Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: San Antonio Creek (Tributary to Ventura River Reach 4)
Water Body ID: CAR4022002320020131162536
Water Body Type: River & Stream
 
DECISION ID
13186
Region 4     
San Antonio Creek (Tributary to Ventura River Reach 4)
 
Pollutant: Indicator Bacteria
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status.

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

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. 46 of 263 samples exceeded the Basin Plan water quality objects for indicator bacteria in fresh water, 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 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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 13186, Indicator Bacteria
Region 4     
San Antonio Creek (Tributary to Ventura River Reach 4)
 
LOE ID: 25712
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 263
Number of Exceedances: 46
 
Data and Information Type: Other Agencies/Organizations provided monitoring data
Data Used to Assess Water Quality: The Basin Plan bacteria objectives state that to protect water contact recreation in fresh waters individual samples shall not exceed the following limits: fecal coliform density shall not exceed 400/100 ml; and E. coli density shall not exceed 235/100 ml. The bacteria objectives also establish that the geometric means of individual samples shall not exceed the following limits: the fecal coliform density shall not exceed 200/100 ml; and the E. coli density shall not exceed 126/100 ml, as a geometric mean. The bacteria objectives are found in Attachment A of Regional Board Resolution No. 2001-018.
Data Reference: Santa Barbara Channelkeeper Water Quality Data Submittal and 303(d) List Recommendations
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The updated Basin Plan bacteria objectives states that E. coli density shall not exceed 235/100 ml and Fecal Coliform density shall not exceed 400/100 ml as single sample limits to protect water contact recreation in fresh water. The bacteria objectives also add that E. coli density shall not exceed 126/100 ml and Fecal coliform density shall not exceed 200/100 ml as geometric mean limits to protect water contact recreation in fresh water. The updated bacteria objectives are included in Basin Plan Amendment 2001-018.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: VR07 sampling site is located at the Old Creek Road low water crossing, just off of Highway 33 (Lat 34.38700, Long -119.30700). VR08 sampling site is located just before Lion Creek enters San Antonio Creek (Lat 34.422022, Long -119.263552). VR09 sampling site is located just before Pirie Creek enters San Antonio Creek (Lat 34.434208, Long -119.24862). VR10 sampling site is located upper San Antonio Creek (Lat 34.433809, Long -119.24872).
Temporal Representation: Grab samples taken and analyzed on monthly basis from January 2001 to February 2007.
Environmental Conditions:
QAPP Information: Data collected and analyzed according to the provisions of the Ventura River Watershed Monitoring Program Quality Assurance Project Plan (Santa Barbara Channelkeeper, October 2004).
QAPP Information Reference(s): Ventura River Watershed Monitoring Program Quality Assurance Project Plan (Santa Barbara Channelkeeper, October 2004)
 
 
DECISION ID
13194
Region 4     
San Antonio Creek (Tributary to Ventura River Reach 4)
 
Pollutant: Total Dissolved Solids
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2023
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One line of evidence are available in the administrative record to assess this pollutant.
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. 74 of 222 samples exceed the Basin Plan water quality objective (reach specific) of 800 mg/L for TDS, 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 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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 13194, Total Dissolved Solids
Region 4     
San Antonio Creek (Tributary to Ventura River Reach 4)
 
LOE ID: 25715
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 222
Number of Exceedances: 74
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Data collected for the Santa Barbara ChannelKeeper Water Quality Monitoring Program (2001 to 2007). A total of 74 out of 222 samples exceeded the water quality objective of 800 mg/L.
Data Reference: Santa Barbara Channelkeeper Water Quality Data Submittal and 303(d) List Recommendations
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Los Angeles RWQCB Basin Plan Water Quality Objective for Selected Constituents in Inland Surface Waters--water body specific for Ventura River Reach 4--is 800 mg/L for TDS. By the tributary rule this objective also applies to San Antonio Creek.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: VR07 sampling site is located at the Old Creek Road low water crossing, just off of Highway 33 (Lat 34.38700, Long -119.30700). VR08 sampling site is located just before Lion Creek enters San Antonio Creek (Lat 34.422022, Long -119.263552). VR09 sampling site is located just before Pirie Creek enters San Antonio Creek (Lat 34.434208, Long -119.24862). VR10 sampling site is located upper San Antonio Creek (Lat 34.433809, Long -119.24872).
Temporal Representation: Grab samples taken and analyzed on monthly basis from January 2001 to February 2007.
Environmental Conditions:
QAPP Information: Data collected and analyzed according to the provisions of the Ventura River Watershed Monitoring Program Quality Assurance Project Plan (Santa Barbara Channelkeeper, October 2004).
QAPP Information Reference(s): Ventura River Watershed Monitoring Program Quality Assurance Project Plan (Santa Barbara Channelkeeper, October 2004)
 
 
DECISION ID
4839
Region 4     
San Antonio Creek (Tributary to Ventura River Reach 4)
 
Pollutant: Nitrogen
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)(2006)
Revision Status Original
Sources: Source Unknown
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under section 4.1 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. This line of evidence was used to place this water body pollutant combination on the 303(d) list originally. Four of the samples exceeded the nitrogen site specific water quality objective in this line of evidence but the number of samples is insufficient to make a delisting determination with the confidence and power required by the Listing Policy.

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

This conclusion is based on the staff findings that:
1.The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
1.The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3.Four of 23 samples exceeded the nitrogen site specific water quality objective, but the number of samples is insufficient to determine with the confidence and power required by 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: 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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 4839, Nitrogen
Region 4     
San Antonio Creek (Tributary to Ventura River Reach 4)
 
LOE ID: 2004
 
Pollutant: Nitrogen
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 23
Number of Exceedances: 4
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Twenty-three water samples, 4 samples exceeding (SWRCB, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Basin Plan: 5 mg/L (as NO3-N and NO2-N). Table 3-8 of the Basin Plan.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Two sample sites.
Temporal Representation: Winter 1998 - Summer 2000.
Environmental Conditions:
QAPP Information: Ojai Valley Wastewater Treatment Plant.
QAPP Information Reference(s):