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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name:	Pacific Ocean at Twin Lakes Beach (Santa Cruz County)
Water Body ID:	CAX3041205320021002231123
Water Body Type:	Coastal & Bay Shoreline


DECISION ID	12259

Pollutant:	Enterococcus
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This water segment-pollutant combination is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this water segment-pollutant combination. Water Board staff assessed one data set against two different evaluation criteria (i.e. single sample maximum and geomean). Two of 109 samples exceeded the single sample maximum criterion and zero of 26 geomean assessments exceeded the geomean criterion. 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. Two of 109 samples exceeded the single sample maximum criterion and zero of 26 geomean assessments exceeded the geomean criterion 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.

RWQCB Board Decision / Staff 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.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12259


LOE ID:	20092

Pollutant:	Enterococcus
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Water Contact Recreation

Number of Samples:	109
Number of Exceedances:	2

Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed data for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 2 of 109 samples exceed the criterion for Enterococci.
Data Reference:	AB 411 Data for 2004
	AB 411 Data for 2005
	AB 411 Data for 2006

Water Quality Objective/Criterion:	California Ocean Plan (SWRCB 2005) states that the single sample maximum for Enterococcus shall not exceed 104 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:	Data for this line of evidence for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) was collected at one AB411 monitoring site (Twin Lakes Beach)
Temporal Representation:	Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information:	QA information not available
QAPP Information Reference(s):


LOE ID:	20091

Pollutant:	Enterococcus
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Water Contact Recreation

Number of Samples:	26
Number of Exceedances:	0

Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed data for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 26 samples exceed the criterion for Enterococci.
Data Reference:	AB 411 Data for 2004
	AB 411 Data for 2005
	AB 411 Data for 2006

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:	Data for this line of evidence for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) was collected at one AB411 monitoring site (Twin Lakes Beach)
Temporal Representation:	Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information:	QA information not available
QAPP Information Reference(s):


DECISION ID	12258

Pollutant:	Escherichia coli (E. Coli)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This water segment-pollutant combination is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this water segment-pollutant combination. Zero of seven samples exceeded the single sample maximum criterion and zero of two geomean assessments exceeded the geomean criterion. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 26 samples to make a "use rating" decision of Fully Supporting. 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. Zero of seven samples exceeded the single sample maximum criterion and zero of two geomean assessments exceeded the geomean criterion 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.

RWQCB Board Decision / Staff 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.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12258


LOE ID:	20093

Pollutant:	Escherichia coli (E. Coli)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Water Contact Recreation

Number of Samples:	2
Number of Exceedances:	0

Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed data for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Escherichia coli.
Data Reference:	AB 411 Data for 2004
	AB 411 Data for 2005
	AB 411 Data for 2006

Water Quality Objective/Criterion:	USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Evaluation Guideline:	Steady State Geometric Mean Indicator Density is 126 MPN/100mL (as stated in Table 4, Page 15).
Guideline Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:	Data for this line of evidence for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) was collected at one AB411 monitoring site (Twin Lakes Beach)
Temporal Representation:	Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information:	QA information not available
QAPP Information Reference(s):


LOE ID:	20094

Pollutant:	Escherichia coli (E. Coli)
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:	Central Coast Regional Board Staff assessed data for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Escherichia coli.
Data Reference:	AB 411 Data for 2004
	AB 411 Data for 2005
	AB 411 Data for 2006

Water Quality Objective/Criterion:	USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Evaluation Guideline:	Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL (as stated in Table 4, page 15)
Guideline Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:	Data for this line of evidence for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) was collected at one AB411 monitoring site (Twin Lakes Beach)
Temporal Representation:	Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information:	QA information not available
QAPP Information Reference(s):


DECISION ID	14712

Pollutant:	Fecal Coliform
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This water segment-pollutant combination is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this water segment-pollutant combination. One of 86 samples exceeded the single sample maximum criterion and zero of 21 geomean assessments exceeded the geomean criterion. 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. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 26 samples to make a "use rating" decision of Fully Supporting. 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. One of 86 samples exceeded the single sample maximum criterion and zero of 21 geomean assessments exceeded the geomean criterion. Neither of these 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.

RWQCB Board Decision / Staff 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.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 14712


LOE ID:	20074

Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Water Contact Recreation

Number of Samples:	86
Number of Exceedances:	1

Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed data for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 1 of 86 samples exceed the criterion for Coliform, Fecal.
Data Reference:	AB 411 Data for 2004
	AB 411 Data for 2005
	AB 411 Data for 2006

Water Quality Objective/Criterion:	California Ocean Plan (SWRCB 2005) states that the single sample maximum for fecal coliform shall not exceed 400 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:	Data for this line of evidence for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) was collected at one AB411 monitoring site (Twin Lakes Beach)
Temporal Representation:	Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information:	QA information not available
QAPP Information Reference(s):


LOE ID:	20073

Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Water Contact Recreation

Number of Samples:	21
Number of Exceedances:	0

Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed data for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Coliform, Fecal.
Data Reference:	AB 411 Data for 2004
	AB 411 Data for 2005
	AB 411 Data for 2006

Water Quality Objective/Criterion:	California Ocean Plan (SWRCB 2005) states that the 30-day geometric mean for fecal coliform shall not exceed 200 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:	Data for this line of evidence for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) was collected at one AB411 monitoring site (Twin Lakes Beach)
Temporal Representation:	Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information:	QA information not available
QAPP Information Reference(s):


DECISION ID	12272

Pollutant:	Total Coliform
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This water segment-pollutant combination is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this water segment-pollutant combination. Water Board staff assessed one data set against three different evaluation criteria (i.e. single sample maximum, geomean, and total to fecal ratio.). Zero of 109 samples exceeded the single sample maximum criterion, zero of 26 geomean assessments exceeded the geomean criterion, and one of 86 sample ratio exceeded the total to fecal ratio criterion. 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. Zero of 109 samples exceeded the single sample maximum criterion, zero of 26 geomean assessments exceeded the geomean criterion, and one of 86 sample ratio exceeded the total to fecal ratio criterion 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.

RWQCB Board Decision / Staff 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.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12272


LOE ID:	20095

Pollutant:	Total Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Water Contact Recreation

Number of Samples:	109
Number of Exceedances:	0

Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed data for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 109 samples exceed the criterion for Coliform, Total.
Data Reference:	AB 411 Data for 2004
	AB 411 Data for 2005
	AB 411 Data for 2006

Water Quality Objective/Criterion:	California Ocean Plan (2005) single sample maximum states that total coliform density shall not exceed 10,000 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:	Data for this line of evidence for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) was collected at one monitoring site (Twin Lakes Beach)
Temporal Representation:	Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information:	QA information not available
QAPP Information Reference(s):


LOE ID:	20096

Pollutant:	Total Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Water Contact Recreation

Number of Samples:	26
Number of Exceedances:	0

Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed data for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 26 samples exceed the criterion for Coliform, Total.
Data Reference:	AB 411 Data for 2004
	AB 411 Data for 2005
	AB 411 Data for 2006

Water Quality Objective/Criterion:	California Ocean Plan (2005) 30-day geometric mean standard for total coliform states that total coliform density shall not exceed 1,000 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:	Data for this line of evidence for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) was collected at one monitoring site (Twin Lakes Beach)
Temporal Representation:	Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information:	QA information not available
QAPP Information Reference(s):


LOE ID:	20097

Pollutant:	Total Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Water Contact Recreation

Number of Samples:	86
Number of Exceedances:	1

Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed data for Pacific Ocean at Twin Lakes Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 1 of 86 samples exceed the criterion for Coliform, Total.
Data Reference:	AB 411 Data for 2004
	AB 411 Data for 2005
	AB 411 Data for 2006

Water Quality Objective/Criterion:	California Ocean Plan (2005) single sample maximum standard for total coliform states that total coliform density shall not exceed 1,000 MPN/100 mL when the fecal coliform/total coliform ratio exceeds 0.1.
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 Twin Lakes Beach (Santa Cruz County) was collected at one monitoring site (Twin Lakes Beach)
Temporal Representation:	Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information:	QA information not available
QAPP Information Reference(s):