Draft California 2014 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: San Nicolas Canyon Creek
Water Body ID: CAR4044300020050623112742
Water Body Type: River & Stream
 
DECISION ID
67427
Region 4     
San Nicolas Canyon Creek
 
Pollutant: Trash
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 Staff Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant. 4 of the 6 samples exceed the guideline.

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. 4 of 6 samples exceeded the 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 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 67427, Trash
Region 4     
San Nicolas Canyon Creek
 
LOE ID: 96033
 
Pollutant: Trash
LOE Subgroup: Pollutant-Nuisance
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 6
Number of Exceedances: 4
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Four of the 6 samples exceed the narrative objective. Trash was observed and counted as part of the sampling efforts of the Ventura Coastkeepers.
Data Reference: Data for Various Pollutants from Wishtoyo Foundation's Ventura Coastkeeper, 2009-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: From the Los Angeles RWQCB Basin Plan: Waters shall not contain floating materials, including solids, liquids, foams, and scum, in concentrations that cause nuisance or adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The Los Angeles River Trash TMDL derived a numeric target for trash to evaluate the narrative guidelines listed in the Basin Plan. This target was derived as 0 for trash to fully support beneficial uses and also includes a margin of safety.
Guideline Reference: Trash Total Maximum Daily Loads for the Los Angeles River Watershed Revised Draft Staff Report. California Regional Water Quality Control Board, Los Angeles Region. July 27, 2007.
 
Spatial Representation: The following sites were surveyed: NC-1 and NC-01 (Nicholas Canyon Creek downstream PCH) and NC-5 (Pond at Nicholas Canyon Flats),
Temporal Representation: NC-1 was surveyed January, June and August of 2010. NC-01 was surveyed July 2010. NC-5 was surveyed June 2010.
Environmental Conditions:
QAPP Information: Wishtoyo Foundation volunteer monitoring QAPP was provided.
QAPP Information Reference(s): Quality Assurance Project Plan from Wishtoyo Foundation.
 
 
DECISION ID
33438
Region 4     
San Nicolas Canyon Creek
 
Pollutant: Sulfates
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 line of evidence is available in the administrative record to assess this pollutant. An insufficient total number of samples were taken and an insufficient number of samples exceed the MCL guideline for Sulfate.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient 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.Four of four samples exceeded the MCL guideline. More data is needed to determine if the water quality standard is exceeded.
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 33438, Sulfates
Region 4     
San Nicolas Canyon Creek
 
LOE ID: 2279
 
Pollutant: Sulfates
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 4
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Four samples with four exceeding. (SWAMP, 2004).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: CCR- Title 22 Table 64449-B Secondary Maximum Contaminant Levels of 250 mg/l for Sulfate.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Two stations at San Nicholas Canyon Creek Upper 34.04744 -118.91288 and at San Nicholas Canyon Creek Lower 34.04516 -118.91352.
Temporal Representation: Samples were collected March 2003 through March 2004.
Environmental Conditions: Los Angeles County Coastal Streams: 404.43.
QAPP Information: SWAMP Quality Assurance Plan.
QAPP Information Reference(s):