Draft California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 1 - North Coast Region

Water Body Name:	Big River Beach at Mendocino Bay
Water Body ID:	CAC1133004520081013235216
Water Body Type:	Coastal & Bay Shoreline


DECISION ID	79918	Region 1
Big River Beach at Mendocino Bay

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)(2016)
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2022
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Fecal indicator bacteria (which includes enterococcus, fecal coliform, and total coliform) are being considered for removal from the Section 303(d) list under Section 4.3 of the Listing Policy. Under this section a single line of evidence (LOE) is necessary to assess listing status. Five LOEs are available in the administrative record to assess indicator bacteria in this water body for the attainment of water contact recreation standards (REC-1). Additionally, one LOE is available to assess the attainment of shellfish harvesting (SHELL). Data from LOE 32797 were re-evaluated with LOE 133682. Data from LOE 44708 were re-evaluated with LOE 133603. LOE 25258 contained results for single sample maximum and geometric mean calculations, and those data were re-evaluated with LOEs 133724 and 133682, respectively. Data from LOEs 47634 and 47633 were re-evaluated with LOE 133664. LOEs 133599 and 133603 were not used in this assessment as they were evaluated at a 10% exceedance rate and contain the same data as LOEs 133682 and 133724, which were evaluated at a 4% exceedance rate. This pollutant was listed under section 4.3 of the Listing Policy utilizing a 4% exceedance rate and therefore a 4% exceedance rate is being utilized to consider if this water body should be de-listed. In the 2010 Integrated Report, the data results for single sample maximum and geometric mean calculations were presented in the same LOE. In the 2012 and 2018 Integrated Reports, the data results for single sample maximum and geometric mean calculations are presented in two separate LOEs. The following summary presents the total number of exceedances and total sample count from the two listing cycles combined in assessing REC-1: 1) 2 of 98 samples exceed the Statistical Threshold Value (STV) objective for enterococcus; 2) 0 of 307 samples exceed the geometric mean objective for enterococcus; 3) 0 of 163 samples exceed the singles sample maximum objective for fecal coliform; 4) 0 of 108 samples exceed the geometric mean objective for fecal coliform. For assessing SHELL beneficial use, 114 of 381 samples exceed the median concentration objective for total coliform. 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 as impaired for SHELL beneficial use; however, REC-1 beneficial use is fully supported. This conclusion is based on the staff findings that: (1) The data used satisfy the data quality requirements of Section 6.1.4 of the Policy. (2) The data used satisfy the data quantity requirements of Section 6.1.5 of the Policy. (3) Enterococcus and fecal coliform samples do not exceed the objectives more than the allowable frequency identified in Table 3.2 of the Listing Policy. (4) Total coliform samples related to the SHELL beneficial use exceed the median concentration objective more than the allowable frequency identified in Section 4.3 of the Listing Policy. (5) Pursuant to Section 4.11 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 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:

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

32797

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 94 geomeans exceeded the objective.

Data Reference:

Data for Region 1 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The geometric mean standard for entercoccus states that the entercoccus density shall not exceed 35 per 100 mL. Water Quality Control Plan for Ocean Waters 2009.

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Big River Beach at Mendocino Bay.

Temporal Representation:

Samples were collected approximately once a week from April to October 2007 to 2010.

Environmental Conditions:

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

133599

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

313

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Beachwatch_Mendocino County data for Big River Beach at Mendocino Bay to determine beneficial use support and the results are as follows: 0 of the 313 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): Big River

Temporal Representation:

The samples were collected between the days of 2003-01-14 and 2017-05-02 .

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.

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

133603

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

103

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Beachwatch_Mendocino County data for Big River Beach at Mendocino Bay to determine beneficial use support and the results are as follows: 2 of the 103 samples exceeded the Statistical Threshold Value (STV) water quality standard for Enterococcus. The STV is based on a 10% exceedance rate that is calculated monthly.

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 Statistical Threshold Value (STV) of 110 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).

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): Big River

Temporal Representation:

The samples were collected between the days of 2003-01-14 and 2017-05-02 .

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.

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

44708

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

107

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

1 of 107 samples exceed the criterion for Enterococci.

Data Reference:

Data for Region 1 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Ocean Plan (SWRCB 2009) states that the single sample maximum for Enterococcus shall not exceed 104 MPN/100 mL.

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 Big River Beach at Mendocino Bay was collected at 1 monitoring site [ Big River-Mendocino Bay]

Temporal Representation:

Data was collected over the time period 4/2/2007-8/24/2010.

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):

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

133682

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

307

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Beachwatch_Mendocino County data for Big River Beach at Mendocino Bay to determine beneficial use support and the results are as follows: 0 of the 307 samples exceeded the geomean water quality standard for Enterococcus. This is a six week rolling geomean that is calculated weekly. This data is for an AB411 beach. This LOE specifically corresponds with dry weather samples and only includes samples collected between April 1 and October 31 of each year.

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): Big River

Temporal Representation:

The samples were collected between the days of 2003-04-01 and 2017-05-02 .

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.

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

133724

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Beachwatch_Mendocino County data for Big River Beach at Mendocino Bay to determine beneficial use support and the results are as follows: 2 of the 98 samples exceeded the Statistical Threshold Value (STV) water quality standard for Enterococcus. The STV is based on a 10% exceedance rate that is calculated monthly. This data is for an AB411 beach. This LOE specifically corresponds with dry weather samples and only includes samples collected between April 1 and October 31 of each year.

Data Reference:

Mendocino County Beachwatch data reformatted and renamed to match CEDEN fields.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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): Big River

Temporal Representation:

The samples were collected between the days of 2003-04-01 and 2017-05-02 .

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.

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

47634

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

18 of 94 samples exceed the objective of 70 MPN/100mL applied as a rolling 30 day geomean for Total Coliform.

Data Reference:

Data for Region 1 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Ocean Plan states that at all areas where shellfish may be harvested for human consumption, the median total coliform density shall not exceed 70 per 100 mL. Staff applied the objective as a rolling 30 day geometric mean consistent with other state bacteria objectives and with guidance from the National Shellfish Sanitation Program from which the objectives were taken.

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 Big River Beach at Mendocino Bay was collected at 1 monitoring site [ Big River-Mendocino Bay]

Temporal Representation:

Data was collected over the time period 4/2/2007-8/24/2010.

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):

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

44570

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

107

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

0 of 107 samples exceed the criterion for Fecal Coliform.

Data Reference:

Data for Region 1 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Ocean Plan (SWRCB 2009) states that the single sample maximum for fecal coliform shall not exceed 400 MPN/100 mL

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 Big River Beach at Mendocino Bay was collected at 1 monitoring site [ Big River-Mendocino Bay]

Temporal Representation:

Data was collected over the time period 4/2/2007-8/24/2010.

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):

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

32799

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 94 geomeans exceeded the objective.

Data Reference:

Data for Region 1 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The geometric mean standard for fecal coliform states that the coliform density shall not exceed 200 MPN per 100 mL. Water Quality Control Plan for Ocean Waters (SWRCB 2009).

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at Big River Beach at Mendocino Bay.

Temporal Representation:

Samples were collected approximately once a week from April to October 2007 to 2010.

Environmental Conditions:

QAPP Information:

The samples were collected for the beach watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

25259

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

None of the 56 single samples of fecal coliform collected at Big River Beach at Mendocino Bay exceed the objective. Additionally, none of the 14 30-day geomean values exceed the objective. The single sample and geomean values are two different matrices used to analyzed the same data. Samples were collected by the Mendocino County Environmental Health Division in accordance with AB411 (Chapter 765, Statutes of 1997) requirements. Data is maintained by the State Water Board's Beach Watch program. Data is summarized by the North Coast Regional Water Board (North Coast RWQCB 2007).

Data Reference:

North Coast Beach Watch Data. Bacteria data collected by Del Norte County, Humboldt County, Mendocino County Environmental Health Division, Sonoma County Division of Environmental Health, and Marin County in accordance with AB411. Data managed by the State Water Resources Control Board's Beach Watch program at beachwatch.waterboards.ca.gov. Includes data from 2004 to 2006

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Ocean Plan (SWRCB 2005): The following bacterial objectives shall be maintained throughout the water column. The following standard is based on the 30-day geometric mean of the five most recent samples from each site: Fecal coliform density shall not exceed 200 MPN per 100 ml. The following standard is for the single sample maximum: Fecal coliform density shall not exceed 400 per 100ml. *Note: MPN is the most probable number of coliform units.

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:

Samples were collected at the Big River Beach at Mendocino Bay, which is part of the Big River-Mendocino Headlands State Park.

Temporal Representation:

Samples were collected weekly from April through October in 2005 and 2006.

Environmental Conditions:

Samples were collected during the dry season. Otherwise, there are no known environmental conditions (e.g., land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected and analyzed in accordance with the Sampling and Analysis Plan and the Laboratories and Laboratory Analyses procedures described in the "Draft Guidance for Salt Water Beaches" (DHS 2006).

QAPP Information Reference(s):

Draft Guidance for Salt Water Beaches. Last Update: April 10, 2006. Initial Draft: November 1997. Division of Drinking Water and Environmental Management, California Department of Health Services

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

133664

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Shellfish Harvesting

Number of Samples:

381

Number of Exceedances:

114

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Beachwatch_Mendocino County data for Big River Beach at Mendocino Bay to determine beneficial use support and the results are as follows: 114 of the 381 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): Big River

Temporal Representation:

The samples were collected between the days of 2003-01-14 and 2016-10-25 .

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.

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

47633

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Shellfish Harvesting

Number of Samples:

107

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

7 of 107 samples exceed the objective of 230 MPN/100mL applied as a single sample maximum for Total Coliform.

Data Reference:

Data for Region 1 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Ocean Plan 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 Big River Beach at Mendocino Bay was collected at 1 monitoring site [ Big River-Mendocino Bay]

Temporal Representation:

Data was collected over the time period 4/2/2007-8/24/2010.

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):

Line of Evidence (LOE) for Decision ID 79918, Indicator Bacteria	Region 1
Big River Beach at Mendocino Bay

LOE ID:

25258

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

None of the 56 single samples of enterococcus collected at Big River Beach at Mendocino Bay exceed the objective. Additionally, none of the 14 30-day geomean values exceed the objective. The single sample and geomean values are two different matrices used to analyzed the same data. Samples were collected by the Mendocino County Environmental Health Division in accordance with AB411 (Chapter 765, Statutes of 1997) requirements. Data is maintained by the State Water Board's Beach Watch program. Data is summarized by the North Coast Regional Water Board (North Coast RWQCB 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Ocean Plan (SWRCB 2005): The following bacterial objectives shall be maintained throughout the water column. The following standard is based on the 30-day geometric mean of the 5 most recent samples from each site: Enterococcus density shall not exceed 35 MPN per 100ml. The following standard is for the single sample maximum: Enterococcus density shall not exceed 104 per 100 ml. *Note: MPN is the most probable number of coliform units.

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:

Samples were collected at the Big River Beach at Mendocino Bay, which is part of the Big River-Mendocino Headlands State Park.

Temporal Representation:

Samples were collected weekly from April through October in 2005 and 2006.

Environmental Conditions:

Samples were collected during the dry season. Otherwise, there are no known environmental conditions (e.g., land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

QAPP Information Reference(s):

Draft Guidance for Salt Water Beaches. Last Update: April 10, 2006. Initial Draft: November 1997. Division of Drinking Water and Environmental Management, California Department of Health Services