| Water Body Name: | San Vicente Creek |
| Water Body ID: | CAR2022101220010905121128 |
| Water Body Type: | River & Stream |
DECISION ID |
148715 |
Region 2 |
San Vicente Creek |
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| Pollutant: | Indicator Bacteria |
| Final Listing Decision: | Do Not Delist from 303(d) list (being addressed with action other than TMDL) |
| Last Listing Cycle's Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)(2018) |
| Revision Status | Revised |
| Sources: | A Source Unknown | Agriculture-animal | Onsite Wastewater Systems (Septic Tanks) |
| Expected Attainment Date: | 2037 |
| Implementation Action Other than TMDL: | The San Francisco Bay Regional Water Quality Control Board, at its May 11, 2016 hearing, adopted a Resolution to support the Water Quality Improvement Plan for bacteria in San Vicente Creek. The Plan describes bacteria sources in the San Vicente Creek watershed, proposes high-priority implementation actions to reduce loading from horse waste, dog waste, human waste from onsite wastewater treatment systems, and stormwater runoff and identifies the regulatory mechanisms for the actions. The Plan also includes water quality monitoring to evaluate effectiveness of the corrective actions and assess attainment of standards. |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for removal from the section 303(d) list under section 4.3 of the Listing Policy. Under section 4.3 a single line of evidence is necessary to assess delisting status. Two lines of evidence are 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. The San Francisco Bay Regional Water Quality Control Board, at its May 11, 2016 hearing, adopted a Resolution to support the Water Quality Improvement Plan for bacteria in San Vicente Creek. Therefore, there is justification for moving this impairment to the category of listings being addressed by an action other than a TMDL. 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. |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded. |
| 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. |
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| 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) | ||||
| SWAMP Data: | Non-SWAMP | ||||
| 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 |
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| 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): | |||||
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| LOE ID: | 300209 | ||||
| Pollutant: | Enterococcus | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | STV | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 1 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed BeachWatch_San Mateo County data for San Vicente Creek to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for Enterococcus. The STV is based on a 10% exceedance rate that is calculated monthly. | ||||
| Data Reference: | WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is 1 ppth or higher 95 percent or more of the time applies a Statistical Threshold Value to enterococcus of 110 cfu/100 mL, not to be exceeded by more than 10 percent of samples collected within in a calendar month. (ISWEBE 2018) | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site(s), station(s): San Vicente Creek (San Vicente Creek-Montara State Beach, San Mateo). | ||||
| Temporal Representation: | The samples were collected between the days of 2018-10-09 and 2018-10-09 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | State Board Staff. 2021. QAPP Reference for Beach Watch Program. | ||||
| QAPP Information Reference(s): | QAPP Reference for Beach Watch Program | ||||