| Water Body Name: | Pacific Ocean at Gazos Creek Beach |
| Water Body ID: | CAC3042001020110923101045 |
| Water Body Type: | Coastal & Bay Shoreline |
DECISION ID |
129345 |
Region 3 |
Pacific Ocean at Gazos Creek Beach |
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| Pollutant: | Enterococcus |
| 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)(2018) |
| Revision Status | Revised |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board 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. Four lines of evidence are available in the administrative record to assess this pollutant. Nineteen of the 308 GM samples exceed the REC-1 enterococci 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 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. Nineteen of the 308 GM samples exceed the REC-1 enterococci water quality objective 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. The Water Quality Control Plan for Ocean Waters (“Ocean Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use:¿ a fecal coliform water quality objective and an¿enterococci water quality objective.¿¿¿¿This waterbody is being considered for placement on the CWA section 303(d) List under section 3.3 of the Listing Policy, as applicable, using the enterococci objective.¿¿¿ 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.¿¿Indicator bacteria (total coliform, fecal coliform,¿E. coli, enterococci)¿populations¿may¿fluctuate substantially on a daily, seasonal, or yearly basis.¿¿Lacking¿constant inputs,¿they do¿not persist in the environment¿for a long period and¿effects are of relatively short duration.¿¿As a result,¿the¿historic levels¿of¿indicator 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.¿¿Additionally,¿water quality¿conditions¿in waterbodies¿may¿change¿as a result of management actions that have been implemented to address¿bacteria.¿¿Unrepresentative data¿may¿result in incorrectly placing or not placing a water body segment on the¿list, which¿could result in the unnecessary expenditure of public resources or missing a¿human health¿problem.¿¿Historic lines of evidence for data collected prior to 2010¿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.¿¿¿ For¿enterococci data,¿Listing Policy sections 3.3¿and 4.3¿instructs to use the binomial distribution table in sections 3.2¿and 4.2, as applicable. To¿use the binomial table¿that uses a four percent exceedance frequency, the data must be collected¿from coastal beaches from¿April 1 through October 31 only. |
| Regional Board 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. |
| State Board Review of Regional Board Conclusion and Recommendation: | The Water Quality Control Plan for Ocean Waters (“Ocean Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use:¿ a fecal coliform water quality objective and an¿enterococci water quality objective.¿¿¿¿This waterbody is being considered for placement on the CWA section 303(d) List under section 3.3 of the Listing Policy, as applicable, using the enterococci objective.¿¿¿ 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.¿¿Indicator bacteria (total coliform, fecal coliform,¿E. coli, enterococci)¿populations¿may¿fluctuate substantially on a daily, seasonal, or yearly basis.¿¿Lacking¿constant inputs,¿they do¿not persist in the environment¿for a long period and¿effects are of relatively short duration.¿¿As a result,¿the¿historic levels¿of¿indicator 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.¿¿Additionally,¿water quality¿conditions¿in waterbodies¿may¿change¿as a result of management actions that have been implemented to address¿bacteria.¿¿Unrepresentative data¿may¿result in incorrectly placing or not placing a water body segment on the¿list, which¿could result in the unnecessary expenditure of public resources or missing a¿human health¿problem.¿¿Historic lines of evidence for data collected prior to 2010¿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.¿¿¿ For¿enterococci data,¿Listing Policy sections 3.3¿and 4.3¿instructs to use the binomial distribution table in sections 3.2¿and 4.2, as applicable. To¿use the binomial table¿that uses a four percent exceedance frequency, the data must be collected¿from coastal beaches from¿April 1 through October 31 only. |
| State Board Decision Recommendation: | After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded. |
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| LOE ID: | 56142 | ||||
| Pollutant: | Enterococcus | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 75 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Not Specified | ||||
| Data Used to Assess Water Quality: | Zero of the 75 geomeans exceeded the enterococcus objective. | ||||
| Data Reference: | Data for Region 3 Beach Watch. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | California Ocean Plan (SWRCB 2005) states that the geometric mean for Enterococcus shall not exceed 35 MPN/100 mL. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at station Gazos Creek Access. | ||||
| Temporal Representation: | The samples were collected approximately once a week from January 2007 to August 2010. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | The samples were collected for the Beach Watch program. | ||||
| QAPP Information Reference(s): | |||||
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| LOE ID: | 217960 | ||||
| Pollutant: | Enterococcus | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 89 | ||||
| Number of Exceedances: | 10 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed data for Pacific Ocean at Gazos Creek Beach to determine beneficial use support and the results are as follows: 10 of the 89 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: | Data file of Region 3 Beachwatch Data. Includes data from all coastal counties in Region 3 including: , Santa Barbara, Santa Cruz, San Luis Obispo, Monterey, Ventura, and San Mateo counties. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | California Ocean Plan (SWRCB 2019) states that the bacteria water quality objective to protect the REC-1 beneficial for all ocean waters for Enterococci is a statistical value threshold (STV) of 110 cfu/100 mL. The STV shall not be exceeded by more than 10 percent of the samples collected in a calendar month, calculated in a static manner. | ||||
| Objective/Criterion Reference: | SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019 | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site(s), station(s): Gazos Creek Access | ||||
| Temporal Representation: | The samples were collected between the days of 2010-09-07 and 2019-06-10 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | QAPP for 2020 San Mateo County Beachwatch data. | ||||
| QAPP Information Reference(s): | QAPP for San Mateo County Beachwatch data for the 2020 Integrated Report. | ||||
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| LOE ID: | 217948 | ||||
| Pollutant: | Enterococcus | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 308 | ||||
| Number of Exceedances: | 19 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed data for Pacific Ocean at Gazos Creek Beach to determine beneficial use support and the results are as follows: 19 of the 308 samples exceeded the geomean water quality threshold for Enterococcus. This is a six week rolling geomean that is calculated weekly. | ||||
| Data Reference: | Data file of Region 3 Beachwatch Data. Includes data from all coastal counties in Region 3 including: , Santa Barbara, Santa Cruz, San Luis Obispo, Monterey, Ventura, and San Mateo counties. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | California Ocean Plan (SWRCB 2019) states that the bacteria water quality objective to protect the REC-1 beneficial for all ocean waters for Enterococci is a geometric mean (GM) of 30 cfu/100 mL. The waterbody GM shall not be greater that the GM magnitude in any six-week interval, calculated weekly. | ||||
| Objective/Criterion Reference: | SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019 | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site(s), station(s): Gazos Creek Access | ||||
| Temporal Representation: | The samples were collected between the days of 2010-09-07 and 2019-06-10 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | QAPP for 2020 San Mateo County Beachwatch data. | ||||
| QAPP Information Reference(s): | QAPP for San Mateo County Beachwatch data for the 2020 Integrated Report. | ||||
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| LOE ID: | 56141 | ||||
| Pollutant: | Enterococcus | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 111 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Beach Watch Program data that is collected by each County's Environmental Health Department for Pacific Ocean at Gazos Creek Beach to determine beneficial use support and results are as follows: 1 of 111 samples exceed the criterion for Enterococci. | ||||
| Data Reference: | Data for Region 3 Beach Watch. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | California Ocean Plan (SWRCB 2005) single sample maximum for enterococcus density shall not exceed 104 per 100 mL. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Data for this line of evidence for Pacific Ocean at Gazos Creek Beach was collected at 1 monitoring site [ Gazos Creek Access] | ||||
| Temporal Representation: | Data was collected over the time period 1/8/2007-8/30/2010. | ||||
| Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data. | ||||
| QAPP Information: | Water Board staff assessed Beach Watch Program data that is collected by each County's Environmental Health Department. There is no QA Project Plan but instead each County follows their own Quality Assurance Procedures | ||||
| QAPP Information Reference(s): | |||||
DECISION ID |
129346 |
Region 3 |
Pacific Ocean at Gazos Creek Beach |
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| Pollutant: | Fecal Coliform |
| 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)(2018) |
| Revision Status | Revised |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. |
| Regional Board 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded. |
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| LOE ID: | 217949 | ||||
| Pollutant: | Fecal Coliform | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 1 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed data for Pacific Ocean at Gazos Creek Beach to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a Single Sample Maximum (SSM) value that is calculated daily. | ||||
| Data Reference: | Data file of Region 3 Beachwatch Data. Includes data from all coastal counties in Region 3 including: , Santa Barbara, Santa Cruz, San Luis Obispo, Monterey, Ventura, and San Mateo counties. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | California Ocean Plan (SWRCB 2019) states that the Single Sample Maximum fecal coliform density not exceed 400 per 100 mL. | ||||
| Objective/Criterion Reference: | SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019 | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site(s), station(s): Gazos Creek Access | ||||
| Temporal Representation: | The samples were collected between the days of 2015-09-14 and 2015-09-14 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | QAPP for 2020 San Mateo County Beachwatch data. | ||||
| QAPP Information Reference(s): | QAPP for San Mateo County Beachwatch data for the 2020 Integrated Report. | ||||
DECISION ID |
80309 |
Region 3 |
Pacific Ocean at Gazos Creek Beach |
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| Pollutant: | Total Coliform |
| 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)(2016) |
| Revision Status | Original |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the section 303(d) list under sections 3.2 and 3.3 of the Listing Policy. Under these sections, 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. 11 of 112 samples exceeded the total coliform objective for shellfishing. 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. 11 of 112 samples exceeded the total coliform objective for shellfishing 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 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. |
| 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: | 56145 | ||||
| Pollutant: | Total Coliform | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Shellfish Harvesting | ||||
| Number of Samples: | 112 | ||||
| Number of Exceedances: | 11 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Beach Watch data for Pacific Ocean at Gazos Creek Beach to determine beneficial use support and results are as follows: 11 of 112 samples exceed the criterion for Coliform, Total. | ||||
| Data Reference: | Data for Region 3 Beach Watch. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The California Ocean Plan (2009) states the following: At all areas where shellfish may be harvested for human consumption, the following bacterial objectives shall be maintained throughout the water column: Ten percent of the samples collected during any 30-day period shall not exceed 230 MPN/100mL. | ||||
| Objective/Criterion Reference: | California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009 | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Data for this line of evidence for Pacific Ocean at Gazos Creek Beach was collected at 1 monitoring site [ Gazos Creek Access] | ||||
| Temporal Representation: | Data was collected over the time period 1/8/2007-8/30/2010. | ||||
| Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data. | ||||
| QAPP Information: | The samples were collected for the Beach Watch program. | ||||
| QAPP Information Reference(s): | |||||