guideline Reference: Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112607
Region 3     
Malpaso Creek
 
Pollutant: Dibenz[a,h]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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112607, Dibenz[a,h]anthracene
Region 3     
Malpaso Creek
 
LOE ID: 163807
 
Pollutant: Dibenz[a,h]anthracene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dibenz(a,h)anthracene. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Dibenzo(a, h)anthracene criteria for the protection of human health from the consumption of water and organisms is 0.0044 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112608
Region 3     
Malpaso Creek
 
Pollutant: Dyfonate (Fonofos or Fonophos)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112608, Dyfonate (Fonofos or Fonophos)
Region 3     
Malpaso Creek
 
LOE ID: 166721
 
Pollutant: Dyfonate (Fonofos or Fonophos)
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Fonofos.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fonofos is the maximum acceptable toxicant concentration (MATC) of 0.45 ug/L. The MATC is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 0.64 ug/L and the no observed effect concentration (NOEC) of 0.31 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112608, Dyfonate (Fonofos or Fonophos)
Region 3     
Malpaso Creek
 
LOE ID: 166792
 
Pollutant: Dyfonate (Fonofos or Fonophos)
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Fonofos.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fonofos is the maximum acceptable toxicant concentration (MATC) of 0.45 ug/L. The MATC is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 0.64 ug/L and the no observed effect concentration (NOEC) of 0.31 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
125790
Region 3     
Malpaso Creek
 
Pollutant: Escherichia coli (E. coli)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the ISWEBE Plan) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies. Therefore, this waterbody is being considered for placement on the CWA section 303(d) List under section 3.3 of the Listing Policy, as applicable, using the E. coli objective.

In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. E. coli populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, indicator bacteria do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of E. coli in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard.

Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address E. coli. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the CWA section 303(d) List, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy.

All samples are evaluated using the statistical threshold value (STV) water quality objective for water contact recreation (ISWEBE, SWRCB 2019). The water quality objective states that the STV shall not be exceeded by more than 10 percent of the samples collected in a calendar month. Where there are more than one samples collected within any six-week period, a geomean of those samples is calculated and evaluated using the geomean water quality objective for water contact recreation (ISWEBE, SWRCB 2019).

Although three lines of evidence are available in the administrative record to assess this pollutant, this decision is based upon evaluation of the E. coli data collected since 2010 which are most representative of existing conditions in the waterbody. Zero of the seven samples collected since 2010 exceed the STV water quality objective (see LOEs 149744 and 149866) and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. No geomeans could be calculated for these data. The data were collected between 2010 and 2018 and represent a range of hydrologic conditions (both wet and dry years). This sample count of data collected since 2010 is insufficient to determine beneficial use support in accordance with the Listing Policy.

Note, there is one line of evidence summarizing historic data (data collected prior to 2010) compared to the USEPA’s Ambient Water Quality Criteria for Bacteria (USEPA, 1986). Zero of the four historic samples exceed the USEPA criteria set to protect for water contact recreation. These data are not used for making this decision or used in the final use support ratings.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero out of the seven samples exceed water quality objective (ISWEBE, SWRCB 2019) for water contact recreation and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation: Although three lines of evidence are available in the administrative record to assess this pollutant, this decision is based upon evaluation of the E. coli data collected since 2010 which are most representative of existing conditions in the waterbody. Zero of the seven samples collected since 2010 exceed the STV water quality objective (see LOEs 149744 and 149866) and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. No geomeans could be calculated for these data. The data were collected between 2010 and 2018 and represent a range of hydrologic conditions (both wet and dry years). This sample count of data collected since 2010 is insufficient to determine beneficial use support in accordance with the Listing Policy.

Note, there is one line of evidence summarizing historic data (data collected prior to 2010) compared to the USEPA’s Ambient Water Quality Criteria for Bacteria (USEPA, 1986). Zero of the four historic samples exceed the USEPA criteria set to protect for water contact recreation. These data are not used for making this decision or used in the final use support ratings.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero out of the seven samples exceed water quality objective (ISWEBE, SWRCB 2019) for water contact recreation 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.
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 125790, Escherichia coli (E. coli)
Region 3     
Malpaso Creek
 
LOE ID: 149744
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Malpaso Creek to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all non-saline waters, is a Statistical Threshold Value (STV) of 320 cfu/100 mL. The applicable STV shall not be exceeded by more than 10 percent of the samples collected in a calendar month, calculated in a static manner (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): 203LOB010-REF
Temporal Representation: The samples were collected between the days of 2013-10-14 and 2016-03-06 .
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 125790, Escherichia coli (E. coli)
Region 3     
Malpaso Creek
 
LOE ID: 18313
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Escherichia coli.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
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 Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 125790, Escherichia coli (E. coli)
Region 3     
Malpaso Creek
 
LOE ID: 149866
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Malpaso Creek to determine beneficial use support and the results are as follows: 0 of the 3 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all non-saline waters, is a Statistical Threshold Value (STV) of 320 cfu/100 mL. The applicable STV shall not be exceeded by more than 10 percent of the samples collected in a calendar month, calculated in a static manner (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): 308-MALPA-31
Temporal Representation: The samples were collected between the days of 2011-05-07 and 2013-05-04 .
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
 
DECISION ID
112633
Region 3     
Malpaso Creek
 
Pollutant: Esfenvalerate/Fenvalerate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1, and single line of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the two water samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses.

A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the two water samples exceed the evaluation guideline applied to protect for each aquatic life beneficial use and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112633, Esfenvalerate/Fenvalerate
Region 3     
Malpaso Creek
 
LOE ID: 165760
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Esfenvalerate.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Esfenvalerate is the USEPA Aquatic Life Benchmark of 0.017 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-26 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112633, Esfenvalerate/Fenvalerate
Region 3     
Malpaso Creek
 
LOE ID: 165740
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Esfenvalerate.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Esfenvalerate is the USEPA Aquatic Life Benchmark of 0.017 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-26 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112622
Region 3     
Malpaso Creek
 
Pollutant: Ethion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112622, Ethion
Region 3     
Malpaso Creek
 
LOE ID: 165810
 
Pollutant: Ethion
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112622, Ethion
Region 3     
Malpaso Creek
 
LOE ID: 165708
 
Pollutant: Ethion
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112622, Ethion
Region 3     
Malpaso Creek
 
LOE ID: 165649
 
Pollutant: Ethion
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ethion.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA expected safe lifetime exposure limit in drinking water for Ethion, calculated using the IRIS Reference Dose, is 3.5 ug/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, 20% relative source contribution from drinking water, and 0.0005 mg/kg/day as the reference dose.
Guideline Reference: IRIS Reference Summary (Various Pollutants)
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112626
Region 3     
Malpaso Creek
 
Pollutant: Ethoprop
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the Clean Water Act (CWA) section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

A total of two lines of evidence are available in the administrative record to assess this pollutant. A total of zero of five samples exceed the water quality objective for the cold freshwater habitat beneficial use and zero of five samples exceed the evaluation guideline for the warm freshwater habitat beneficial use. These data are insufficient to determine the applicable beneficial use support rating with the power and confidence required by the Listing Policy.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. A total of zero of five samples exceed the water quality objective for the cold freshwater habitat beneficial use and zero of five samples exceed the evaluation guideline for the warm freshwater habitat beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112626, Ethoprop
Region 3     
Malpaso Creek
 
LOE ID: 166099
 
Pollutant: Ethoprop
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Ethoprop.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112626, Ethoprop
Region 3     
Malpaso Creek
 
LOE ID: 166077
 
Pollutant: Ethoprop
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Ethoprop.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
130206
Region 3     
Malpaso Creek
 
Pollutant: Fecal Coliform
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant.

Zero of the four samples exceed the water quality objective for non-contact recreation. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using table 3.2. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the four samples exceed the water quality objective for non-contact recreation and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 130206, Fecal Coliform
Region 3     
Malpaso Creek
 
LOE ID: 149767
 
Pollutant: Fecal Coliform
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Malpaso Creek to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 10% exceedance rate that is calculated for a 30-Day peroid.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section 3.3.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) 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 for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): 203LOB010-REF
Temporal Representation: The samples were collected between the days of 2013-10-14 and 2016-03-06 .
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112627
Region 3     
Malpaso Creek
 
Pollutant: Fenitrothion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112627, Fenitrothion
Region 3     
Malpaso Creek
 
LOE ID: 166138
 
Pollutant: Fenitrothion
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Fenitrothion.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fenitrothion is the USEPA Aquatic Life Benchmark of 0.087 ug/L for an invertebrate (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112627, Fenitrothion
Region 3     
Malpaso Creek
 
LOE ID: 166189
 
Pollutant: Fenitrothion
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Fenitrothion.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fenitrothion is the USEPA Aquatic Life Benchmark of 0.087 ug/L for an invertebrate (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112632
Region 3     
Malpaso Creek
 
Pollutant: Fenpropathrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1, and single line of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the five water samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses.

A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the two water samples exceed the evaluation guideline applied to protect for each aquatic life beneficial use and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112632, Fenpropathrin
Region 3     
Malpaso Creek
 
LOE ID: 166504
 
Pollutant: Fenpropathrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Fenpropathrin.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.06 ug/L for a fish (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112632, Fenpropathrin
Region 3     
Malpaso Creek
 
LOE ID: 166483
 
Pollutant: Fenpropathrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Fenpropathrin.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.06 ug/L for a fish (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112609
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112609, Fluoranthene
Region 3     
Malpaso Creek
 
LOE ID: 166617
 
Pollutant: Fluoranthene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Fluoranthene.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Fluoranthene criteria for the protection of human health from the consumption of water and organisms is 300 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112610
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112610, Fluorene
Region 3     
Malpaso Creek
 
LOE ID: 166662
 
Pollutant: Fluorene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Fluorene.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Fluorene criteria for the protection of human health from the consumption of water and organisms is 1,300 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112611
Region 3     
Malpaso Creek
 
Pollutant: Indeno[1,2,3-cd]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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112611, Indeno[1,2,3-cd]pyrene
Region 3     
Malpaso Creek
 
LOE ID: 167544
 
Pollutant: Indeno[1,2,3-cd]pyrene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Indeno(1,2,3-c,d)pyrene. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Indeno(1, 2, 3-C, D)Pyrene criteria for the protection of human health from the consumption of water and organisms is 0.0044 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112612
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under sections 3.1 of the Listing Policy. Under section 3.1 at least one line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant.

Zero of the 6 dissolved lead water samples exceed the water quality objective aquatic life beneficial uses.

One of the 6 total lead water samples exceed the evaluation guideline for Municipal and Domestic Supply.

This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of the 6 total lead water samples exceed the evaluation guideline for Municipal and Domestic Supply and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112612, Lead
Region 3     
Malpaso Creek
 
LOE ID: 168060
 
Pollutant: Lead
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 6
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 1 of 6 samples exceeded the water quality threshold for Lead.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Public Health Goal for lead in sources of drinking water is 0.0002 mg/L. (OEHHA 2009)
Guideline Reference: Public Health Goal for Lead in Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-06 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112612, Lead
Region 3     
Malpaso Creek
 
LOE ID: 168166
 
Pollutant: Lead
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Lead.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-06 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112612, Lead
Region 3     
Malpaso Creek
 
LOE ID: 168236
 
Pollutant: Lead
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Lead.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-06 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112613
Region 3     
Malpaso Creek
 
Pollutant: Malathion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.


Three lines of evidence are available in the administrative record to assess this pollutant. Zero of zero samples exceed the evaluation guideline applied to protect aquatic life beneficial uses. In this case, some samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Zero of five samples exceeded the USEPA drinking water health advisory. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.


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.


This conclusion is based on the staff findings that:

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

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

3. Zero of the samples exceeded the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112613, Malathion
Region 3     
Malpaso Creek
 
LOE ID: 168498
 
Pollutant: Malathion
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of malathion does not exceed 0.028 ug/L more than once every three years on the average (Faria et al., 2010).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112613, Malathion
Region 3     
Malpaso Creek
 
LOE ID: 168440
 
Pollutant: Malathion
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of malathion does not exceed 0.028 ug/L more than once every three years on the average (Faria et al., 2010).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112613, Malathion
Region 3     
Malpaso Creek
 
LOE ID: 168380
 
Pollutant: Malathion
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Malathion.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA drinking water health advisory for malathion is 500 ug/L.
Guideline Reference: 2018 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
130737
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant.

Three LOEs summarize water samples:
- Zero of eight water samples exceed the mercury evaluation guideline (National Recommended Water Quality Criteria, EPA 2016), set to protect for aquatic life beneficial uses.
- Zero of eight water samples exceed the mercury evaluation guideline (California Toxics Rule, 2000), set to protect for the municipal and domestic supply beneficial use.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. No water samples exceeded the evaluation guidelines, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 130737, Mercury
Region 3     
Malpaso Creek
 
LOE ID: 169381
 
Pollutant: Mercury
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Mercury.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents known to be deleterious to fish or wildlife (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The Criterion Continuous Concentration for freshwater aquatic life is 0.77 ug/L (National Recommended Water Quality Criteria, EPA 2016)
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 130737, Mercury
Region 3     
Malpaso Creek
 
LOE ID: 169542
 
Pollutant: Mercury
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Mercury.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents known to be deleterious to fish or wildlife (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The Criterion Continuous Concentration for freshwater aquatic life is 0.77 ug/L (National Recommended Water Quality Criteria, EPA 2016)
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 130737, Mercury
Region 3     
Malpaso Creek
 
LOE ID: 169545
 
Pollutant: Mercury
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Mercury.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The mercury criteria for the protection of human health from the consumption of water and organisms for mercury is 0.050 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112614
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: This pollutant is being considered for placement on the Clean Water Act (CWA) section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

A total of three lines of evidence are available in the administrative record to assess this pollutant. A total of zero of six samples exceed the water quality objective for the cold freshwater habitat beneficial use, zero of six samples exceed the evaluation guideline for the municipal and domestic supply beneficial use and zero of six samples exceed the water quality objective for the warm freshwater habitat beneficial use. These data are insufficient to determine the applicable beneficial use support rating with the power and confidence required by the Listing Policy.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. A total of zero of six samples exceed the water quality objective for the cold freshwater habitat beneficial use, zero of six samples exceed the evaluation guideline for the municipal and domestic supply beneficial use and zero of six samples exceed the water quality objective for the warm freshwater habitat beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112614, Nickel
Region 3     
Malpaso Creek
 
LOE ID: 171277
 
Pollutant: Nickel
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Nickel.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-06 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112614, Nickel
Region 3     
Malpaso Creek
 
LOE ID: 171175
 
Pollutant: Nickel
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Nickel.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-06 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112614, Nickel
Region 3     
Malpaso Creek
 
LOE ID: 171078
 
Pollutant: Nickel
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Nickel.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of inorganic chemicals in excess of the maximum contaminant levels for primary drinking water standards specified in California Code of Regulations, Title 22, Division 4, Chapter 15, Sections 64431 and 64433.2 (Water Quality Control Plan, Central Coast Basin)
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The maximum contaminant level of nickel in public water systems shall be 0.1 mg/L (California Code of Regulations, Title 22, Division 4, Chapter 15, Sections 64431).
Guideline Reference: California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-06 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
126819
Region 3     
Malpaso Creek
 
Pollutant: Nitrate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Seven lines of evidence are available in the administrative record to assess this pollutant. Lines of evidence for the pollutant name Nitrate and for the pollutant name Nitrogen, Nitrate are combined. Where the fraction is none or not recorded, staff assumed that the fraction is identical to that reported for pollutants of the same name, based on the analytical method. In these cases, sample and exceedance counts are summed for the purpose of making this decision.

Zero of the 13 samples exceed the Municipal & Domestic Supply water quality objective. Zero of the 9 samples exceed the evaluation guideline for Cold and Warm Freshwater Habitats. Insufficient information is available to determine a beneficial use support rating for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the water quality objectives and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using Table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 126819, Nitrate
Region 3     
Malpaso Creek
 
LOE ID: 172324
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
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 (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Technical approach to develop nutrient numeric endpoints for California, Tetra Tech, June 2006. The Central Coast Region numeric target for maximum nitrate concentration is based on the Tetra Tech NNE (Nutrient Numeric Endpoint) Model and CCAMP data for 193 sites, monitored monthly for at least 1 year between January 1998 and December 2006. The model numeric target for aquatic life habitats in the Central Coast Region is 1.0 mg/L Nitrate as N.
Guideline Reference: Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2016-05-07
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126819, Nitrate
Region 3     
Malpaso Creek
 
LOE ID: 172724
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
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 (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Technical approach to develop nutrient numeric endpoints for California, Tetra Tech, June 2006. The Central Coast Region numeric target for maximum nitrate concentration is based on the Tetra Tech NNE (Nutrient Numeric Endpoint) Model and CCAMP data for 193 sites, monitored monthly for at least 1 year between January 1998 and December 2006. The model numeric target for aquatic life habitats in the Central Coast Region is 1.0 mg/L Nitrate as N.
Guideline Reference: Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 126819, Nitrate
Region 3     
Malpaso Creek
 
LOE ID: 173012
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
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 (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Technical approach to develop nutrient numeric endpoints for California, Tetra Tech, June 2006. The Central Coast Region numeric target for maximum nitrate concentration is based on the Tetra Tech NNE (Nutrient Numeric Endpoint) Model and CCAMP data for 193 sites, monitored monthly for at least 1 year between January 1998 and December 2006. The model numeric target for aquatic life habitats in the Central Coast Region is 1.0 mg/L Nitrate as N.
Guideline Reference: Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2016-05-07
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126819, Nitrate
Region 3     
Malpaso Creek
 
LOE ID: 172307
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All inland surface waters, enclosed bays, and estuaries shall not contain concentrations of inorganic chemicals in excess of the maximum contaminant levels for primary drinking water standards specified in California Code of Regulations, Title 22, Division 4, Chapter 15, Sections 64431 and 64433.2.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Maximum Contaminant Level for nitrate (as N) 10.0 mg/L (California Code of Regulations, Title 22).
Guideline Reference: California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 126819, Nitrate
Region 3     
Malpaso Creek
 
LOE ID: 172905
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
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 (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Technical approach to develop nutrient numeric endpoints for California, Tetra Tech, June 2006. The Central Coast Region numeric target for maximum nitrate concentration is based on the Tetra Tech NNE (Nutrient Numeric Endpoint) Model and CCAMP data for 193 sites, monitored monthly for at least 1 year between January 1998 and December 2006. The model numeric target for aquatic life habitats in the Central Coast Region is 1.0 mg/L Nitrate as N.
Guideline Reference: Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 126819, Nitrate
Region 3     
Malpaso Creek
 
LOE ID: 172894
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All inland surface waters, enclosed bays, and estuaries shall not contain concentrations of inorganic chemicals in excess of the maximum contaminant levels for primary drinking water standards specified in California Code of Regulations, Title 22, Division 4, Chapter 15, Sections 64431 and 64433.2.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Maximum Contaminant Level for nitrate (as N) 10.0 mg/L (California Code of Regulations, Title 22).
Guideline Reference: California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2016-05-07
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126819, Nitrate
Region 3     
Malpaso Creek
 
LOE ID: 18467
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Nitrate as N.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin Objective for municipal and domestic supply uses of inland surface waters (Section II.A.2) states the following: waters shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Article 4, Chapter 15, Section 64435, Tables 2 and 3 as listed in Table 3-2. The maximum contaminant level listed in Table 3-2 (inorganic and fluoride concentrations not to be exceeded in domestic or municipal supply) for nitrate is 10.0 mg/L (NO3 as N).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
Objective/Criterion Reference: Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
 
DECISION ID
112615
Region 3     
Malpaso Creek
 
Pollutant: Organophosphate Pesticides
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of six water samples exceeded the aquatic life evaluation guideline for additive effects of chlorpyrifos and diazinon (Bailey et al., 1997).

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of six water samples exceeded the evaluation guideline, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112615, Organophosphate Pesticides
Region 3     
Malpaso Creek
 
LOE ID: 173794
 
Pollutant: Organophosphate Pesticides
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Organophosphorus Pesticides.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for the protection of aquatic life from the additive effects of the organophophate pesticides chlorpyrifos and diazinon is one toxic unit equivalent. A toxic unit equivalent is equal to the sum of chlorpyrifos and diazinon from a single sample, each having their reported concentration divided their respective evaluation guideline prior to being summed. If this results in a value greater than one, the sample is considered to be in exceedance of the water quality standard. (Bailey et al., 1997).
Guideline Reference: Joint acute toxicity of Diazinon and Chlorpyrifos to Ceriodaphnia dubia.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112615, Organophosphate Pesticides
Region 3     
Malpaso Creek
 
LOE ID: 173774
 
Pollutant: Organophosphate Pesticides
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Organophosphorus Pesticides.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for the protection of aquatic life from the additive effects of the organophophate pesticides chlorpyrifos and diazinon is one toxic unit equivalent. A toxic unit equivalent is equal to the sum of chlorpyrifos and diazinon from a single sample, each having their reported concentration divided their respective evaluation guideline prior to being summed. If this results in a value greater than one, the sample is considered to be in exceedance of the water quality standard. (Bailey et al., 1997).
Guideline Reference: Joint acute toxicity of Diazinon and Chlorpyrifos to Ceriodaphnia dubia.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112616
Region 3     
Malpaso Creek
 
Pollutant: Oxygen, Dissolved
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

Five lines of evidence are available in the administrative record to assess this pollutant.

Zero of six samples exceed the water quality objective for cold freshwater habitat (Basin Plan) and zero of three samples exceed the water quality objective for fish spawning (Basin Plan). Zero of six samples exceed the water quality objective for warm freshwater habitat (Basin Plan). Note that there is no difference between samples fractions ‘dissolved’ and ‘total,’ therefore sample and exceedance counts will be summed for the purpose of this decision.

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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of six samples exceed the objective for cold freshwater habitat, zero of three samples exceed the objective for fish spawning, and zero of the six samples exceed the objective for warm freshwater habitat. These do not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 112616, Oxygen, Dissolved
Region 3     
Malpaso Creek
 
LOE ID: 17976
 
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: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/1/2004-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 112616, Oxygen, Dissolved
Region 3     
Malpaso Creek
 
LOE ID: 175088
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2013-05-04
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 112616, Oxygen, Dissolved
Region 3     
Malpaso Creek
 
LOE ID: 175642
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Fish Spawning
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2013-05-04
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 112616, Oxygen, Dissolved
Region 3     
Malpaso Creek
 
LOE ID: 175616
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2013-05-04
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 112616, Oxygen, Dissolved
Region 3     
Malpaso Creek
 
LOE ID: 18251
 
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: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/1/2004-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
 
DECISION ID
112634
Region 3     
Malpaso Creek
 
Pollutant: Permethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112634, Permethrin
Region 3     
Malpaso Creek
 
LOE ID: 176925
 
Pollutant: Permethrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of permethrin does not exceed 0.002 ug/L (2 ng/L) more than once every three years on the average (Fojut et al., 2012).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112634, Permethrin
Region 3     
Malpaso Creek
 
LOE ID: 176923
 
Pollutant: Permethrin
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of permethrin does not exceed 0.002 ug/L (2 ng/L) more than once every three years on the average (Fojut et al., 2012).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF).
Temporal Representation: Date for this waterbody was collected over the date range 2013-10-14 to 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112618
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112618, Pyrene
Region 3     
Malpaso Creek
 
LOE ID: 180962
 
Pollutant: Pyrene
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Pyrene.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Pyrene criteria for the protection of human health from the consumption of water and organisms is 960 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112619
Region 3     
Malpaso Creek
 
Pollutant: Selenium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112619, Selenium
Region 3     
Malpaso Creek
 
LOE ID: 181096
 
Pollutant: Selenium
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Selenium.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All inland surface waters, enclosed bays, and estuaries shall not contain concentrations of inorganic chemicals in excess of the maximum contaminant levels for primary drinking water standards specified in California Code of Regulations, Title 22, Division 4, Chapter 15, Sections 64431 and 64433.2.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Maximum Contaminant Level for selenium is 0.05 mg/L (California Code of Regulations, Title 22).
Guideline Reference: California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-26 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112619, Selenium
Region 3     
Malpaso Creek
 
LOE ID: 181122
 
Pollutant: Selenium
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Selenium.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The criterion continuous concentration to protect aquatic life in freshwater is 0.005 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-26 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112619, Selenium
Region 3     
Malpaso Creek
 
LOE ID: 180857
 
Pollutant: Selenium
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Selenium.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The criterion continuous concentration to protect aquatic life in freshwater is 0.005 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-26 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112620
Region 3     
Malpaso Creek
 
Pollutant: Silver
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112620, Silver
Region 3     
Malpaso Creek
 
LOE ID: 181385
 
Pollutant: Silver
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Silver.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion maximum concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-12-12 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112620, Silver
Region 3     
Malpaso Creek
 
LOE ID: 181546
 
Pollutant: Silver
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Silver.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion maximum concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-12-12 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
126206
Region 3     
Malpaso Creek
 
Pollutant: Temperature, water
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the Clean Water Act (CWA) section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

A total of two lines of evidence are available in the administrative record to assess this pollutant. A total of zero of seven samples exceed the evaluation guideline (Moyle 1976) applied to protect the cold freshwater habitat beneficial use. The readily available data and information are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

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.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. A total of zero of seven samples exceed the evaluation guideline applied to protect the cold freshwater habitat beneficial use and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 126206, Temperature, water
Region 3     
Malpaso Creek
 
LOE ID: 216943
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Temperature.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The optimum range for growth and completion of most life stages of rainbow trout is 13-21 degrees Celsius (Moyle 1976).
Guideline Reference: Inland Fishes of California
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2013-05-04
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126206, Temperature, water
Region 3     
Malpaso Creek
 
LOE ID: 18632
 
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: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Water Temperature.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: Inland Fishes of California
 
Spatial Representation: Data for this line of evidence for Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
 
DECISION ID
112595
Region 3     
Malpaso Creek
 
Pollutant: Urea
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112595, Urea
Region 3     
Malpaso Creek
 
LOE ID: 182965
 
Pollutant: Urea
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Urea.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Urea is the USEPA Aquatic Life Benchmark of 11,500 ug/L for a nonvascular plant (acute) for Urea sulfate.
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112595, Urea
Region 3     
Malpaso Creek
 
LOE ID: 156416
 
Pollutant: Urea
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Urea.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Urea is the USEPA Aquatic Life Benchmark of 11,500 ug/L for a nonvascular plant (acute) for Urea sulfate.
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2013-10-14 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112621
Region 3     
Malpaso Creek
 
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
 
Regional Board Conclusion: This pollutant is being considered for placement on the Clean Water Act (CWA) section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

A total of two lines of evidence are available in the administrative record to assess this pollutant. A total of zero of five samples exceed the water quality objective for the cold freshwater habitat beneficial use and zero of five samples exceed the water quality objective for the warm freshwater habitat beneficial use. These data are insufficient to determine the applicable beneficial use support rating with the power and confidence required by the Listing Policy.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. A total of zero of five samples exceed the water quality objective for the cold freshwater habitat beneficial use and zero of five samples exceed the water quality objective for the warm freshwater habitat beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 112621, Zinc
Region 3     
Malpaso Creek
 
LOE ID: 156825
 
Pollutant: Zinc
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Zinc.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-06 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
Line of Evidence (LOE) for Decision ID 112621, Zinc
Region 3     
Malpaso Creek
 
LOE ID: 156601
 
Pollutant: Zinc
LOE Subgroup: Ancillary Line of Evidence
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed ASBS Regional Reference Site Monitoring data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Zinc.
Data Reference: Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (203LOB010-REF)
Temporal Representation: The samples were collected between the dates of 2014-02-06 and 2016-03-06
Environmental Conditions:
QAPP Information: No QAPP Received. Data will be assessed as ancillary evidence.
QAPP Information Reference(s): The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.
 
 
DECISION ID
112617
Region 3     
Malpaso Creek
 
Pollutant: pH
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

Ten lines of evidence is available in the administrative record to assess this pollutant. Zero of the 7 samples exceed the maximum pH water quality objective for Cold and Warm Freshwater Habitat, Municipal and Domestic Supply, Contact and Non-contact Recreation beneficial uses. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using Table 3.2 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the 7 samples exceed the maximum pH water quality objective for Cold and Warm Freshwater Habitat, Municipal and Domestic Supply, Contact and Non-contact Recreation 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 19115
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 19116
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Municipal and Domestic Supply Objectives, Section II.A.2.a states the following: The pH value shall neither be depressed below 6.5 or raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 19133
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 19134
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 19132
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Malpaso Creek was collected at 1 monitoring site [ 308-MALPA-31 - Malpaso Creek]
Temporal Representation: Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 178532
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for municipal and domestic supply (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2013-05-04
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 178531
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for water contact recreation (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2013-05-04
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 178861
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for cold fresh water habitat (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 7.0 nor raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2013-05-04
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 177993
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for warm fresh water habitat (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 7.0 nor raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2013-05-04
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 112617, pH
Region 3     
Malpaso Creek
 
LOE ID: 178115
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed MBNMS Snapshot Day data for Malpaso Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (308-MALPA-31)
Temporal Representation: The samples were collected between the dates of 2011-05-07 and 2013-05-04
Environmental Conditions:
QAPP Information: Monterey Bay NMS. 2003. California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): California Coast Wide Snapshot Day 2003 Quality Assurance Project Plan (QAPP)