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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Matilija Creek Reach 1 (Jct. With N. Fork to Reservoir)
Water Body ID: CAR4022001219990202161144
Water Body Type: River & Stream
 
DECISION ID
13423
 
Pollutant: Indicator Bacteria
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.3 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 against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 70 samples exceeded the updated Basin Plan water quality objects for bacterial indicator to protect REC-1 beneficial uses, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 13423
 
LOE ID: 25839
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 70
Number of Exceedances: 0
 
Data and Information Type: Other Agencies/Organizations provided monitoring data
Data Used to Assess Water Quality: Data collected for the Santa Barbara ChannelKeeper Water Quality Monitoring Program (2001 to 2007). A total of zero (0) out of 70 for E. coli samples exceeded the single sample limit (Santa Barbara ChannelKeeper, 2007).
Data Reference: Santa Barbara Channelkeeper Water Quality Data Submittal and 303(d) List Recommendations
 
Water Quality Objective/Criterion: 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.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: VR13 sampling site is located at an out-of-use USGS stream gauging station approximately one kilometer downstream of Matilija Dam (Lat 34.483056, Long -119.301944).
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
13289
 
Pollutant: Total Dissolved Solids
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One line of evidence are available in the administrative record to assess this pollutant. Three of the samples exceed the water quality objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Three of 58 samples exceeded the Los Angeles RWQCB Basin Plan Water Quality Objective for Selected Constituents in Inland Surface Waters (water body specific for Ventura River Reach 5) of 700 mg/L for TDS, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 13289
 
LOE ID: 25753
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 58
Number of Exceedances: 3
 
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 three of 58 exceeded the water quality objective of 700 mg/L for TDS. By the tributary rule the same objective applies to Matilija Creek Reach 1.
Data Reference: Santa Barbara Channelkeeper Water Quality Data Submittal and 303(d) List Recommendations
 
Water Quality Objective/Criterion: The Los Angeles RWQCB Basin Plan Water Quality Objective for Selected Constituents in Inland Surface Waters--water body specific for Ventura River Reach 5--is 700 mg/L for TDS.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: VR13 sampling site is located at an out-of-use USGS stream gauging station approximately one kilometer downstream of Matilija Dam (Lat 34.483056, Long -119.301944).
Temporal Representation: Grab samples taken and analyzed on monthly basis from November 2001 to January 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)