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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name: San Benito River
Water Body ID: CAR3053002019981207091641
Water Body Type: River & Stream
 
DECISION ID
130237
Region 3     
San Benito River
 
Pollutant: Fecal Coliform
Final Listing Decision: Delist from 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (being addressed with 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
Date TMDL Approved by USEPA: 08/03/2010
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 Consequently, the fecal coliform objective for water contact recreation is no longer applicable to this waterbody and those LOEs have been removed from this decision.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, three 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.

Nine of the 89 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.

In accordance with section 2.2 of the Policy, there is sufficient justification to place it 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.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Nine of the 89 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. The Pajaro River Fecal Coliform (including San Benito R., Llagas Cr., and Tequesquita Slough) TMDL has been approved by the USEPA on 8/3/2010.
5. 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.

This water body pollutant combination should be placed in the Being Addressed portion of the CWA 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 130237, Fecal Coliform
Region 3     
San Benito River
 
LOE ID: 10290
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 42
Number of Exceedances: 6
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 6 of 42 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 130237, Fecal Coliform
Region 3     
San Benito River
 
LOE ID: 150165
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 23
Number of Exceedances: 2
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for San Benito River to determine beneficial use support and the results are as follows: 2 of the 23 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): 305BRI
Temporal Representation: The samples were collected between the days of 2011-01-12 and 2017-12-12 .
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 130237, Fecal Coliform
Region 3     
San Benito River
 
LOE ID: 150330
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 24
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for San Benito River to determine beneficial use support and the results are as follows: 1 of the 24 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): 305SAN
Temporal Representation: The samples were collected between the days of 2011-01-12 and 2017-12-12 .
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
125846
Region 3     
San Benito River
 
Pollutant: Escherichia coli (E. coli)
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: 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 removal from the CWA section 303(d) List under section 4.3 of the Listing Policy, as applicable, using the E. coli objective.

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

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

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

Although three lines of evidence are available in the administrative record to assess this pollutant, this decision is based upon evaluation of the E. coli data collected since 2010 from monitoring stations where salinity is less than 1 ppt 95 percent of the time (see LOE 150310) which are most representative of existing conditions in the waterbody. Note, the salinity at station 305SAN (LOE 150164) is above the salinity threshold for use of the E. coli water quality objective (1.71 ppt, 95 percent of the time) and the data from this station is not used in this decision.

Thirteen of the 23 samples collected since 2010 (see LOE 150310) exceed the STV water quality objective and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. No geomeans could be calculated for these data. The data were collected between 2011 and 2017 and represent a range of hydrologic conditions (both wet and dry years). This sample count of data collected since 2010 is adequate to determine the beneficial use is not supported 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). A total of 16 of the 30 historic samples exceed the USEPA criteria set to protect for water contact recreation (see LOE 10292). 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, RWQCB staff concludes that the water body-pollutant combination should not be removed from the CWA section 303(d) List because applicable water quality standards for the pollutant are being exceeded. However, the spatial extent of the impaired segment is limited to the reach upstream of the station 305BRI, where the salinity is less than 1 ppt in 95 percent or more of the samples.

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. Thirteen of the 23 samples collected since 2010 (see LOE 150310) exceed the STV water quality objective and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) List because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation: Although three lines of evidence are available in the administrative record to assess this pollutant, this decision is based upon evaluation of the E. coli data collected since 2010 from monitoring stations where salinity is less than 1 ppt 95 percent of the time (see LOE 150310) which are most representative of existing conditions in the waterbody. Note, the salinity at station 305SAN (LOE 150164) is above the salinity threshold for use of the E. coli water quality objective (1.71 ppt, 95 percent of the time) and the data from this station is not used in this decision.

Thirteen of the 23 samples collected since 2010 (see LOE 150310) exceed the STV water quality objective and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. No geomeans could be calculated for these data. The data were collected between 2011 and 2017 and represent a range of hydrologic conditions (both wet and dry years). This sample count of data collected since 2010 is adequate to determine the beneficial use is not supported 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). A total of 16 of the 30 historic samples exceed the USEPA criteria set to protect for water contact recreation (see LOE 10292). 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, RWQCB staff concludes that the water body-pollutant combination should not be removed from the CWA section 303(d) List because applicable water quality standards for the pollutant are being exceeded. However, the spatial extent of the impaired segment is limited to the reach upstream of the station 305BRI, where the salinity is less than 1 ppt in 95 percent or more of the samples.

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. Thirteen of the 23 samples collected since 2010 (see LOE 150310) exceed the STV water quality objective and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
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 125846, Escherichia coli (E. coli)
Region 3     
San Benito River
 
LOE ID: 150310
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 23
Number of Exceedances: 13
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for San Benito River to determine beneficial use support and the results are as follows: 13 of the 23 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): 305BRI
Temporal Representation: The samples were collected between the days of 2011-01-12 and 2017-12-12 .
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 125846, Escherichia coli (E. coli)
Region 3     
San Benito River
 
LOE ID: 10292
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 30
Number of Exceedances: 16
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 16 of 30 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 1/24/2005-3/14/2006. 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 125846, Escherichia coli (E. coli)
Region 3     
San Benito River
 
LOE ID: 150164
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 23
Number of Exceedances: 8
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for San Benito River to determine beneficial use support and the results are as follows: 8 of the 23 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): 305SAN
Temporal Representation: The samples were collected between the days of 2011-01-12 and 2017-12-12 .
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
126392
Region 3     
San Benito River
 
Pollutant: Specific Conductivity
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(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 65 of 326 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 eight 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 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 65 of 326 samples exceed the water quality objective for agricultural supply 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 126392, Specific Conductivity
Region 3     
San Benito River
 
LOE ID: 182552
 
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 San Benito River 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 126392, Specific Conductivity
Region 3     
San Benito River
 
LOE ID: 182373
 
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 San Benito River 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-09-08 and 2011-09-08
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 126392, Specific Conductivity
Region 3     
San Benito River
 
LOE ID: 17510
 
Pollutant: Electrical Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 233
Number of Exceedances: 58
 
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 San Benito River to determine beneficial use support and results are as follows: 58 of 233 samples exceed the criterion for Conductivity(Us).
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 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 San Benito River was collected at 1 monitoring site [ SB-YRD - San Benito River at Y Road]
Temporal Representation: Data was collected over the time period 8/20/2001-10/30/2004.
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 126392, Specific Conductivity
Region 3     
San Benito River
 
LOE ID: 10291
 
Pollutant: Electrical Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 42
Number of Exceedances: 5
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 5 of 42 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 126392, Specific Conductivity
Region 3     
San Benito River
 
LOE ID: 11161
 
Pollutant: Electrical Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for San Benito River to determine beneficial use support and results are as follows: 1 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 8/30/2005-8/31/2005. 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 126392, Specific Conductivity
Region 3     
San Benito River
 
LOE ID: 182517
 
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 San Benito River 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 (305SAN)
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 126392, Specific Conductivity
Region 3     
San Benito River
 
LOE ID: 48943
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Water Board Staff assessed public submissions data for San Benito River to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Conductivity(Us).
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
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 3000 uS/cm in irrigation supply water.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for San Benito River was collected at 1 monitoring site [ 305SANxxx - San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/1/2008.
Environmental Conditions: Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 126392, Specific Conductivity
Region 3     
San Benito River
 
LOE ID: 182557
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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
107247
Region 3     
San Benito River
 
Pollutant: pH
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(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 section 303(d) List under sections 4.2 and 4.3 of the Listing Policy. Under these section, a single line of evidence is necessary to assess listing status.

Forty lines of evidence is available in the administrative record to assess this pollutant. Ninety-five of the 425 samples exceed the maximum pH water quality objective for Municipal and Domestic Supply, Contact and Non-contact Recreation beneficial uses. Forty-three of the 425 samples exceed the maximum pH water quality objective for Warm Freshwater Habitat and 74 of 425 samples exceeded the Agriculture Supply objective.
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.

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. Ninety-five of the 425 samples exceed the maximum pH water quality objective for Municipal and Domestic Supply, Contact and Non-contact Recreation beneficial uses, 43 of the 425 samples exceed the maximum pH water quality objective for Warm Freshwater Habitat and 74 of 425 samples exceeded the Agriculture Supply objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 48979
 
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: Central Coast Water Board Staff assessed public submissions data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for pH.
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH value shall not be depressed below 7.0 or raised above 8.5 (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for San Benito River was collected at 1 monitoring site [ 305SANxxx - San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/1/2008.
Environmental Conditions: Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 107247, pH
Region 3     
San Benito River
 
LOE ID: 179903
 
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 San Benito River 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 (305SAN)
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 177612
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for San Benito River to determine beneficial use support and results are as follows: 1 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-09-08 and 2011-09-08
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 17574
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 332
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 San Benito River to determine beneficial use support and results are as follows: 36 of 332 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 San Benito River was collected at 4 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir]
Temporal Representation: Data was collected over the time period 10/23/2001-2/11/2007.
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 11162
 
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 San Benito River 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 8/30/2005-8/31/2005. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 48961
 
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: Central Coast Water Board Staff assessed public submissions data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for pH.
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
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 Region 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 for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for San Benito River was collected at 1 monitoring site [ 305SANxxx - San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/1/2008.
Environmental Conditions: Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 107247, pH
Region 3     
San Benito River
 
LOE ID: 10309
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 43
Number of Exceedances: 15
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 15 of 43 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 48962
 
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: Central Coast Water Board Staff assessed public submissions data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for pH.
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH value shall not be depressed below 6.5 or raised above 8.3 (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for San Benito River was collected at 1 monitoring site [ 305SANxxx - San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/1/2008.
Environmental Conditions: Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 107247, pH
Region 3     
San Benito River
 
LOE ID: 11163
 
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 San Benito River 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 8/30/2005-8/31/2005. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 10310
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 43
Number of Exceedances: 17
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 17 of 43 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 17575
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 332
Number of Exceedances: 50
 
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 San Benito River to determine beneficial use support and results are as follows: 50 of 332 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 San Benito River was collected at 4 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir]
Temporal Representation: Data was collected over the time period 10/23/2001-2/11/2007.
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 17591
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 332
Number of Exceedances: 50
 
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 San Benito River to determine beneficial use support and results are as follows: 50 of 332 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 San Benito River was collected at 4 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir]
Temporal Representation: Data was collected over the time period 10/23/2001-2/11/2007.
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 11179
 
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 San Benito River 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 8/30/2005-8/31/2005. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 10312
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 43
Number of Exceedances: 17
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 17 of 43 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 48964
 
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: Central Coast Water Board Staff assessed public submissions data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for pH.
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for San Benito River was collected at 1 monitoring site [ 305SANxxx - San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/1/2008.
Environmental Conditions: Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 107247, pH
Region 3     
San Benito River
 
LOE ID: 178721
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for San Benito River to determine beneficial use support and results are as follows: 1 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-09-08 and 2011-09-08
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 17592
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 332
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 San Benito River to determine beneficial use support and results are as follows: 19 of 332 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 San Benito River was collected at 4 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir]
Temporal Representation: Data was collected over the time period 10/23/2001-2/11/2007.
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 11180
 
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 San Benito River 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 8/30/2005-8/31/2005. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 10328
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 43
Number of Exceedances: 6
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 6 of 43 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 17576
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 332
Number of Exceedances: 50
 
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 San Benito River to determine beneficial use support and results are as follows: 50 of 332 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 San Benito River was collected at 4 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir]
Temporal Representation: Data was collected over the time period 10/23/2001-2/11/2007.
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 11178
 
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 San Benito River 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 8/30/2005-8/31/2005. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 10311
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 43
Number of Exceedances: 17
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 17 of 43 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 107247, pH
Region 3     
San Benito River
 
LOE ID: 48963
 
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: Central Coast Water Board Staff assessed public submissions data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for pH.
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for San Benito River was collected at 1 monitoring site [ 305SANxxx - San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/1/2008.
Environmental Conditions: Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 107247, pH
Region 3     
San Benito River
 
LOE ID: 179131
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 23
Number of Exceedances: 8
 
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 San Benito River to determine beneficial use support and results are as follows: 8 of 23 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 178153
 
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 San Benito River 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 (305SAN)
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 178120
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for San Benito River to determine beneficial use support and results are as follows: 1 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-09-08 and 2011-09-08
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 179157
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for San Benito River to determine beneficial use support and results are as follows: 1 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-09-08 and 2011-09-08
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 178380
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 22
Number of Exceedances: 19
 
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 San Benito River to determine beneficial use support and results are as follows: 19 of 22 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 178152
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 22
Number of Exceedances: 19
 
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 San Benito River to determine beneficial use support and results are as follows: 19 of 22 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 179069
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 22
Number of Exceedances: 19
 
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 San Benito River to determine beneficial use support and results are as follows: 19 of 22 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 177533
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 23
Number of Exceedances: 8
 
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 San Benito River to determine beneficial use support and results are as follows: 8 of 23 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 178216
 
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 San Benito River 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 (305SAN)
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 177376
 
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 San Benito River 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 (305SAN)
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 178689
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 23
Number of Exceedances: 6
 
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 San Benito River to determine beneficial use support and results are as follows: 6 of 23 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 178666
 
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 San Benito River 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 (305SAN)
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 178215
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 23
Number of Exceedances: 8
 
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 San Benito River to determine beneficial use support and results are as follows: 8 of 23 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 177084
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for San Benito River to determine beneficial use support and results are as follows: 1 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-09-08 and 2011-09-08
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 177096
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 23
Number of Exceedances: 4
 
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 San Benito River to determine beneficial use support and results are as follows: 4 of 23 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 177880
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 22
Number of Exceedances: 16
 
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 San Benito River to determine beneficial use support and results are as follows: 16 of 22 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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 107247, pH
Region 3     
San Benito River
 
LOE ID: 177238
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
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 San Benito River to determine beneficial use support and results are as follows: 13 of 22 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-11-14
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
127257
Region 3     
San Benito River
 
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.

Eight 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 68 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 511 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 127257, Ammonia
Region 3     
San Benito River
 
LOE ID: 183775
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 23
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 San Benito River to determine beneficial use support and results are as follows: 0 of 23 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 127257, Ammonia
Region 3     
San Benito River
 
LOE ID: 184080
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 12 samples exceeded the water quality threshold for Ammonia as N. Although a total of 15 samples were collected, 3 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: 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 (305BRI).
Temporal Representation: Data for this waterbody was collected over the date range 2011-02-09 to 2017-11-14
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 127257, Ammonia
Region 3     
San Benito River
 
LOE ID: 184088
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 24
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 San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 127257, Ammonia
Region 3     
San Benito River
 
LOE ID: 219504
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 11
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and the results are as follows: 0 of the 11 samples exceeded the water quality threshold for Ammonia as N, Unionized. Although a total of 21 samples were collected, 10 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 (305BRI).
Temporal Representation: Data for this waterbody was collected over the date range 2011-01-12 to 2017-11-14
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 127257, Ammonia
Region 3     
San Benito River
 
LOE ID: 219598
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 15
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 15 samples exceeded the water quality threshold for Ammonia as N, Unionized. Although a total of 22 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: 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 (305SAN).
Temporal Representation: Data for this waterbody was collected over the date range 2011-01-12 to 2017-11-14
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 127257, Ammonia
Region 3     
San Benito River
 
LOE ID: 17814
 
Pollutant: Ammonia as Nitrogen
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 422
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 San Benito River to determine beneficial use support and results are as follows: 0 of 422 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 San Benito River was collected at 5 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir, SB-AHR]
Temporal Representation: Data was collected over the time period 8/20/2001-3/13/2007.
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 127257, Ammonia
Region 3     
San Benito River
 
LOE ID: 9261
 
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: 42
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 San Benito River to determine beneficial use support and results are as follows: 0 of 42 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 127257, Ammonia
Region 3     
San Benito River
 
LOE ID: 9260
 
Pollutant: Ammonia as Nitrogen
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 42
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 San Benito River to determine beneficial use support and results are as follows: 0 of 42 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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
107230
Region 3     
San Benito River
 
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 four lines of evidence are available in the administrative record to assess this pollutant. A total of zero of eight samples exceed the water quality objective for the agricultural supply beneficial use and zero of eight 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 eight samples exceed the water quality objective for the agricultural supply beneficial use and zero of eight 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 107230, Arsenic
Region 3     
San Benito River
 
LOE ID: 158024
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107230, Arsenic
Region 3     
San Benito River
 
LOE ID: 158092
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107230, Arsenic
Region 3     
San Benito River
 
LOE ID: 158091
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107230, Arsenic
Region 3     
San Benito River
 
LOE ID: 158447
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
107239
Region 3     
San Benito River
 
Pollutant: Azinphos-methyl (Guthion)
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 107239, Azinphos-methyl (Guthion)
Region 3     
San Benito River
 
LOE ID: 158717
 
Pollutant: Azinphos-methyl (Guthion)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The Criterion Continuous Concentration for freshwater aquatic life is 0.01 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 (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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
131898
Region 3     
San Benito River
 
Pollutant: Benthic Community Effects
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects.

Three line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. One of three benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. However, a minimum of two benthic-macroinvertebrate samples are needed to assess listing status.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of three benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. The available information is insufficient to determine whether the waterbody/pollutant combination should be placed on the 303(d) List of impaired waters at this time.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 131898, Benthic Community Effects
Region 3     
San Benito River
 
LOE ID: 232607
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 305SBACIE to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.310089776 to 0.310089776.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2020 Integrated Report for Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 3 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 305SBACIE.
Temporal Representation: Samples were collected from 5/1/2013 to 5/1/2013.
Environmental Conditions:
QAPP Information: Data collected following SWAMP QA protocols.
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 131898, Benthic Community Effects
Region 3     
San Benito River
 
LOE ID: 232609
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 305SBAHER to determine beneficial use support and the results are as follows: 0 of 1 samples exceeded the threshold. CSCI scores were from 0.857609693 to 0.857609693.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2020 Integrated Report for Region 3.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 3 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 305SBAHER.
Temporal Representation: Samples were collected from 5/1/2013 to 5/1/2013.
Environmental Conditions:
QAPP Information: Data collected following SWAMP QA protocols.
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 131898, Benthic Community Effects
Region 3     
San Benito River
 
LOE ID: 232667
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 305BRI to determine beneficial use support and the results are as follows: 0 of 1 samples exceeded the threshold. CSCI scores were from 0.817575926 to 0.817575926.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2020 Integrated Report for 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. Region 3 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 305BRI.
Temporal Representation: Samples were collected from 6/7/2011 to 6/7/2011.
Environmental Conditions:
QAPP Information: Data collected following SWAMP QA protocols.
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
 
 
DECISION ID
107257
Region 3     
San Benito River
 
Pollutant: Bifenthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107257, Bifenthrin
Region 3     
San Benito River
 
LOE ID: 151666
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin .
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin from Amweg et al. (2005) and Amweg and Weston (2007).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 305SAN.
Temporal Representation: Data for this waterbody were collected over the date range 2011-05-24 to 2011-05-24
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
107231
Region 3     
San Benito River
 
Pollutant: Cadmium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107231, Cadmium
Region 3     
San Benito River
 
LOE ID: 160163
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107231, Cadmium
Region 3     
San Benito River
 
LOE ID: 160012
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107231, Cadmium
Region 3     
San Benito River
 
LOE ID: 159703
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107231, Cadmium
Region 3     
San Benito River
 
LOE ID: 159772
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107231, Cadmium
Region 3     
San Benito River
 
LOE ID: 159257
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107231, Cadmium
Region 3     
San Benito River
 
LOE ID: 160392
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
107264
Region 3     
San Benito River
 
Pollutant: Carbophenothion
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 107264, Carbophenothion
Region 3     
San Benito River
 
LOE ID: 160404
 
Pollutant: Carbophenothion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Carbophenothion.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Drinking water notification levels are published by the Division of Drinking Water and are for chemicals for which there is no drinking water MCL. If a notification level is exceeded, local government notification is required and customer notification is recommended. The criteria for Carbophenothion (Trithion) is 0.007 mg/L.
Guideline Reference: CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107233
Region 3     
San Benito River
 
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)(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. For lines of evidence where the fraction is none staff assumed that the fraction is total, based on the analytical method, and the sample and exceedance counts are summed for both fractions for the purpose of making this decision.

Zero of three samples exceed the evaluation guideline applied to protect aquatic life beneficial uses. One line of evidence reports zero of zero samples exceeding the evaluation guideline because these samples have laboratory data reporting limit(s) 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. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.


After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List because applicable water quality standards are not being exceeded.


This conclusion is based on the staff findings that:

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

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

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

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: 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 107233, Chlorpyrifos
Region 3     
San Benito River
 
LOE ID: 16347
 
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 San Benito River 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 1/10/2006-5/17/2006. 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 107233, Chlorpyrifos
Region 3     
San Benito River
 
LOE ID: 16280
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 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 San Benito River to determine beneficial use support and results are as follows: 0 of 1 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/3/2006. 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 107233, Chlorpyrifos
Region 3     
San Benito River
 
LOE ID: 161927
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: 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 freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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
107271
Region 3     
San Benito River
 
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 eight samples exceed the water quality objective for the agricultural supply beneficial use and zero of eight samples exceed the water quality objective 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.

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 eight samples exceed the water quality objective for the agricultural supply beneficial use and zero of eight samples exceed the water quality objective 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:
 
 
Line of Evidence (LOE) for Decision ID 107271, Chromium
Region 3     
San Benito River
 
LOE ID: 162282
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107271, Chromium
Region 3     
San Benito River
 
LOE ID: 162157
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107271, Chromium
Region 3     
San Benito River
 
LOE ID: 162133
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107271, Chromium
Region 3     
San Benito River
 
LOE ID: 162156
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
107276
Region 3     
San Benito River
 
Pollutant: Coumaphos
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 107276, Coumaphos
Region 3     
San Benito River
 
LOE ID: 163340
 
Pollutant: Coumaphos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.037 ug/L for invertabretes (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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
107268
Region 3     
San Benito River
 
Pollutant: Cyfluthrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107268, Cyfluthrin
Region 3     
San Benito River
 
LOE ID: 152325
 
Pollutant: Cyfluthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total .
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 305SAN.
Temporal Representation: Data for this waterbody were collected over the date range 2011-05-24 to 2011-05-24
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
107270
Region 3     
San Benito River
 
Pollutant: Cyhalothrin, Lambda
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107270, Cyhalothrin, Lambda
Region 3     
San Benito River
 
LOE ID: 152460
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- .
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 305SAN.
Temporal Representation: Data for this waterbody were collected over the date range 2011-05-24 to 2011-05-24
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
107258
Region 3     
San Benito River
 
Pollutant: Cypermethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107258, Cypermethrin
Region 3     
San Benito River
 
LOE ID: 152929
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total .
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al. (2002).
Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 305SAN.
Temporal Representation: Data for this waterbody were collected over the date range 2011-05-24 to 2011-05-24
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
107269
Region 3     
San Benito River
 
Pollutant: Deltamethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 107269, Deltamethrin
Region 3     
San Benito River
 
LOE ID: 153562
 
Pollutant: Deltamethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin .
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 305SAN.
Temporal Representation: Data for this waterbody were collected over the date range 2011-05-24 to 2011-05-24
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
107235
Region 3     
San Benito River
 
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)(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 sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of five water samples exceed the aquatic life evaluation guideline (Finlayson, 2004). This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported using table 3.1.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List because applicable water quality standards are not being exceeded.

This conclusion is based on the staff findings that:

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

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

3. Zero samples exceeded the water quality objectives. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 107235, Diazinon
Region 3     
San Benito River
 
LOE ID: 164149
 
Pollutant: Diazinon
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Diazinon.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).
Guideline Reference: Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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 107235, Diazinon
Region 3     
San Benito River
 
LOE ID: 16703
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.
Data Reference: Final Data File used for assessment: SWAMP Toxicity Data 2001-06
 
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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/3/2006. 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 107235, Diazinon
Region 3     
San Benito River
 
LOE ID: 16770
 
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 San Benito River 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 1/10/2006-5/17/2006. 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
107236
Region 3     
San Benito River
 
Pollutant: Dichlorvos
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1, and single line of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of zero water samples exceed the evaluation guideline applied to protect aquatic life beneficial uses. In this case, some samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Zero of 2 water samples exceed the drinking water advisory level for municipal and domestic water supply. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported using table 3.1.

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

This conclusion is based on the staff findings that:

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

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

3. Zero samples exceed the evaluation guidelines. 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 107236, Dichlorvos
Region 3     
San Benito River
 
LOE ID: 164456
 
Pollutant: Dichlorvos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: 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, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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 107236, Dichlorvos
Region 3     
San Benito River
 
LOE ID: 164214
 
Pollutant: Dichlorvos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Dichlorvos.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA IRIS one-in-a-million cancer risk estimate from oral exposure for dichlorvos is 0.1 ug/L.
Guideline Reference: IRIS Database Calculations (summary)
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107263
Region 3     
San Benito River
 
Pollutant: Dicrotophos
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 107263, Dicrotophos
Region 3     
San Benito River
 
LOE ID: 164284
 
Pollutant: Dicrotophos
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Dicrotophos.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Dicrophos is the USEPA Aquatic Life Benchmark of 1.7 ug/L for invertebrates (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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 107263, Dicrotophos
Region 3     
San Benito River
 
LOE ID: 164245
 
Pollutant: Dicrotophos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Dicrotophos.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA expected safe lifetime exposure limit in drinking water for Dicrotophos calculated using the IRIS Reference Dose, is 0.7 ug/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, 20% relative source contribution from drinking water, and 0.0001 mg/kg/day as the reference dose.
Guideline Reference: IRIS Reference Summary (Various Pollutants)
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107260
Region 3     
San Benito River
 
Pollutant: Dimethoate
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 sections 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of two water samples exceeded the USEPA aquatic life evaluation guideline. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported using table 3.1.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List because applicable water quality standards are not being exceeded.

This conclusion is based on the staff findings that:

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

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

3. Zero samples exceed the evaluation guidelines. 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 107260, Dimethoate
Region 3     
San Benito River
 
LOE ID: 164608
 
Pollutant: Dimethoate
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Dimethoate.
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, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107237
Region 3     
San Benito River
 
Pollutant: Disulfoton
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 107237, Disulfoton
Region 3     
San Benito River
 
LOE ID: 165226
 
Pollutant: Disulfoton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Disulfoton.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA drinking water health advisory for disulfoton is 0.7 ug/L.
Guideline Reference: 2018 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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 107237, Disulfoton
Region 3     
San Benito River
 
LOE ID: 165163
 
Pollutant: Disulfoton
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Disulfoton. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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
107238
Region 3     
San Benito River
 
Pollutant: Dyfonate (Fonofos or Fonophos)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107238, Dyfonate (Fonofos or Fonophos)
Region 3     
San Benito River
 
LOE ID: 166842
 
Pollutant: Dyfonate (Fonofos or Fonophos)
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Fonofos.
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, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fonofos is the maximum acceptable toxicant concentration (MATC) of 0.45 ug/L. The MATC is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 0.64 ug/L and the no observed effect concentration (NOEC) of 0.31 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107273
Region 3     
San Benito River
 
Pollutant: Esfenvalerate/Fenvalerate
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 107273, Esfenvalerate/Fenvalerate
Region 3     
San Benito River
 
LOE ID: 154112
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total .
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 305SAN.
Temporal Representation: Data for this waterbody were collected over the date range 2011-05-24 to 2011-05-24
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
107256
Region 3     
San Benito River
 
Pollutant: Ethion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107256, Ethion
Region 3     
San Benito River
 
LOE ID: 165893
 
Pollutant: Ethion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ethion.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA expected safe lifetime exposure limit in drinking water for Ethion, calculated using the IRIS Reference Dose, is 3.5 ug/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, 20% relative source contribution from drinking water, and 0.0005 mg/kg/day as the reference dose.
Guideline Reference: IRIS Reference Summary (Various Pollutants)
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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 107256, Ethion
Region 3     
San Benito River
 
LOE ID: 165629
 
Pollutant: Ethion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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
107261
Region 3     
San Benito River
 
Pollutant: Ethoprop
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the Clean Water Act (CWA) section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

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

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. A total of zero of two samples exceed the evaluation guideline for the warm freshwater habitat beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 107261, Ethoprop
Region 3     
San Benito River
 
LOE ID: 166124
 
Pollutant: Ethoprop
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ethoprop.
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, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107265
Region 3     
San Benito River
 
Pollutant: Fenitrothion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107265, Fenitrothion
Region 3     
San Benito River
 
LOE ID: 166014
 
Pollutant: Fenitrothion
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Fenitrothion.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fenitrothion is the USEPA Aquatic Life Benchmark of 0.087 ug/L for an invertebrate (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107272
Region 3     
San Benito River
 
Pollutant: Fenpropathrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 107272, Fenpropathrin
Region 3     
San Benito River
 
LOE ID: 154001
 
Pollutant: Fenpropathrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fenpropathrin .
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for fenpropathrin is the median lethal concentration (LC50) of 1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1 ug/g is the geometric mean of LC50 values for fenpropathrin from Ding et al. ( 2011).
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 305SAN.
Temporal Representation: Data for this waterbody were collected over the date range 2011-05-24 to 2011-05-24
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
107266
Region 3     
San Benito River
 
Pollutant: Fenthion
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 107266, Fenthion
Region 3     
San Benito River
 
LOE ID: 166408
 
Pollutant: Fenthion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenthion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Fenthion is the USEPA Aquatic Life Benchmark of 0.013 ug/L for an invertebrate (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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
107241
Region 3     
San Benito River
 
Pollutant: Malathion
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of zero samples exceed the evaluation guideline (Faria et al., 2010) applied to protect aquatic life beneficial uses. In this case, some samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Zero of two samples exceed the evaluation guideline for drinking water (USEPA drinking water health advisory). These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List because applicable water quality standards are not being exceeded.

This conclusion is based on the staff findings that:

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

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

3. Zero samples exceeded the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

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 107241, Malathion
Region 3     
San Benito River
 
LOE ID: 169056
 
Pollutant: Malathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Aquatic life should not be affected unacceptably if the four-day average concentration of malathion does not exceed 0.028 ug/L more than once every three years on the average (Faria et al., 2010).
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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 107241, Malathion
Region 3     
San Benito River
 
LOE ID: 168761
 
Pollutant: Malathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Malathion.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA drinking water health advisory for malathion is 500 ug/L.
Guideline Reference: 2018 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
130759
Region 3     
San Benito River
 
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.

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

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

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of eight water samples exceeded the evaluation guidelines for aquatic life and agricultural supply beneficial uses. One of eight water samples exceed the evaluation guidelines for commercial and municipal beneficial. 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 130759, Mercury
Region 3     
San Benito River
 
LOE ID: 169307
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 130759, Mercury
Region 3     
San Benito River
 
LOE ID: 169165
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 130759, Mercury
Region 3     
San Benito River
 
LOE ID: 169377
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 130759, Mercury
Region 3     
San Benito River
 
LOE ID: 169177
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 4
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 San Benito River to determine beneficial use support and results are as follows: 1 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 130759, Mercury
Region 3     
San Benito River
 
LOE ID: 169472
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 130759, Mercury
Region 3     
San Benito River
 
LOE ID: 168803
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
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 San Benito River to determine beneficial use support and results are as follows: 1 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 130759, Mercury
Region 3     
San Benito River
 
LOE ID: 169342
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 130759, Mercury
Region 3     
San Benito River
 
LOE ID: 169311
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
107259
Region 3     
San Benito River
 
Pollutant: Methidathion
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 sections 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of two water samples exceeded the USEPA aquatic life evaluation guideline. Zero of two water samples exceed the USEPA drinking water health advisory level for municipal and domestic water supply. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported using table 3.1.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List because applicable water quality standards are not being exceeded.

This conclusion is based on the staff findings that:

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

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

3. Zero samples exceed the evaluation guidelines. 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 107259, Methidathion
Region 3     
San Benito River
 
LOE ID: 169614
 
Pollutant: Methidathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Methidathion.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for methidathion is 0.7 ug/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, and 20% relative source contribution from drinking water. An additional uncertainty factor of 10 is used for Class C carcinogens.
Guideline Reference: IRIS Database Calculations (summary)
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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 107259, Methidathion
Region 3     
San Benito River
 
LOE ID: 169630
 
Pollutant: Methidathion
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Methidathion.
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, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107243
Region 3     
San Benito River
 
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 eight lines of evidence are available in the administrative record to assess this pollutant. A total of zero of eight samples exceed the water quality objective for the agricultural supply beneficial use, zero of eight samples exceed the water quality objective for the commercial or recreational collection of fish, shellfish, or organisms beneficial use, zero of eight samples exceed the evaluation guideline for the municipal and domestic supply beneficial use and zero of eight 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 eight samples exceed the water quality objective for the agricultural supply beneficial use, zero of eight samples exceed the water quality objective for the commercial or recreational collection of fish, shellfish, or organisms beneficial use, zero of eight samples exceed the evaluation guideline for the municipal and domestic supply beneficial use and zero of eight 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 107243, Nickel
Region 3     
San Benito River
 
LOE ID: 171072
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107243, Nickel
Region 3     
San Benito River
 
LOE ID: 170956
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107243, Nickel
Region 3     
San Benito River
 
LOE ID: 170744
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107243, Nickel
Region 3     
San Benito River
 
LOE ID: 171373
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107243, Nickel
Region 3     
San Benito River
 
LOE ID: 171003
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107243, Nickel
Region 3     
San Benito River
 
LOE ID: 170922
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107243, Nickel
Region 3     
San Benito River
 
LOE ID: 171033
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107243, Nickel
Region 3     
San Benito River
 
LOE ID: 171283
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
128111
Region 3     
San Benito River
 
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.

Sixteen 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 (same pollutant). 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.

The Agricultural Supply beneficial use is fully supported. One of the 512 nitrate samples and zero of the 23 nitrate/nitrite samples exceed this water quality objective.

The Municipal and Domestic Supply beneficial use is fully supported. Two of the 512 nitrate samples and zero of the 23 nitrate/nitrite samples exceed this water quality objective.

There is insufficient information available to make a use support determination for Aquatic Life beneficial uses. Although nine of the 47 nitrate 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 insufficient supporting data, such as dissolved oxygen or chlorophyll a measurements, to justify 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 section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Two of the 512 nitrate and zero of the 23 nitrate/nitrite samples exceed the Municipal & Domestic Supply water quality objective and one of the 512 nitrate samples and zero of the 23 nitrate/nitrite samples 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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 172270
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 23
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 San Benito River to determine beneficial use support and results are as follows: 0 of 23 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 172133
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 23
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 San Benito River to determine beneficial use support and results are as follows: 0 of 23 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 17693
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 423
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for San Benito River to determine beneficial use support and results are as follows: 1 of 423 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 San Benito River was collected at 5 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir, SB-AHR]
Temporal Representation: Data was collected over the time period 8/20/2001-3/13/2007.
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 17707
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 423
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for San Benito River to determine beneficial use support and results are as follows: 2 of 423 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 San Benito River was collected at 5 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir, SB-AHR]
Temporal Representation: Data was collected over the time period 8/20/2001-3/13/2007.
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 9263
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 42
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 San Benito River to determine beneficial use support and results are as follows: 0 of 42 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 9264
 
Pollutant: Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 42
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 San Benito River to determine beneficial use support and results are as follows: 0 of 42 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 171687
 
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 San Benito River 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2011-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 172290
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 23
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 San Benito River to determine beneficial use support and results are as follows: 0 of 23 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 172120
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 172003
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 24
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 San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 172591
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 24
Number of Exceedances: 9
 
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 San Benito River to determine beneficial use support and results are as follows: 9 of 24 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 171512
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 11
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 11 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2011-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 171429
 
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 San Benito River 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2011-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 171664
 
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 San Benito River 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2011-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 171440
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 11
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 San Benito River to determine beneficial use support and results are as follows: 0 of 11 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2011-12-12
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 128111, Nitrate
Region 3     
San Benito River
 
LOE ID: 171515
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 11
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 San Benito River to determine beneficial use support and results are as follows: 0 of 11 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2011-12-12
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
130635
Region 3     
San Benito River
 
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 two lines of evidence are available in the administrative record to assess this pollutant. A total of zero of 47 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 47 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 130635, Nitrogen, Nitrite
Region 3     
San Benito River
 
LOE ID: 173286
 
Pollutant: Nitrogen, Nitrite
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 23
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 San Benito River to determine beneficial use support and results are as follows: 0 of 23 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 130635, Nitrogen, Nitrite
Region 3     
San Benito River
 
LOE ID: 173268
 
Pollutant: Nitrogen, Nitrite
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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
107245
Region 3     
San Benito River
 
Pollutant: Organophosphate Pesticides
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

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

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of two water samples exceeded the evaluation guideline, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 107245, Organophosphate Pesticides
Region 3     
San Benito River
 
LOE ID: 173254
 
Pollutant: Organophosphate Pesticides
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Organophosphorus Pesticides.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for the protection of aquatic life from the additive effects of the organophophate pesticides chlorpyrifos and diazinon is one toxic unit equivalent. A toxic unit equivalent is equal to the sum of chlorpyrifos and diazinon from a single sample, each having their reported concentration divided their respective evaluation guideline prior to being summed. If this results in a value greater than one, the sample is considered to be in exceedance of the water quality standard. (Bailey et al., 1997).
Guideline Reference: Joint acute toxicity of Diazinon and Chlorpyrifos to Ceriodaphnia dubia.
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107246
Region 3     
San Benito River
 
Pollutant: Oxygen, Dissolved
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

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

Three of 53 samples exceed the water quality objective for fish spawning (Basin Plan). Forty-one of 383 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 placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. The data support the conclusion that the aquatic life beneficial use is fully supported.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Three of 53 samples exceed the objective for fish spawning and 43 of 383 samples exceed the objective for warm freshwater habitat. These do not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List 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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 174945
 
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 San Benito River 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 (305SAN)
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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 174946
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 25
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 San Benito River to determine beneficial use support and results are as follows: 0 of 25 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 175296
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial 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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 48959
 
Pollutant: Oxygen, Dissolved
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: Central Coast Water Board Staff assessed public submissions data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for San Benito River was collected at 1 monitoring site [ 305SANxxx - San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/1/2008.
Environmental Conditions: Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 175270
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Fish Spawning
 
Number of Samples: 25
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 San Benito River to determine beneficial use support and results are as follows: 1 of 25 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 174755
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Fish Spawning
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Dissolved Oxygen Study data for San Benito River to determine beneficial use support and results are as follows: 2 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 (305SAN)
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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 175101
 
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 San Benito River 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-09-07 and 2011-09-08
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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 174922
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Fish Spawning
 
Number of Samples: 24
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 San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 174754
 
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 San Benito River 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-09-07 and 2011-09-08
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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 12267
 
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: 46
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 San Benito River to determine beneficial use support and results are as follows: 0 of 46 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 11885
 
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: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for San Benito River to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: Final Data File used for assessment: 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 8/30/2005-8/31/2005. 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 107246, Oxygen, Dissolved
Region 3     
San Benito River
 
LOE ID: 17858
 
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: 281
Number of Exceedances: 40
 
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 San Benito River to determine beneficial use support and results are as follows: 40 of 281 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 San Benito River was collected at 4 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir]
Temporal Representation: Data was collected over the time period 11/21/2001-2/11/2007.
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
107275
Region 3     
San Benito River
 
Pollutant: Permethrin
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107275, Permethrin
Region 3     
San Benito River
 
LOE ID: 155507
 
Pollutant: Permethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, Total .
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin from Amweg et al. (2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 305SAN.
Temporal Representation: Data for this waterbody were collected over the date range 2011-05-24 to 2011-05-24
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
107262
Region 3     
San Benito River
 
Pollutant: Phorate
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 sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of two water samples exceeded the USEPA aquatic life evaluation guideline. Zero of two water samples exceed the National Academy of Sciences drinking water health advisory for municipal and domestic water supply. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported using table 3.1.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List because applicable water quality standards are not being exceeded.

This conclusion is based on the staff findings that:

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

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

3. Zero samples exceed the evaluation guidelines. 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 107262, Phorate
Region 3     
San Benito River
 
LOE ID: 180332
 
Pollutant: Phorate
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Phorate.
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, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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 107262, Phorate
Region 3     
San Benito River
 
LOE ID: 180370
 
Pollutant: Phorate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Phorate.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The National Academy of Sciences health advisory for phorate is 0.7 ug/L. This was calculated using the no-adverse-effect dosage of 0.01 mg/kg, assuming 70 kg body weight, 2 liters/day water consumption, 20% relative source contribution from drinking water, and divided by 100 for a factor of safety.
Guideline Reference: National Academy of Sciences - Volume I Drinking Water and Health
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107267
Region 3     
San Benito River
 
Pollutant: Phosmet
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 sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of two water samples exceed the USEPA aquatic life evaluation guideline. Zero of two samples exceed the USEPA drinking water health advisory. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported using table 3.1.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List because applicable water quality standards are not being exceeded.

This conclusion is based on the staff findings that:

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

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

3. Zero samples exceed the evaluation guidelines. 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 107267, Phosmet
Region 3     
San Benito River
 
LOE ID: 180178
 
Pollutant: Phosmet
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 Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Phosmet.
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, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Phosmet is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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 107267, Phosmet
Region 3     
San Benito River
 
LOE ID: 180481
 
Pollutant: Phosmet
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Phosmet.
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 that are toxic to, or that 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: Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for phosmet is 140 ug/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, and 20% relative source contribution from drinking water. An additional uncertainty factor of 10 is used for Class C carcinogens.
Guideline Reference: IRIS Reference Summary (Various Pollutants)
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107255
Region 3     
San Benito River
 
Pollutant: Pyrethroids
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 107255, Pyrethroids
Region 3     
San Benito River
 
LOE ID: 155640
 
Pollutant: Pyrethroids
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
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 San Benito River to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
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, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit equivalent. A toxic unit equivalent is equal to the sum of; Bifenthrin, Cyfluthrin, Cypermethrin, Lambda-Cyhalothrin, and Permethrin, each having their reported concentration divided their respective evaluation guideline prior to being summed. If this results in a value greater than one, the sample day is considered to be in exceedance of the water quality standard. (Department of Fish and Game Aquatic Life Criteria for Pyrethroid Insecticides, 2000)
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Guideline Reference: Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 305SAN.
Temporal Representation: Data for this waterbody were collected over the date range 2011-05-24 to 2011-05-24
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
107248
Region 3     
San Benito River
 
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 107248, Selenium
Region 3     
San Benito River
 
LOE ID: 181062
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107248, Selenium
Region 3     
San Benito River
 
LOE ID: 180898
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107248, Selenium
Region 3     
San Benito River
 
LOE ID: 181560
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107248, Selenium
Region 3     
San Benito River
 
LOE ID: 181417
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107248, Selenium
Region 3     
San Benito River
 
LOE ID: 180796
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107248, Selenium
Region 3     
San Benito River
 
LOE ID: 181080
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
107249
Region 3     
San Benito River
 
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 107249, Silver
Region 3     
San Benito River
 
LOE ID: 181855
 
Pollutant: Silver
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107249, Silver
Region 3     
San Benito River
 
LOE ID: 181951
 
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 San Benito River 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
107250
Region 3     
San Benito River
 
Pollutant: Terbufos
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 107250, Terbufos
Region 3     
San Benito River
 
LOE ID: 156523
 
Pollutant: Terbufos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Terbufos. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: 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, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The evaluation guideline for Terbufos is the USEPA Aquatic Life Benchmark of 0.03 ug/L for a invertebrate (acute).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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 107250, Terbufos
Region 3     
San Benito River
 
LOE ID: 156562
 
Pollutant: Terbufos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Terbufos.
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 that are toxic to, or that 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 USEPA drinking water health advisory for terbufos is 0.4 ug/L.
Guideline Reference: 2018 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107252
Region 3     
San Benito River
 
Pollutant: Trichlorfon
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 107252, Trichlorfon
Region 3     
San Benito River
 
LOE ID: 183379
 
Pollutant: Trichlorfon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Trichlorfon. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: 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 that are toxic to, or that 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 evaluation guideline for Trichlorofon is the USEPA Aquatic Life Benchmark of 0.0057 ug/L for an invertebrate (chronic).
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN).
Temporal Representation: Date for this waterbody was collected over the date range 2011-02-24 to 2011-09-21
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 107252, Trichlorfon
Region 3     
San Benito River
 
LOE ID: 183422
 
Pollutant: Trichlorfon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Trichlorfon.
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 that are toxic to, or that 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 acceptable daily intake for Trichlorfon is 26 ug/l. This was calculated for a child assuming 10 kg body weight, 1 liter/day water consumption, 20% relative source contribution from drinking water, and 1.25 mg/kg/day as the reference dose. (National Academy of Sciences Drinking Water and Health, Volume 6, 1986)
Guideline Reference: National Academy of Sciences Health Advisories document 1986
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21
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
107254
Region 3     
San Benito River
 
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 four lines of evidence are available in the administrative record to assess this pollutant. A total of zero of 47 samples exceed the water quality objective for the agricultural supply beneficial use and three of 47 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 47 samples exceed the water quality objective for the agricultural supply beneficial use and three of 47 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 107254, Zinc
Region 3     
San Benito River
 
LOE ID: 156843
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 23
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 San Benito River to determine beneficial use support and results are as follows: 2 of 23 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107254, Zinc
Region 3     
San Benito River
 
LOE ID: 156946
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 24
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 San Benito River to determine beneficial use support and results are as follows: 1 of 24 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107254, Zinc
Region 3     
San Benito River
 
LOE ID: 182831
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107254, Zinc
Region 3     
San Benito River
 
LOE ID: 182873
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 23
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 San Benito River to determine beneficial use support and results are as follows: 0 of 23 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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
107274
Region 3     
San Benito River
 
Pollutant: Aluminum
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: No Source Analysis Available
Expected TMDL Completion Date: 2035
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) List under section 3.1 of the Listing Policy.

Eight lines of evidence are available in the administrative record to assess this pollutant. Two of 7 water samples exceed the evaluation guideline applied to protect commercial or recreational collection of fish, shellfish, or organisms beneficial use(s), zero of 7 water samples exceed the evaluation guideline applied to protect the agricultural supply beneficial use (AGR) and these exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Two of 7 water samples exceed the evaluation guideline applied to protect commercial or recreational collection of fish, shellfish, or organisms beneficial use(s), zero of 7 water samples exceed the evaluation guideline applied to protect the agricultural supply beneficial use (AGR) and these exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 107274, Aluminum
Region 3     
San Benito River
 
LOE ID: 157266
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
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 San Benito River to determine beneficial use support and results are as follows: 1 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107274, Aluminum
Region 3     
San Benito River
 
LOE ID: 157227
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 4
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 San Benito River to determine beneficial use support and results are as follows: 3 of 4 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 4-day average for fish and water consumption is 0.087 mg/L (USEPA National Recommended Water Quality Criteria).
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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107274, Aluminum
Region 3     
San Benito River
 
LOE ID: 156988
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
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 San Benito River to determine beneficial use support and results are as follows: 1 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107274, Aluminum
Region 3     
San Benito River
 
LOE ID: 157156
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 4
Number of Exceedances: 4
 
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 San Benito River to determine beneficial use support and results are as follows: 4 of 4 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 4-day average for fish and water consumption is 0.087 mg/L (USEPA National Recommended Water Quality Criteria).
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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
107234
Region 3     
San Benito River
 
Pollutant: Copper
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: No Source Analysis Available
Expected TMDL Completion Date: 2035
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the 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 six lines of evidence are available in the administrative record to assess this pollutant. A total of one of 47 samples exceed the water quality objective for the agricultural supply beneficial use, zero of 47 samples exceed the water quality objective for the municipal and domestic supply beneficial use and four of 24 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 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 one of 47 samples exceed the water quality objective for the agricultural supply beneficial use, zero of 47 samples exceed the water quality objective for the municipal and domestic supply beneficial use and four of 24 samples exceed the water quality objective for the warm freshwater habitat beneficial use. This exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 107234, Copper
Region 3     
San Benito River
 
LOE ID: 162841
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 23
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 San Benito River to determine beneficial use support and results are as follows: 1 of 23 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107234, Copper
Region 3     
San Benito River
 
LOE ID: 163004
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
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 San Benito River to determine beneficial use support and the results are as follows: 2 of the 12 samples exceeded the water quality threshold for Copper. Although a total of 23 samples were collected, 11 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 (305BRI).
Temporal Representation: Data for this waterbody was collected over the date range 2011-01-12 to 2017-12-12
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 107234, Copper
Region 3     
San Benito River
 
LOE ID: 162637
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 24
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 San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107234, Copper
Region 3     
San Benito River
 
LOE ID: 162938
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 23
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 San Benito River to determine beneficial use support and results are as follows: 0 of 23 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107234, Copper
Region 3     
San Benito River
 
LOE ID: 163102
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
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 San Benito River to determine beneficial use support and the results are as follows: 2 of the 12 samples exceeded the water quality threshold for Copper. Although a total of 24 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 (305SAN).
Temporal Representation: Data for this waterbody was collected over the date range 2011-01-12 to 2017-12-12
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 107234, Copper
Region 3     
San Benito River
 
LOE ID: 162934
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 24 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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
107240
Region 3     
San Benito River
 
Pollutant: Lead
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: No Source Analysis Available
Expected TMDL Completion Date: 2035
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

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

Zero of the 8 dissolved lead samples exceed the water quality objective aquatic life beneficial uses.

Four of the 8 dissolved lead samples exceed the evaluation guideline for Municipal and Domestic Supply and 0 of hte 8 dissolved lead samples exceed the evaluation guideline for Agriculture Supply.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should 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. Four of the 8 dissolved lead samples exceed the evaluation guideline for Municipal and Domestic Supply. These do exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) List because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 107240, Lead
Region 3     
San Benito River
 
LOE ID: 168262
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107240, Lead
Region 3     
San Benito River
 
LOE ID: 168310
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107240, Lead
Region 3     
San Benito River
 
LOE ID: 168244
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107240, Lead
Region 3     
San Benito River
 
LOE ID: 168287
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area data for San Benito River to determine beneficial use support and results are as follows: 0 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107240, Lead
Region 3     
San Benito River
 
LOE ID: 168194
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
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 San Benito River to determine beneficial use support and results are as follows: 3 of 4 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 waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Public Health Goal for lead in sources of drinking water is 0.0002 mg/L. (OEHHA 2009)
Guideline Reference: Public Health Goal for Lead in Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107240, Lead
Region 3     
San Benito River
 
LOE ID: 168243
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
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 San Benito River to determine beneficial use support and results are as follows: 1 of 4 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 waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The California Public Health Goal for lead in sources of drinking water is 0.0002 mg/L. (OEHHA 2009)
Guideline Reference: Public Health Goal for Lead in Drinking Water
 
Spatial Representation: The samples were collected at 1 monitoring site (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
107242
Region 3     
San Benito River
 
Pollutant: Manganese
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: No Source Analysis Available
Expected TMDL Completion Date: 2035
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the Clean Water Act (CWA) section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

A total of two lines of evidence are available in the administrative record to assess this pollutant. A total of three of eight 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 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 three of eight samples exceed the water quality objective for the agricultural supply beneficial use. This exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 107242, Manganese
Region 3     
San Benito River
 
LOE ID: 168915
 
Pollutant: Manganese
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
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 San Benito River to determine beneficial use support and results are as follows: 2 of 4 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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 107242, Manganese
Region 3     
San Benito River
 
LOE ID: 168967
 
Pollutant: Manganese
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 4
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 San Benito River to determine beneficial use support and results are as follows: 1 of 4 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2017-03-09 and 2017-12-12
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
107251
Region 3     
San Benito River
 
Pollutant: Toxicity
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Delist from 303(d) list (TMDL required list)(2018)
Revision Status Revised
Sources: No Source Analysis Available
Reason for Delisting: Flaws in original listing
Expected TMDL Completion Date: 2035
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 4.1 and 4.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

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

Six LOEs summarize water samples. Three out of 9 samples were toxic to test organisms (exhibited a significant increase in mortality, decrease in cell density, decrease in growth or reproduction compared to the laboratory control) and therefore exceeded the narrative general water quality objective for toxicity, set to protect for aquatic life beneficial uses.

Note that the exceedances in LOE 24397 are not counted as exceedances. Both samples had specific conductivities above the tolerance level of the test organism. According to SWAMP guidance (July 2013) for S. capricornutum toxicity testing should 1) include appropriate salinity controls when sample conductivities exceed 1500 uS/cm and 2) if conductivity exceeds 3000 uS/cm, use alternate species or forgo testing. The conductivity of the sample water from both January 2006 and May 2006 was higher than 1500 uS/cm, the threshold for which a high salinity control should have been used to evaluate the toxicity of the sample. The significance of the toxic effect for the two samples results summarized in this LOE (24397) were not calculated using the high salinity control sample and therefore should not be used. Therefore, the sample and exceedance count for this decision do not include these two samples.

Two LOEs summarize sediment samples. Zero out of 2 samples were toxic to test organisms (exhibited a significant increase in mortality, decrease in cell density, decrease in growth or reproduction compared to the laboratory control) which does not exceed the narrative general water quality objective for toxicity, set to protect for aquatic life beneficial uses.

Based on the readily available data and information, the weight of evidence indicates that 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.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Three out of 9 water samples were toxic to test organisms relative to the control and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) List because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 107251, Toxicity
Region 3     
San Benito River
 
LOE ID: 57757
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 1
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Five samples were collected to evaluate water toxicity. One of the five samples exhibited significant toxicity. The toxicity tests for the samples included survival and reproduction of Ceriodaphnia dubia, survival and growth of Pimephales promelas and total cell count (growth) of Selenastrum capricornutum. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day at the same location. The sample collected on 9/30/14 exhibited significant toxicity to the reproduction and survival of Ceriodaphnia dubia.
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Significant effect is defined here using a two-tier approach consistent with the method used by the SWAMP program. The effect must be significant when compared to the control sample based on statistical test alpha level of 0.05 (Probability field in data set) AND the mean must be more than 20 percent different from the control (PercentControl field in data set).
Guideline Reference: Major and Trace Element Analytical Methods of the National Status and Trends Program: 2000-2006.
 
Spatial Representation: The samples were collected at 305SAN-San Benito River at Y Road and at 305SBH - San Benito River @ Hollister near 156.
Temporal Representation: The samples were collected from January 2008 - September 2008.
Environmental Conditions:
QAPP Information: The data was collected for the CCRWQCB Cooperative Monitoring Program for Agriculture data and provided in SWAMP format. The Project QAPP was provided.
QAPP Information Reference(s): 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)
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 107251, Toxicity
Region 3     
San Benito River
 
LOE ID: 24396
 
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 San Benito River 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 1/10/2006-5/17/2006. 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 107251, Toxicity
Region 3     
San Benito River
 
LOE ID: 148917
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: 2 of the 2 samples collected by SWAMP RWB3 CCAMP Pajaro and Santa Cruz Area for San Benito River exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Selenastrum capricornutum, for Total Cell Count, Ceriodaphnia dubia, for Young/female, Pimephales promelas, for Survival, Ceriodaphnia dubia, for Survival, Pimephales promelas, for Biomass (wt/orig indiv)
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. 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 for the Central Coastal Basin
 
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: Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064
Guideline Reference: SWAMP_Memo_Toxicity_Data_Intrepretation
 
Spatial Representation: The samples were collected at 1 station. Monitoring site: ( 305SAN )
Temporal Representation: The samples were collected between the dates of 2011-02-24 and 2011-09-21.
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 107251, Toxicity
Region 3     
San Benito River
 
LOE ID: 24384
 
Pollutant: Invertebrate Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: Final Data File used for assessment: 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/3/2006. 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 107251, Toxicity
Region 3     
San Benito River
 
LOE ID: 24397
 
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: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for San Benito River to determine beneficial use support and results are as follows: 2 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 1/10/2006-5/17/2006. 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 107251, Toxicity
Region 3     
San Benito River
 
LOE ID: 57758
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: One sample was collected to evaluate sediment toxicity. The sample did not exhibit significant toxicity. The toxicity tests for the sample included survival and growth of Hyalella azteca.
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Significant effect is defined here using a two-tier approach consistent with the method used by the SWAMP program. The effect must be significant when compared to the control sample based on statistical test alpha level of 0.05 (Probability field in data set) AND the mean must be more than 20 percent different from the control (PercentControl field in data set).
Guideline Reference: Major and Trace Element Analytical Methods of the National Status and Trends Program: 2000-2006.
 
Spatial Representation: The sample was collected at 305SAN-San Benito at Y Road and 305SBH - San Benito River @ Hollister near 156.
Temporal Representation: The sample was collected on 5/1/2008.
Environmental Conditions:
QAPP Information: The data was collected for the CCRWQCB Cooperative Monitoring Program for Agriculture data and provided in SWAMP format. The Project QAPP was provided.
QAPP Information Reference(s): 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)
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 107251, Toxicity
Region 3     
San Benito River
 
LOE ID: 24385
 
Pollutant: Invertebrate Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference: Final Data File used for assessment: 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected on a single day 1/10/2006. 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 107251, Toxicity
Region 3     
San Benito River
 
LOE ID: 24253
 
Pollutant: Invertebrate Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 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 San Benito River was collected at 1 monitoring site [ 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected on a single day 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
107253
Region 3     
San Benito River
 
Pollutant: Turbidity
Final Listing Decision: 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
Sources: No Source Analysis Available
Expected TMDL Completion Date: 2035
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the 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 five 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 65 of 150 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 use.

After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) List.

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 65 of 150 samples exceed the evaluation guideline for warm freshwater habitat and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 107253, Turbidity
Region 3     
San Benito River
 
LOE ID: 183072
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 25
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 San Benito River to determine beneficial use support and results are as follows: 5 of 25 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 (305SAN)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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 107253, Turbidity
Region 3     
San Benito River
 
LOE ID: 17522
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 71
Number of Exceedances: 42
 
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 San Benito River to determine beneficial use support and results are as follows: 42 of 71 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 San Benito River was collected at 4 monitoring sites [ SB-YRD - San Benito River at Y Road, SB-PA - San Benito River at Pajaro junction, SB-BWC - San Benito River at below Willow Creek, SB-BHR - San Benito River at below Hernandez Reservoir]
Temporal Representation: Data was collected over the time period 9/28/2005-2/22/2007.
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 107253, Turbidity
Region 3     
San Benito River
 
LOE ID: 12283
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 29
Number of Exceedances: 11
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 11 of 29 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 12/18/1997-3/14/2006. 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 107253, Turbidity
Region 3     
San Benito River
 
LOE ID: 48980
 
Pollutant: Turbidity
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: Central Coast Water Board Staff assessed public submissions data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Turbidity(NTU).
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
SWAMP Data: Non-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 40 NTU or greater can cause a reduction in piscivorous fish (largemouth bass) growth due to interference with their ability to find food (Shoup, D.E. and Wahl D.H., 2009).
Guideline Reference: The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
 
Spatial Representation: Data for this line of evidence for San Benito River was collected at 1 monitoring site [ 305SANxxx - San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/1/2008.
Environmental Conditions: Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
Line of Evidence (LOE) for Decision ID 107253, Turbidity
Region 3     
San Benito River
 
LOE ID: 182191
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 24
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 San Benito River to determine beneficial use support and results are as follows: 5 of 24 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 (305BRI)
Temporal Representation: The samples were collected between the dates of 2011-01-12 and 2017-12-12
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
107232
Region 3     
San Benito River
 
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 CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 41 samples exceed the evaluation guideline (North Carolina Administrative code, Title 15A) used to interpret the narrative water quality objective for bio-stimulation risk and 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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of the 41 samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 107232, Chlorophyll-a
Region 3     
San Benito River
 
LOE ID: 9265
 
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: 40
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 San Benito River to determine beneficial use support and results are as follows: 0 of 40 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 2/19/1998-3/14/2006. 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 107232, Chlorophyll-a
Region 3     
San Benito River
 
LOE ID: 48942
 
Pollutant: Chlorophyll-a
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: Central Coast Water Board Staff assessed public submissions data for San Benito River to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlorophyll a.
Data Reference: Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
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: Water quality standards table
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 San Benito River was collected at 1 monitoring site [ 305SANxxx - San Benito at Y Road]
Temporal Representation: Data was collected on a single day 5/1/2008.
Environmental Conditions: Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6
 
 
DECISION ID
80889
Region 3     
San Benito River
 
Pollutant: Boron
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.1 of the Listing Policy.

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

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Twenty-four of 30 samples exceeded the water quality objective for Agricultural Supply and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 80889, Boron
Region 3     
San Benito River
 
LOE ID: 9262
 
Pollutant: Boron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 30
Number of Exceedances: 24
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for San Benito River to determine beneficial use support and results are as follows: 24 of 30 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 San Benito River was collected at 2 monitoring sites [ 305BRI-San Benito River at Highway 25, 305SAN-San Benito at Y Road]
Temporal Representation: Data was collected over the time period 1/24/2005-3/14/2006. 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
69397
Region 3     
San Benito River
 
Pollutant: Sedimentation/Siltation
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status Original
Sources: Agriculture | Grazing-Related Sources | Harvesting, Restoration, Residue Management | Highway/Road/Bridge Runoff | Hydromodification | Road Construction | Surface Mining | Urban Runoff/Storm Sewers
TMDL Name: Pajaro River Siltation/Sedimentation (including San Benito R., Llagas Cr., Rider Gulch Cr.)
TMDL Project Code: 140
Date TMDL Approved by USEPA: 05/03/2007
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 listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. There are no data associated with this decision however, the Pajaro River Siltation/Sedimentation TMDL (including San Benito R., Llagas Cr., Rider Gulch Cr.) was approved for this water segment-pollutant combination by USEPA on 5/03/07.

Based on the readily available information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.
 
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 69397, Sedimentation/Siltation
Region 3     
San Benito River
 
LOE ID: 1859
 
Pollutant: Sedimentation/Siltation
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information: QA Info Missing
QAPP Information Reference(s):