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

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name: San Vicente Creek
Water Body ID: CAR2022101220010905121128
Water Body Type: River & Stream
 
DECISION ID
4188
 
Pollutant: Coliform Bacteria
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: Nonpoint Source
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for removal from the section 303(d) list under section 4.3 of the Listing Policy. Under section 4.3 a single line of evidence is necessary to assess delisting status.

One line of evidence is available in the administrative record to assess this pollutant. A large number of 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 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.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. All samples exceeded the fecal and total coliform water quality objectives 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.
 
RWQCB Board Decision / Staff Recommendation: No new data were assessed for 2008. The Regional Board will update this decision when new data and information become available and are assessed.
 
SWRCB Board Decision / Staff Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be removed from on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 4188
 
LOE ID: 1770
 
Pollutant: Coliform Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 38
Number of Exceedances: 38
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Thirty-eight samples for total coliform, 22 samples for fecal coliform, and 6 samples for E. coli. E. coli data show 100% violations of the Basin Plan Objectives for total coliform maximum at all beaches in dry-weather months. Basin Plan violated in 3% of samples for total coliform maximum, 100% samples violated for total coliform median, 100% samples violated for fecal coliform geomean and 100% samples violated for fecal coliform (REC-1). Basin Plan objectives violated in 32% of samples for fecal coliform mean, and 23% violated samples for fecal coliform (REC-2) in dry-weather months (SWRCB, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
Water Quality Objective/Criterion: Basin Plan objectives (SFBRWQCB, 1995)
Fecal coliform
Log mean <200 MPN/100ml
90th percentile <400 MPN/100ml
Total coliform
Log mean <240 MPN/100ml
90th percentile >10,000 MPN/100ml
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data was spatially collected.
Temporal Representation: Data was collected from 10/6/98-9/26/00.
Environmental Conditions:
QAPP Information: San Mateo County Environmental Health Department. Beach Monitoring, Surfrider data/lab QA/QC used. Data evaluation was based on USEPA guidelines for 305(b) reports, that uses a hierarchy of water quality data levels. Only data of higher overall level of information (Levels 3 and 4) were used to list a water body.
QAPP Information Reference(s):