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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name: Pacheco Creek
Water Body ID: CAR3053002020020103133745
Water Body Type: River & Stream
 
DECISION ID
130219
Region 3     
Pacheco Creek
 
Pollutant: Fecal Coliform
Final Listing Decision: Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2018)
Revision Status Revised
Reason for Delisting: Applicable WQS attained; due to change in WQS
TMDL Name: Pajaro River Fecal Coliform (including San Benito R., Llagas Cr., and Tequesquita Slough)
TMDL Project Code: 669
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the CWA section 303(d) List under section 4 of the Listing Policy due to a change in water quality standards.

The State Water Boards 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: where the salinity level of a waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies; and where the salinity level of a waterbody is greater than 1 part per thousand 95 percent or more of the time, the Enterococci bacteria objective applies.

These objectives supersede the fecal coliform water quality objective for water contact recreation. Consequently, the fecal coliform objective for water contact recreation is no longer applicable to this waterbody and those LOEs have been removed from this decision. Therefore, this waterbody is being removed from the CWA section 303(d) List under section 4 of the Listing Policy due to a change in water quality standards.

However, two lines of evidence (LOEs) are available in the administrative record to assess this pollutant and the non-contact recreation use. Therefore, 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.

Zero of the 49 samples exceed the water quality objective for non-contact recreation.

After review of the available data and information for the non-contact recreation beneficial use, RWQCB staff concludes that the water body-pollutant combination should not be placed on the CWA section 303(d) List because applicable water quality standards for the pollutant 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 49 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 be removed from the CWA section 303(d) List under section 4 of the Listing Policy due to a change in water quality standards.
 
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 130219, Fecal Coliform
Region 3     
Pacheco Creek
 
LOE ID: 150286
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacheco Creek to determine beneficial use support and the results are as follows: 0 of the 22 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: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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): 305PAC
Temporal Representation: The samples were collected between the days of 2011-01-13 and 2017-12-05 .
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 130219, Fecal Coliform
Region 3     
Pacheco Creek
 
LOE ID: 10165
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 27
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 27 samples exceed the criterion for Coliform, Fecal.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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: 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 (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
 
DECISION ID
107503
Region 3     
Pacheco Creek
 
Pollutant: Turbidity
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Sources: No Source Analysis Available
Expected TMDL Completion Date: 2035
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the Clean Water Act (CWA) section 303(d) List under section 4.2 of the Listing Policy. Under section 4.2 a single line of evidence is necessary to assess listing status.

A total of eight lines of evidence are available in the administrative record to assess this pollutant. Sample and exceedance counts for the lines of evidence with the fraction identified as “none” or “not recorded” are grouped together with those having the fraction “total”, based on the analytical method used. Once summed, a total of 43 of 185 samples exceed the evaluation guideline for cold freshwater habitat (Sigler et al. 1984) and 41 of 185 samples exceed the evaluation guideline for warm freshwater habitat (Shoup, D.E. and Wahl D.H., 2009) used to interpret the water quality objectives for the aquatic life beneficial uses. In addition, A recent publication (Steelhead/Rainbow Trout (Oncorhynchus mykiss) Resources South of the Golden Gate, California (Becker, G.S and I.J Reining, October 2008) identifies Pacheco Creek as having Definite run or population . Therefore this Turbidity Evaluation Guideline is relevant to the waterbody.

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

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 43 of 185 samples exceed the evaluation guideline for cold freshwater habitat and 41 of 185 samples exceed the evaluation guideline for warm freshwater habitat and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 107503, Turbidity
Region 3     
Pacheco Creek
 
LOE ID: 13700
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 17
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 17 of 36 samples exceed the criterion for Turbidity(NTU).
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107503, Turbidity
Region 3     
Pacheco Creek
 
LOE ID: 12051
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 20
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 3 of 20 samples exceed the criterion for Turbidity(NTU).
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107503, Turbidity
Region 3     
Pacheco Creek
 
LOE ID: 17504
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 107
Number of Exceedances: 21
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 21 of 107 samples exceed the criterion for Turbidity(NTU).
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 4 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., Walnut]
Temporal Representation: Data was collected over the time period 9/28/2005-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107503, Turbidity
Region 3     
Pacheco Creek
 
LOE ID: 183217
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 2 of 22 samples exceeded the water quality threshold for Turbidity.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. (Basin Plan)
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Turbidities of 25 NTU or greater can cause a reduction in juvenile salmonid growth due to interference with their ability to find food (Sigler et al. 1984).
Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
 
Spatial Representation: The samples were collected at 1 monitoring site (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107503, Turbidity
Region 3     
Pacheco Creek
 
LOE ID: 12052
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 20
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 3 of 20 samples exceed the criterion for Turbidity(NTU).
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107503, Turbidity
Region 3     
Pacheco Creek
 
LOE ID: 13701
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 17
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 17 of 36 samples exceed the criterion for Turbidity(NTU).
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107503, Turbidity
Region 3     
Pacheco Creek
 
LOE ID: 183136
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Turbidity.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009).
Guideline Reference: The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
 
Spatial Representation: The samples were collected at 1 monitoring site (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107503, Turbidity
Region 3     
Pacheco Creek
 
LOE ID: 17505
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 107
Number of Exceedances: 21
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 21 of 107 samples exceed the criterion for Turbidity(NTU).
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 4 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., Walnut]
Temporal Representation: Data was collected over the time period 9/28/2005-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
 
DECISION ID
107497
Region 3     
Pacheco Creek
 
Pollutant: Oxygen, Dissolved
Final Listing Decision: Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Sources: Agriculture | Domestic Animals/Livestock | Natural Sources
TMDL Name: Pajaro River Watershed Nutrients
TMDL Project Code: 999
Expected TMDL Completion Date: 2027
Date TMDL Approved by USEPA: 10/06/2016
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the section 303(d) List under sections 2.2 and 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

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

One hundred fifty-one of 401 samples exceed the cold freshwater habitat water quality objective (Basin Plan) and three of 24 samples exceed the water quality objective for fish spawning (Basin Plan). Thirty-nine of 401 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.

Previous decisions (pre-2020) included dissolved oxygen saturation LOEs as ancillary evidence. This decision will no longer include dissolved oxygen saturation and these LOEs will be retired next cycle.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One hundred fifty-one of 401 samples exceed the cold freshwater habitat objective. This exceeds the allowable frequency listed in Table 4.2 of the Listing Policy.
4. The Pajaro River watershed nutrients TMDL was adopted by USEPA on October 6, 2016.
5. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) List because applicable water quality standards for the pollutant are being exceeded.

Furthermore, this pollutant waterbody combination should be placed in the 'Being Addressed' portion of the 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard.
 
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 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 175156
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Fish Spawning
 
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 SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-30 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 174820
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
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 SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-30 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 174816
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
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 SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-30 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 175162
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 3 of 22 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 174821
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 175158
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Fish Spawning
 
Number of Samples: 22
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 3 of 22 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 12111
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 12285
 
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: 31
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 3 of 31 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 17837
 
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: 344
Number of Exceedances: 145
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 145 of 344 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 5 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 12284
 
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: 31
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 3 of 31 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 12110
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107497, Oxygen, Dissolved
Region 3     
Pacheco Creek
 
LOE ID: 17838
 
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: 344
Number of Exceedances: 36
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 36 of 344 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 5 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
 
DECISION ID
107506
Region 3     
Pacheco Creek
 
Pollutant: Aluminum
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. One of the 3 water samples exceed the evaluation guidelines for applied to protect aquatic life beneficial use(s). Zero of the 5 water samples exceed the water quality objective for agriculture supply beneficial uses (AGR).

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 five 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 3 water samples exceeds the evaluation guidelines for applied to protect aquatic life beneficial use(s) 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 107506, Aluminum
Region 3     
Pacheco Creek
 
LOE ID: 233037
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Aluminum.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 National Recommended Water Quality Criteria for the protection of aquatic life from aluminum, expressed in terms of total recoverable metal in the water column, is the chronic continuous concentration (4-day average) of 87 ug/L.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: The samples were collected at 1 monitoring site (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107506, Aluminum
Region 3     
Pacheco Creek
 
LOE ID: 233040
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Aluminum.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 National Recommended Water Quality Criteria for the protection of aquatic life from aluminum, expressed in terms of total recoverable metal in the water column, is the chronic continuous concentration (4-day average) of 87 ug/L.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: The samples were collected at 1 monitoring site (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107506, Aluminum
Region 3     
Pacheco Creek
 
LOE ID: 157315
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Aluminum.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for aluminum for irrigation supply as 5.0 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
127631
Region 3     
Pacheco Creek
 
Pollutant: Ammonia
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(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.

Nine lines of evidence (LOEs) are available in the administrative record to assess this pollutant.
Sample and exceedance counts for the lines of evidence with the fraction identified as “none” or “not recorded” are grouped together with those having the fraction “total”, based on the analytical method used. The following is a summary of the sample and exceedances for each beneficial use:

Based on LOEs summarizing un-ionized ammonia data, zero of the 40 samples exceed the water quality objective (Basin Plan) set to protect aquatic life.

Based on LOEs summarizing total ammonia data (‘nitrogen, ammonia’ and ‘nitrogen as ammonia’) zero of the 12 samples exceed the EPA's Aquatic Life Ambient Water Quality Criteria set to protect aquatic life. 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.

Based on LOEs summarizing total ammonia data (‘nitrogen, ammonia’ and ‘nitrogen as ammonia’) zero of the 481 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 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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 127631, Ammonia
Region 3     
Pacheco Creek
 
LOE ID: 17797
 
Pollutant: Ammonia as Nitrogen
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 432
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 432 samples exceed the criterion for Ammonia As N, Total.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: USEPA Health Advisory 2006 Edition of the Drinking Water Standards and Health Advisories (EPA 822-R-06-013, 2006).
Objective/Criterion Reference: 2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
 
Evaluation Guideline: EPA's Lifetime Health advisory level for total ammonia is 30.0 mg/L as stated on page 8 of the 2006 edition of the drinking water standards and health advisories. This Advisory Level is defined as "the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure."
Guideline Reference: 2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 8 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut, PC-SFL PC-DOW Casa de Fruta]
Temporal Representation: Data was collected over the time period 10/1/2002-3/13/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 127631, Ammonia
Region 3     
Pacheco Creek
 
LOE ID: 9322
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 27
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 27 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 127631, Ammonia
Region 3     
Pacheco Creek
 
LOE ID: 9321
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 27
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 27 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 127631, Ammonia
Region 3     
Pacheco Creek
 
LOE ID: 9320
 
Pollutant: Ammonia as Nitrogen
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 27
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 27 samples exceed the criterion for Ammonia as N, Total.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: USEPA Health Advisory 2006 Edition of the Drinking Water Standards and Health Advisories (EPA 822-R-06-013, 2006).
Objective/Criterion Reference: 2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
 
Evaluation Guideline: EPA's Lifetime Health advisory level for total ammonia is 30.0 mg/L as stated on page 8 of the 2006 edition of the drinking water standards and health advisories. This Advisory Level is defined as "the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure."
Guideline Reference: 2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 127631, Ammonia
Region 3     
Pacheco Creek
 
LOE ID: 184166
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-02-10 and 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127631, Ammonia
Region 3     
Pacheco Creek
 
LOE ID: 219544
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and the results are as follows: 0 of the 13 samples exceeded the water quality threshold for Ammonia as N, Unionized. Although a total of 21 samples were collected, 8 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: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin General Objective, Chapter 3, Section 3.3.2 (Objectives for all Inland Surface Waters, Enclosed Bays, and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/L (as N) in receiving waters (page 32).
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 (305PAC).
Temporal Representation: Data for this waterbody was collected over the date range 2011-01-13 to 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127631, Ammonia
Region 3     
Pacheco Creek
 
LOE ID: 219424
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and the results are as follows: 0 of the 13 samples exceeded the water quality threshold for Ammonia as N, Unionized. Although a total of 21 samples were collected, 8 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: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin General Objective, Chapter 3, Section 3.3.2 (Objectives for all Inland Surface Waters, Enclosed Bays, and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/L (as N) in receiving waters (page 32).
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 (305PAC).
Temporal Representation: Data for this waterbody was collected over the date range 2011-01-13 to 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127631, Ammonia
Region 3     
Pacheco Creek
 
LOE ID: 184168
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127631, Ammonia
Region 3     
Pacheco Creek
 
LOE ID: 184377
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-02-10 and 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107487
Region 3     
Pacheco 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 two lines of evidence are available in the administrative record to assess this pollutant. A total of zero of three samples exceed the water quality objective for the agricultural supply beneficial use and zero of three samples exceed 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 three samples exceed the water quality objective for the agricultural supply beneficial use and zero of three samples exceed 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 107487, Arsenic
Region 3     
Pacheco Creek
 
LOE ID: 158105
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Arsenic.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107487, Arsenic
Region 3     
Pacheco Creek
 
LOE ID: 158685
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Arsenic.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for arsenic for irrigation supply as 0.1 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107488
Region 3     
Pacheco Creek
 
Pollutant: Boron
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 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the 37 boron (dissolved) samples and zero of the 10 boron (total) samples exceed the Agricultural Supply water quality objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the 37 boron (dissolved) samples and zero of the 10 boron (total) exceed the Agricultural Supply water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 107488, Boron
Region 3     
Pacheco Creek
 
LOE ID: 9327
 
Pollutant: Boron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 15
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Boron, dissolved.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in Table 3.4 (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). Table 3-4 (page III-9) lists the maximum concentration for boron for irrigation supply is 0.75 mg/L.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/25/2005-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107488, Boron
Region 3     
Pacheco Creek
 
LOE ID: 159515
 
Pollutant: Boron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 10 samples exceeded the water quality threshold for Boron.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for boron for irrigation supply as 0.75 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-01-05 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107488, Boron
Region 3     
Pacheco Creek
 
LOE ID: 159370
 
Pollutant: Boron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Boron.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for boron for irrigation supply as 0.75 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107489
Region 3     
Pacheco 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: 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 107489, Cadmium
Region 3     
Pacheco Creek
 
LOE ID: 160274
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-03-02
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107489, Cadmium
Region 3     
Pacheco Creek
 
LOE ID: 160372
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-03-02
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107489, Cadmium
Region 3     
Pacheco Creek
 
LOE ID: 160220
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-03-02
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107489, Cadmium
Region 3     
Pacheco Creek
 
LOE ID: 160268
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for cadmium for irrigation supply as 0.01 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-03-02
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107490
Region 3     
Pacheco Creek
 
Pollutant: Chloride
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(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.

Three lines of evidence is available in the administrative record to assess this pollutant. Zero of 10 the chloride (dissolved) samples, zero of 15 of the chloride (fraction=none) samples, and zero of the 12 chloride (total) samples exceed the Agricultural Supply water quality objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 10 the chloride (dissolved) samples, zero of 15 of the chloride (fraction=none) samples, and zero of the 12 chloride (total) samples exceed the Agricultural Supply water quality objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using Table 3.2.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 107490, Chloride
Region 3     
Pacheco Creek
 
LOE ID: 160709
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines listed in the Central Coast Basin Plan and identified as the level at which severe problems may occur when chloride exceeds 106 mg/L in irrigation supply water.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2011-12-13
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107490, Chloride
Region 3     
Pacheco Creek
 
LOE ID: 160686
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 10 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines listed in the Central Coast Basin Plan and identified as the level at which severe problems may occur when chloride exceeds 106 mg/L in irrigation supply water.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-01-05 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107490, Chloride
Region 3     
Pacheco Creek
 
LOE ID: 9328
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 15
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Chloride.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when chloride exceeds 106 mg/L in irrigation supply water.
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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/25/2005-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
 
DECISION ID
107505
Region 3     
Pacheco 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: 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 four lines of evidence are available in the administrative record to assess this pollutant. A total of zero of three samples exceed the water quality objective for the agricultural supply beneficial use, zero of one sample exceeds the water quality objective for the cold freshwater habitat beneficial use, zero of three samples exceed the water quality objective for the municipal and domestic supply beneficial use and zero of one sample exceeds 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 three samples exceed the water quality objective for the agricultural supply beneficial use, zero of one sample exceeds the water quality objective for the cold freshwater habitat beneficial use, zero of three samples exceed the water quality objective for the municipal and domestic supply beneficial use and zero of one sample exceeds 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 107505, Chromium
Region 3     
Pacheco Creek
 
LOE ID: 161738
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-12-05 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107505, Chromium
Region 3     
Pacheco Creek
 
LOE ID: 161746
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Chromium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for chromium for irrigation supply is 0.10 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107505, Chromium
Region 3     
Pacheco Creek
 
LOE ID: 161808
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-12-05 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107505, Chromium
Region 3     
Pacheco Creek
 
LOE ID: 161834
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Chromium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107492
Region 3     
Pacheco 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 four lines of evidence are available in the administrative record to assess this pollutant. A total of zero of 22 samples exceed the water quality objective for the agricultural supply beneficial use, zero of 10 samples exceed the water quality objective for the cold freshwater habitat beneficial use, zero of 22 samples exceed the water quality objective for the municipal and domestic supply beneficial use and zero of 10 samples exceed the water quality objective for the warm freshwater habitat 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 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 22 samples exceed the water quality objective for the agricultural supply beneficial use, zero of 10 samples exceed the water quality objective for the cold freshwater habitat beneficial use, zero of 22 samples exceed the water quality objective for the municipal and domestic supply beneficial use and zero of 10 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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 107492, Copper
Region 3     
Pacheco Creek
 
LOE ID: 163087
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Copper.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for copper for irrigation supply as 0.2 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107492, Copper
Region 3     
Pacheco Creek
 
LOE ID: 162997
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and the results are as follows: 0 of the 10 samples exceeded the water quality threshold for Copper. Although a total of 22 samples were collected, 12 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: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC).
Temporal Representation: Data for this waterbody was collected over the date range 2011-01-13 to 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107492, Copper
Region 3     
Pacheco Creek
 
LOE ID: 163066
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Copper.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107492, Copper
Region 3     
Pacheco Creek
 
LOE ID: 162408
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and the results are as follows: 0 of the 10 samples exceeded the water quality threshold for Copper. Although a total of 22 samples were collected, 12 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: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC).
Temporal Representation: Data for this waterbody was collected over the date range 2011-01-13 to 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
125813
Region 3     
Pacheco 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 two 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. Four of the 22 samples collected since 2010 exceed the STV water quality objective (see LOE 150305) 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). Four of the 15 historic samples exceed the USEPA criteria set to protect for water contact recreation (see LOE 10220). 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. Four out of the 22 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 two 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. Four of the 22 samples collected since 2010 exceed the STV water quality objective (see LOE 150305) 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). Four of the 15 historic samples exceed the USEPA criteria set to protect for water contact recreation (see LOE 10220). 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. Four out of the 22 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 125813, Escherichia coli (E. coli)
Region 3     
Pacheco Creek
 
LOE ID: 150305
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 22
Number of Exceedances: 4
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacheco Creek to determine beneficial use support and the results are as follows: 4 of the 22 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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): 305PAC
Temporal Representation: The samples were collected between the days of 2011-01-13 and 2017-12-05 .
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 125813, Escherichia coli (E. coli)
Region 3     
Pacheco Creek
 
LOE ID: 10220
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 15
Number of Exceedances: 4
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 4 of 15 samples exceed the criterion for Escherichia coli.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/25/2005-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
 
DECISION ID
107493
Region 3     
Pacheco 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: 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 107493, Lead
Region 3     
Pacheco Creek
 
LOE ID: 167794
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-03-02
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107493, Lead
Region 3     
Pacheco Creek
 
LOE ID: 233213
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All inland surface waters, enclosed bays, and estuaries shall not contain concentrations of organic 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, Article 5.5, Section 64444, Table 64444-A.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Maximum Contaminant Level for lead is 15 ug/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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-03-02
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107493, Lead
Region 3     
Pacheco Creek
 
LOE ID: 167934
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for lead for livestock watering as 0.1 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-03-02
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107493, Lead
Region 3     
Pacheco Creek
 
LOE ID: 167945
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-03-02
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107494
Region 3     
Pacheco Creek
 
Pollutant: Manganese
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 one line of evidence is available in the administrative record to assess this pollutant. A total of zero of three samples exceed the water quality objective for the agricultural 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.

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 three samples exceed the water quality objective for the agricultural 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:
 
 
Line of Evidence (LOE) for Decision ID 107494, Manganese
Region 3     
Pacheco Creek
 
LOE ID: 169011
 
Pollutant: Manganese
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Manganese.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan identified as the maximum concentration for manganese for irrigation supply as 0.2 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
130742
Region 3     
Pacheco 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.

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

Five LOEs summarize water samples:
- Zero of three water samples exceed the mercury evaluation guideline (National Recommended Water Quality Criteria, EPA 2016), set to protect for aquatic life beneficial uses.
- Zero of three water samples exceed the mercury evaluation guideline (California Toxics Rule, 2000), set to protect for the commercial or recreational collection of fish, shellfish, or organisms beneficial use.
- Zero of three water samples exceed the mercury water quality objective (Basin Plan), set to protect for agricultural supply beneficial use.
- Zero of three 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 130742, Mercury
Region 3     
Pacheco Creek
 
LOE ID: 169258
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Mercury.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for mercury for livestock watering as 0.01 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 130742, Mercury
Region 3     
Pacheco Creek
 
LOE ID: 169225
 
Pollutant: Mercury
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Mercury.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 130742, Mercury
Region 3     
Pacheco Creek
 
LOE ID: 169197
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Mercury.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Human health risk associated with organism consumption is 0.051 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 130742, Mercury
Region 3     
Pacheco Creek
 
LOE ID: 168834
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Mercury.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 130742, Mercury
Region 3     
Pacheco Creek
 
LOE ID: 169392
 
Pollutant: Mercury
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Mercury.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107495
Region 3     
Pacheco 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 five lines of evidence are available in the administrative record to assess this pollutant. A total of zero of three samples exceed the water quality objective for the agricultural supply beneficial use, zero of three samples exceed the water quality objective for the cold freshwater habitat beneficial use, zero of three samples exceed the water quality objective for the commercial or recreational collection of fish, shellfish, or organisms beneficial use, zero of three samples exceed the evaluation guideline for the municipal and domestic supply beneficial use and zero of three 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 three samples exceed the water quality objective for the agricultural supply beneficial use, zero of three samples exceed the water quality objective for the cold freshwater habitat beneficial use, zero of three samples exceed the water quality objective for the commercial or recreational collection of fish, shellfish, or organisms beneficial use, zero of three samples exceed the evaluation guideline for the municipal and domestic supply beneficial use and zero of three 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 107495, Nickel
Region 3     
Pacheco Creek
 
LOE ID: 170712
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Nickel.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107495, Nickel
Region 3     
Pacheco Creek
 
LOE ID: 170816
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Nickel.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for nickel for irrigation supply as 0.2 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107495, Nickel
Region 3     
Pacheco Creek
 
LOE ID: 170824
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Nickel.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107495, Nickel
Region 3     
Pacheco Creek
 
LOE ID: 170924
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Nickel.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107495, Nickel
Region 3     
Pacheco Creek
 
LOE ID: 170795
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Nickel.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Human health risk associated with organism consumption is 4.6 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
127305
Region 3     
Pacheco 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.

Fourteen 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.

Agricultural Supply beneficial use: Zero of the 520 nitrate and zero of the 12 nitrate/nitrite samples exceed the water quality objective.

Municipal and Domestic Supply beneficial use: Zero of the 520 nitrate and zero of the 24 nitrate/nitrite samples exceed the water quality objective.

Aquatic Life beneficial uses: There is insufficient information available to make a use support determination for Cold and Warm Freshwater Habitats. Although 13 of the 22 nitrate and five of the 12 nitrate/nitrite samples exceed the evaluation guideline used to interpret the narrative water quality objective for bio-stimulatory substances (Central Coast Region Technical Report, 2010), there is no supporting data, such as dissolved oxygen or chlorophyll a measurements, to support the conclusion that nitrate contributes to or causes a bio-stimulatory effect in this waterbody. Therefore, the weight of evidence approach cannot be applied in accordance with section 3.11 of the Listing Policy and the use rating is set to insufficient information.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero samples exceed the water quality objectives for Municipal and Domestic Supply and Agricultural supply. Neither of these exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation: 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 for Municipal and Domestic Supply and Agricultural supply. Neither of these exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
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 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 171553
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 5
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 5 of 12 samples exceeded the water quality threshold for Nitrate + Nitrite as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2011-12-13
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 171680
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Nitrate + Nitrite as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 + nitrite (as N) is 10. 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2011-12-13
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 171572
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 5
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 5 of 12 samples exceeded the water quality threshold for Nitrate + Nitrite as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2011-12-13
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 171536
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Nitrate + Nitrite as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for nitrate + nitrite for livestock watering as 100 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2011-12-13
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 172212
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 13
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 13 of 22 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 172181
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines listed in the Central Coast Basin Plan and identified as the level that severe problems may occur when nitrate exceeds 30 mg/L (NO3 as N) in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 173183
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 172496
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 13
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 13 of 22 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 9324
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 27
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 27 samples exceed the criterion for Nitrate as N.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 17676
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 435
Number of Exceedances: 5
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 5 of 435 samples exceed the criterion for Nitrate as N.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin Objective for municipal and domestic supply uses of inland surface waters (Section II.A.2) states the following: waters shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Article 4, Chapter 15, Section 64435, Tables 2 and 3 as listed in Table 3-2. The maximum contaminant level listed in Table 3-2 (inorganic and fluoride concentrations not to be exceeded in domestic or municipal supply) for nitrate is 10.0 mg/L (NO3 as N).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
Objective/Criterion Reference: Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 8 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut, PC-SFL PC-DOW Casa de Fruta]
Temporal Representation: Data was collected over the time period 10/1/2002-3/13/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 13764
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 36
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 36 samples exceed the criterion for Nitrate as N.
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
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 Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 13750
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 36
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 36 samples exceed the criterion for Nitrate as N.
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when nitrate exceeds 30 mg/L NO3 as N in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 17675
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 435
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 435 samples exceed the criterion for Nitrate as N.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when nitrate exceeds 30 mg/L NO3 as N in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 8 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut, PC-SFL PC-DOW Casa de Fruta]
Temporal Representation: Data was collected over the time period 10/1/2002-3/13/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 127305, Nitrate
Region 3     
Pacheco Creek
 
LOE ID: 9323
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 27
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 27 samples exceed the criterion for Nitrate as N.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when nitrate exceeds 30 mg/L NO3 as N in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
 
DECISION ID
130495
Region 3     
Pacheco Creek
 
Pollutant: Nitrogen, Nitrite
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 22 samples exceed the water quality objective for the agricultural 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 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 22 samples exceed the water quality objective for the agricultural 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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 130495, Nitrogen, Nitrite
Region 3     
Pacheco Creek
 
LOE ID: 173550
 
Pollutant: Nitrogen, Nitrite
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Nitrite as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicalslisted in the Central Coast Basin Plan and identified as the maximum concentration for nitrite for livestock watering as 10 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107499
Region 3     
Pacheco 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 107499, Selenium
Region 3     
Pacheco Creek
 
LOE ID: 181390
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Selenium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107499, Selenium
Region 3     
Pacheco Creek
 
LOE ID: 180797
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Selenium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107499, Selenium
Region 3     
Pacheco Creek
 
LOE ID: 181475
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Selenium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for selenium for irrigation supply as 0.02 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107499, Selenium
Region 3     
Pacheco Creek
 
LOE ID: 181260
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Selenium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107500
Region 3     
Pacheco 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 107500, Silver
Region 3     
Pacheco Creek
 
LOE ID: 181250
 
Pollutant: Silver
LOE Subgroup: Pollutant-Water
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Silver.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107500, Silver
Region 3     
Pacheco Creek
 
LOE ID: 181930
 
Pollutant: Silver
LOE Subgroup: Pollutant-Water
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 SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Silver.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-03-02 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107501
Region 3     
Pacheco Creek
 
Pollutant: Sodium
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.

Three lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the Agricultural Supply water quality objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. None of the samples exceed the Agricultural Supply water quality objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using Table 3.2.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 107501, Sodium
Region 3     
Pacheco Creek
 
LOE ID: 181623
 
Pollutant: Sodium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Sodium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines listed in the Central Coast Basin Plan and identified as the level that severe problems may occur when sodium exceeds 69 mg/L in irrigation supply water.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2011-12-13
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107501, Sodium
Region 3     
Pacheco Creek
 
LOE ID: 9329
 
Pollutant: Sodium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 15
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Sodium.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when sodium exceeds 69 mg/L in irrigation supply water.
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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/25/2005-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107501, Sodium
Region 3     
Pacheco Creek
 
LOE ID: 181624
 
Pollutant: Sodium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 10
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 10 samples exceeded the water quality threshold for Sodium.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines listed in the Central Coast Basin Plan and identified as the level that severe problems may occur when sodium exceeds 69 mg/L in irrigation supply water.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2017-01-05 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
126350
Region 3     
Pacheco Creek
 
Pollutant: Specific Conductivity
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 six lines of evidence are available in the administrative record to assess this pollutant. Sample and exceedance counts for the lines of evidence with the fraction identified as “none” or “not recorded” are grouped together with those having the fraction “total”, based on the analytical method used. Once summed, a total of zero of 245 samples exceed the water quality objective for agricultural supply. Note that the pollutant name for the older LOEs is electrical conductivity. This was an error and the pollutant name should have always been specific conductivity. For this reason, all six of the LOEs are combined into this assessment for specific conductivity.

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 245 samples exceed the water quality objective for agricultural supply 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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 126350, Specific Conductivity
Region 3     
Pacheco Creek
 
LOE ID: 13850
 
Pollutant: Electrical Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 36
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 36 samples exceed the criterion for Conductivity(Us).
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 126350, Specific Conductivity
Region 3     
Pacheco Creek
 
LOE ID: 10222
 
Pollutant: Electrical Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Conductivity(Us).
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 126350, Specific Conductivity
Region 3     
Pacheco Creek
 
LOE ID: 10166
 
Pollutant: Electrical Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 27
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 27 samples exceed the criterion for Conductivity(Us).
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 126350, Specific Conductivity
Region 3     
Pacheco Creek
 
LOE ID: 17529
 
Pollutant: Electrical Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 157
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 157 samples exceed the criterion for Conductivity(Us).
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 4 monitoring sites [ Lover's Lane, PC-SFR - Pacheco Creek at San Felipe Rd., PC-156 - Pacheco Creek at Highway 156, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-10/30/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 126350, Specific Conductivity
Region 3     
Pacheco Creek
 
LOE ID: 182578
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for SpecificConductivity.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines listed in the Central Coast Basin Plan and identified as the level at which severe problems may occur when EC exceeds 3.0 mmho/cm in irrigation supply water (meaurements reported at 25 degrees C). EC measured, at 25 degrees C , is referred to as specific conductivity. Also note that 1 mmho/cm = 1000 uS/cm.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-31 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 126350, Specific Conductivity
Region 3     
Pacheco Creek
 
LOE ID: 182625
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for SpecificConductivity.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines listed in the Central Coast Basin Plan and identified as the level at which severe problems may occur when EC exceeds 3.0 mmho/cm in irrigation supply water (meaurements reported at 25 degrees C). EC measured, at 25 degrees C , is referred to as specific conductivity. Also note that 1 mmho/cm = 1000 uS/cm.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
126118
Region 3     
Pacheco 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 six lines of evidence are available in the administrative record to assess this pollutant. A total of 10 of 436 samples exceed the evaluation guideline (Moyle 1976) applied to protect the cold freshwater habitat 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.

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 10 of 436 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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 126118, Temperature, water
Region 3     
Pacheco Creek
 
LOE ID: 17397
 
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: 347
Number of Exceedances: 6
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 6 of 347 samples exceed the criterion for Water Temperature.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: Inland Fishes of California
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 5 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 126118, Temperature, water
Region 3     
Pacheco Creek
 
LOE ID: 14109
 
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: 36
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 36 samples exceed the criterion for Water Temperature.
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
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 Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 126118, Temperature, water
Region 3     
Pacheco Creek
 
LOE ID: 12127
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Water Temperature.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 126118, Temperature, water
Region 3     
Pacheco Creek
 
LOE ID: 12108
 
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: 28
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 3 of 28 samples exceed the criterion for Water Temperature.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 126118, Temperature, water
Region 3     
Pacheco Creek
 
LOE ID: 216933
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-31 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 126118, Temperature, water
Region 3     
Pacheco Creek
 
LOE ID: 216885
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 1 of 22 samples exceeded the water quality threshold for Temperature.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107502
Region 3     
Pacheco Creek
 
Pollutant: Total Dissolved Solids
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 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One line of evidence are available in the administrative record to assess this pollutant. This line of evidence summarizes total dissolved solids data and zero of the 22 samples exceed the water quality objective for agricultural 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. 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 22 total dissolved solids samples exceed the water quality objective for agricultural 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:
 
 
Line of Evidence (LOE) for Decision ID 107502, Total Dissolved Solids
Region 3     
Pacheco Creek
 
LOE ID: 183566
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Total Dissolved Solids.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided listed in the Central Coast Basin Plan where water quality guidelines state that severe problems may occur when EC exceeds 3.0 mmho/cm in irrigation supply water (meaurements reported at 25 degrees C). EC measured, at 25 degrees C , is referred to as specific conductivity. Also note that 1 mmho/cm = 1000 uS/cm. In footnote b of Table 3-1, the mmho/cm x 640 = approximate total dissolved solids (TDS) in mg/L or ppm. Therefore, 3.0 mmho/cm x 640 = 1920 with rounding to one significant figure equals 2,000 mg/L TDS.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107504
Region 3     
Pacheco 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 three lines of evidence are available in the administrative record to assess this pollutant. A total of zero of 22 samples exceed the water quality objective for the agricultural supply beneficial use, zero of 22 samples exceed the water quality objective for the cold freshwater habitat beneficial use and zero of 22 samples exceed the water quality objective for the warm freshwater habitat 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 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 22 samples exceed the water quality objective for the agricultural supply beneficial use, zero of 22 samples exceed the water quality objective for the cold freshwater habitat beneficial use and zero of 22 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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 107504, Zinc
Region 3     
Pacheco Creek
 
LOE ID: 156900
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Zinc.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in the Central Coast Basin Plan and identified as the maximum concentration for zinc for irrigation supply as 2.0 mg/L.
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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107504, Zinc
Region 3     
Pacheco Creek
 
LOE ID: 156921
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Zinc.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107504, Zinc
Region 3     
Pacheco Creek
 
LOE ID: 182730
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 22 samples exceeded the water quality threshold for Zinc.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-12-05
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107498
Region 3     
Pacheco 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.

Thirty-six lines of evidence is available in the administrative record to assess this pollutant. Thirty-three of the 473 samples exceed the maximum pH water quality objective for Municipal and Domestic Supply, Contact and Non-contact Recreation beneficial uses. Twenty-one of the 473 samples exceed the maximum pH water quality objectives for Cold and Warm Freshwater Habitat and 22 of 473 samples exceeded the Agriculture Supply objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Thirty-three of the 473 samples exceed the maximum pH water quality objective for Municipal and Domestic Supply, Contact and Non-contact Recreation beneficial uses, 21 of the 473 samples exceed the maximum pH water quality objectives for Cold and Warm Freshwater Habitat and 22 of 473 samples exceeded the Agriculture Supply objective 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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10240
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 17809
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 385
Number of Exceedances: 19
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 19 of 385 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 5 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10184
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 28
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 1 of 28 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 13871
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 36
Number of Exceedances: 13
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 13 of 36 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
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 Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10242
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 16912
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 385
Number of Exceedances: 12
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 12 of 385 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 5 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 14074
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 9
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 9 of 36 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
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 Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10243
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10219
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 28
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 28 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 13870
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 36
Number of Exceedances: 13
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 13 of 36 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
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 Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10183
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 28
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 1 of 28 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10241
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 17808
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 385
Number of Exceedances: 19
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 19 of 385 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 5 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 178340
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-31 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 177375
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines listed in the Central Coast Basin Plan and identified as the level that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-31 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 177192
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 21 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 179154
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 21 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 177463
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 21 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines listed in the Central Coast Basin Plan and identified as the level that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 176960
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-31 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 178377
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-31 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 178815
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-31 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 178339
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 21 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 177339
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference: Field data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-08-31 and 2011-08-31
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 176963
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 21 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 179511
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 21 samples exceeded the water quality threshold for pH.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: 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 (305PAC)
Temporal Representation: The samples were collected between the dates of 2011-01-13 and 2017-11-07
Environmental Conditions:
QAPP Information: SWAMP 2008
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 13869
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 36
Number of Exceedances: 13
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 13 of 36 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
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 Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10182
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 28
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 1 of 28 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 17807
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 385
Number of Exceedances: 19
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 19 of 385 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Municipal and Domestic Supply Objectives, Section II.A.2.a states the following: The pH value shall neither be depressed below 6.5 or raised above 8.3.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 5 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 13855
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 9
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 9 of 36 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
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 Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10239
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file3
  Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10181
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 28
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 28 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 17806
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 385
Number of Exceedances: 12
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 12 of 385 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 5 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 13854
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 36
Number of Exceedances: 10
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Central Coast Watershed Studies (R3_CCOWS) data for Pacheco Creek to determine beneficial use support and results are as follows: 10 of 36 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCoWS (Central Coast Watershed Studies) Water Quality Data
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 2 monitoring sites [ Walnut, Lover's Lane]
Temporal Representation: Data was collected over the time period 12/28/2003-3/1/2004.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Data quality is good and Standard Operating Procedures are well documented in QAPP. However, data documentation is poor and replicate samples and other quality assurance measurements are not consistently documented in this data set.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10223
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 9/7/2005-9/8/2005. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 17805
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 385
Number of Exceedances: 12
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Pacheco Creek to determine beneficial use support and results are as follows: 12 of 385 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A
  Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 5 monitoring sites [ Lover's Lane, PC-156 - Pacheco Creek at Highway 156, PC-SFR - Pacheco Creek at San Felipe Rd., PC-NFK - Pacheco Creek at North Fork, Walnut]
Temporal Representation: Data was collected over the time period 10/1/2002-1/17/2007.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107498, pH
Region 3     
Pacheco Creek
 
LOE ID: 10180
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 28
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 28 samples exceed the criterion for pH.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
 
DECISION ID
107491
Region 3     
Pacheco Creek
 
Pollutant: Chlorophyll-a
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 Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: No new data were assessed for the 2020 listing cycle.

This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. None of the 24 samples exceed the Evaluation Guideline (North Carolina Administrative code, Title 15A) and the General Water Quality Objective set to protect aquatic life beneficial uses.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. None of the 24 samples exceed the Evaluation Guideline (North Carolina Administrative code, Title 15A) and the General Water Quality Objective set to protect aquatic life beneficial uses and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using Table 3.2.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 107491, Chlorophyll-a
Region 3     
Pacheco Creek
 
LOE ID: 9325
 
Pollutant: Chlorophyll-a
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 24 samples exceed the criterion for Chlorophyll a.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
Objective/Criterion Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Objective/Criterion Reference: Water quality standards table
 
Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 2/19/1998-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 107491, Chlorophyll-a
Region 3     
Pacheco Creek
 
LOE ID: 9326
 
Pollutant: Chlorophyll-a
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 24 samples exceed the criterion for Chlorophyll a.
Data Reference: Final Data File used for assessment: CCAMP Water Quality Data_file1
  Final Data File used for assessment: CCAMP Water Quality Data_file2
  Final Data File used for assessment: CCAMP Water Quality Data_file3
 
SWAMP Data: 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 (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
Objective/Criterion Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Objective/Criterion Reference: Water quality standards table
 
Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 2/19/1998-3/15/2006. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
 
DECISION ID
81506
Region 3     
Pacheco Creek
 
Pollutant: Chlorpyrifos
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: No new data are assessed. This decision has not changed from the 2010 listing cycle.

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. Neither of the 2 samples exceed the Evaluation Guideline (Siepmann and Finlayson, 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005) applied to protect for aquatic life beneficial uses.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Neither of the 2 samples exceed the Evaluation Guideline (Seipmann and Finlayson, 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005) applied to protect for aquatic life beneficial uses 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: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 81506, Chlorpyrifos
Region 3     
Pacheco Creek
 
LOE ID: 16248
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Chlorpyrifos.
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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, 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)
Objective/Criterion Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Evaluation Guideline: One hour average maximum concentration 0.025 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 81506, Chlorpyrifos
Region 3     
Pacheco Creek
 
LOE ID: 16249
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Chlorpyrifos.
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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, 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)
Objective/Criterion Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Evaluation Guideline: One hour average maximum concentration 0.025 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
 
DECISION ID
80590
Region 3     
Pacheco Creek
 
Pollutant: Diazinon
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: No new data are assessed. This decision has not changed from the 2010 listing cycle.

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. Neither of the two samples exceed the Evaluation Guideline (Finlayson, 2004) applied to protect for aquatic life beneficial uses.

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

This conclusion is based on the staff findings that:

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

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

3. Neither of the two samples exceed the Evaluation Guideline (Finlayson, 2004) applied to protect for aquatic life beneficial uses 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: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 80590, Diazinon
Region 3     
Pacheco Creek
 
LOE ID: 16672
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Diazinon.
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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, 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)
Objective/Criterion Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Evaluation Guideline: One hour average maximum concentration 0.16 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 80590, Diazinon
Region 3     
Pacheco Creek
 
LOE ID: 16671
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Diazinon.
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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, 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)
Objective/Criterion Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Evaluation Guideline: One hour average maximum concentration 0.16 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
 
DECISION ID
83409
Region 3     
Pacheco Creek
 
Pollutant: Toxicity
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.1 and section 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Six lines of evidence are available in the administrative record to assess this pollutant in water samples. One sample can have multiple toxicity test results (or endpoints) but will be counted only once. One sample is defined as being collected on the same day at the same location. Two samples are summarized in LOEs using each of the test organisms as the pollutant name (i.e. plant toxicity, invertebrate toxicity or vertebrate toxicity). Zero of the two samples were toxic to test organisms (exhibited a significant increase in mortality or decrease in cell density compared to the laboratory control).

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

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the two samples were toxic to test organisms. Therefore, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 83409, Toxicity
Region 3     
Pacheco Creek
 
LOE ID: 24583
 
Pollutant: Plant Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Toxicity, Selenastrum capricornutum Growth (Cell Density) 4 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Significant reduction in cell count of test organism relative to the control (alpha < 0.05) and cell count <80% of control.
Guideline Reference: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83409, Toxicity
Region 3     
Pacheco Creek
 
LOE ID: 24582
 
Pollutant: Plant Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Toxicity, Selenastrum capricornutum Growth (Cell Density) 4 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Significant reduction in cell count of test organism relative to the control (alpha < 0.05) and cell count <80% of control.
Guideline Reference: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83409, Toxicity
Region 3     
Pacheco Creek
 
LOE ID: 24439
 
Pollutant: Invertebrate Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83409, Toxicity
Region 3     
Pacheco Creek
 
LOE ID: 24581
 
Pollutant: Vertebrate Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83409, Toxicity
Region 3     
Pacheco Creek
 
LOE ID: 24571
 
Pollutant: Vertebrate Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83409, Toxicity
Region 3     
Pacheco Creek
 
LOE ID: 24438
 
Pollutant: Invertebrate Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Pacheco Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
SWAMP Data: 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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Spatial Representation: Data for this line of evidence for Pacheco Creek was collected at 1 monitoring site [ 305PAC-Pacheco Creek at San Felipe Road]
Temporal Representation: Data was collected over the time period 1/12/2006-5/17/2006. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):