Draft California 2016 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Matilija Creek, North Fork
Water Body ID: CAR4022001420081125170446
Water Body Type: River & Stream
 
DECISION ID
66262
Region 4     
Matilija Creek, North Fork
 
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 Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: Benthic Community Effects is being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, an additional line of evidence associating the Benthic Community Effects with a water or sediment concentration of pollutants is necessary to assess listing status. All of the samples had IBI scores above 40.

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 water 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. All of the samples had IBI scores above 40 indicating that the benthic community is intact.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

The CSCI is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs).
 
Regional Board Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66262, Benthic Community Effects
Region 4     
Matilija Creek, North Fork
 
LOE ID: 86482
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Four samples were collected at two sites on Matilija Creek in September 2006 and 2007. All of the samples had IBI scores above 40. The scores were 47.19 at site 10 and 50.34 at site 11 (2006) and 47 at site 10 and 67 at site 11 (2007).
Data Reference: Development of a Benthic Index of Biotic Integrity (B-IBI) for Wadeable Streams in Northern Coastal California and its Application to Regional 305(b) Assessment
  Bioassessment Monitoring Report in Ventura River Watershed for, 2001-2007.
 
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 or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the State or Regional Board. Region 4 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The IBI is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked. For the Southern California IBI, sites with scores below 40 are considered to have impaired conditions.
Guideline Reference: Development of a Benthic Index of Biotic Integrity (B-IBI) for Wadeable Streams in Northern Coastal California and its Application to Regional 305(b) Assessment
 
Spatial Representation: The samples were collected at sites 10 North Fork Matilija Creek above influence of Matilija Dam and below rock quarry and site 11 North Fork Matilija Creek- at gauging station.
Temporal Representation: The samples were collected in September 2006 and 2007.
Environmental Conditions:
QAPP Information: Sampling and laboratory procedures for this survey followed the California Stream Bioassessment Procedure (CSBP 2003) and also incorporated the Southern California Index of Biotic Integrity (IBI) (Ode et al., 2005).
QAPP Information Reference(s):
 
 
DECISION ID
39875
Region 4     
Matilija Creek, North Fork
 
Pollutant: Indicator Bacteria
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)(2012)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 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. One of 72 samples exceeded the Basin Plan Water Quality Objects for E. coli 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.
 
Regional Board Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 39875, Indicator Bacteria
Region 4     
Matilija Creek, North Fork
 
LOE ID: 25849
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 72
Number of Exceedances: 1
 
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 one out of 72 samples for E. coli exceeded the single sample limit.
Data Reference: Santa Barbara Channelkeeper Water Quality Data Submittal and 303(d) List Recommendations
 
SWAMP Data: Non-SWAMP
 
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
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: VR14 sampling site is located below a bridge on Highway 33 used a Ventura County flood gauging station (Lat 34.492778, Long -119.306389).
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
39224
Region 4     
Matilija Creek, North Fork
 
Pollutant: Total Dissolved Solids
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)(2012)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 lines of evidence are available in the administrative record to assess this pollutant. Zero 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. Zero of 60 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.
 
Regional Board Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 39224, Total Dissolved Solids
Region 4     
Matilija Creek, North Fork
 
LOE ID: 25851
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 60
Number of Exceedances: 0
 
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 zero out of 60 exceeded the water quality objective of 700 mg/L for TDS. By the tributary rule the same objective applies to Matilija Creek, North Fork.
Data Reference: Santa Barbara Channelkeeper Water Quality Data Submittal and 303(d) List Recommendations
 
SWAMP Data: Non-SWAMP
 
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
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: VR14 sampling site is located below a bridge on Highway 33 used a Ventura County flood gauging station (Lat 34.492778, Long -119.306389).
Temporal Representation: Grab samples taken and analyzed on monthly basis from November 2001 to December 2006.
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)