| Water Body Name: | Russian Gulch |
| Water Body ID: | CAC1134000020190116035773 |
| Water Body Type: | Coastal & Bay Shoreline |
DECISION ID |
168930 |
Region 1 |
Russian Gulch |
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| Pollutant: | Indicator Bacteria |
| Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2018) |
| Revision Status | Original |
| Sources: | A Source Unknown |
| TMDL Priority: | Low |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Lacking constant inputs, indicator bacteria do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Historic lines of evidence for data collected prior to October 21, 2012 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. No data has been collected from on or after October 21, 2012 and so the existing decision will carry-over. When no data after the October 21, 2012, timeframe were available, the historic data were evaluated to represent water quality conditions. Beneficial use support will be reassessed in a future cycle, if more data are available. This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. ***DO NOT LIST REC-1 BENEFICIAL USE*** Enterococcus has one LOE (133588) and 0 of 7 geometric means exceed the REC-1 beneficial use objective, which is insufficient data to apply the AB411 coastal beaches exceedance frequency in the Listing Policy. ***DO NOT DELIST SHELL BENEFICIAL USE*** Total Coliform has one LOE (133671) and 7 of 15 median concentrations exceed the SHELL beneficial use objective, and this exceeds the allowable frequency in Table 4.2 of the Listing Policy. 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 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. Total Coliform has one LOE (133671) and 7 of 15 median concentrations exceed the SHELL beneficial use objective, and this exceeds the allowable frequency 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. This listing applies to the entire waterbody. |
| 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: | |
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| LOE ID: | 133588 | ||||
| Pollutant: | Enterococcus | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 7 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Beachwatch_Mendocino County data for Russian Gulch to determine beneficial use support and the results are as follows: 0 of the 7 samples exceeded the geomean water quality standard for Enterococcus. This is a six week rolling geomean that is calculated weekly. | ||||
| Data Reference: | Mendocino County Beachwatch data reformatted and renamed to match CEDEN fields. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective to protect the REC-1 beneficial for all ocean waters , is a six-week rolling GM of Enterococci not to exceed 30 cfu/100mL (calculated weekly). | ||||
| Objective/Criterion Reference: | California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009 | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site(s), station(s): Russian Gulch | ||||
| Temporal Representation: | The samples were collected between the days of 2003-01-29 and 2003-06-09 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Data exempt from QAPP requirement. Draft QAPP for Mendocino County Beachwatch data used instead. Represents data collection procedure prior to development of a formal QAPP. | ||||
| QAPP Information Reference(s): | Draft QAPP for Mendocino County Beachwatch. Represents data collection procedure prior to development of a formal QAPP. | ||||
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| LOE ID: | 133671 | ||||
| Pollutant: | Total Coliform | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Shellfish Harvesting | ||||
| Number of Samples: | 15 | ||||
| Number of Exceedances: | 7 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Beachwatch_Mendocino County data for Russian Gulch to determine beneficial use support and the results are as follows: 7 of the 15 samples exceeded the water quality standard for Coliform, Total. The water quality standard for shellfish is based on the median concentration of Total Coliform at each station, and is calculated on a monthly basis. | ||||
| Data Reference: | Mendocino County Beachwatch data reformatted and renamed to match CEDEN fields. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | California Ocean Plan (SWRCB 2018) states that the median concentration of total coliform samples shall not exceed 70 per 100 ml. | ||||
| Objective/Criterion Reference: | California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009 | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site(s), station(s): Russian Gulch | ||||
| Temporal Representation: | The samples were collected between the days of 2003-01-29 and 2003-06-18 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Data exempt from QAPP requirement. Draft QAPP for Mendocino County Beachwatch data used instead. Represents data collection procedure prior to development of a formal QAPP. | ||||
| QAPP Information Reference(s): | Draft QAPP for Mendocino County Beachwatch. Represents data collection procedure prior to development of a formal QAPP. | ||||