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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name:	Santa Margarita River (Lower)
Water Body ID:	CAR9021100019980911161346
Water Body Type:	River & Stream


DECISION ID	17030

Pollutant:	Sulfates
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 pollutant is being considered for placement on the 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. One line of evidence is available in the administrative record to assess this pollutant. Two of the five samples exceed the Basin Plan water quality objective for sulfates. 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 the five samples exceed the Basin Plan water quality objective for sulfates 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 17030


LOE ID:	21195

Pollutant:	Sulfates
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	5
Number of Exceedances:	2

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Five water samples were collected at Santa Margarita River 10 Station 902SSMR10 on January 2003, April 2003, May 2003, and September 2003, Two of the five showed excessive sulfate concentrations according to results in California's Surface Water Ambient Monitoring Program Report, 2007.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	The recommended secondary drinking water standard for sulfate is 250 mg/l.
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Water samples were collected at Santa Margarita River 10 Station 902SSMR10; (Latitude 33.2370, Longitude -117.3923).
Temporal Representation:	Samples were collected on January 2003, April 2003, May 2003, and September 2003.
Environmental Conditions:	Samples were collected during wet weather.
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):	2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA.


DECISION ID	17025

Pollutant:	Toxicity
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 pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 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. One of the three of the samples exceed the water quality objective for toxicity. 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. One of the three of the samples exceed the water quality objective for toxicity. and this does not exceed the allowable frequency listed in Table 3.1 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 17025


LOE ID:	7501

Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	3
Number of Exceedances:	1

Data and Information Type:	Ambient toxicity testing (chronic)
Data Used to Assess Water Quality:	Selenastrum capricornutum- Three samples were collected with one samples showing significant toxicity levels (SL) as determined by the Selenastrum capricornutum growth test. Ceriodaphnia dubia- Two samples were collected and one samples show significant toxicity levels (SL) as determined by the Ceriodaphnia dubia survival/reproductive test. A fourth sample was collected and tested however the sample temperature was received outside acceptable limits upon laboratory receipt and the results were not used in this assessment. Hyalella azteca- Two samples were collected and one sample shows significant toxicity levels (SL) as determined by the Hyalella azteca growth/survival test according to results in the Surface Water Ambient Monitoring Program Report, 2007. Samples were collected on the following dates: January 14, April 15, May 13, and September 9, 2003.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.
	Monitoring data for Region 9

Water Quality Objective/Criterion:	From the Basin Plan, all waters shall be free of toxic substances that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (RWQCB, 2007).
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:	According to SWAMP, waters are considered toxic when samples show significant toxicity levels (SWAMP code SL) when compared to a negative control. Significant toxicity is determined when statistical tests result in an alpha of less than 5% and percent control values less than the evaluation threshold.
Guideline Reference:	Monitoring data for Region 9

Spatial Representation:	Samples were collected at the monitoring station Santa Margarita 10 located on the main stem of the Lower Santa Margarita River.
Temporal Representation:	Samples were collected on the following dates: January 14, April 15, May 13, and September 9, 2003.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study conducted in accordance with the California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):	2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA.


LOE ID:	30287

Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	2
Number of Exceedances:	0

Data and Information Type:	Ambient toxicity testing (chronic)
Data Used to Assess Water Quality:	Hyalella azteca- Two samples were collected and neither shows significant toxicity levels (SL) as determined by the Hyalella azteca growth/survival test according to results in the Surface Water Ambient Monitoring Program Report, 2007. Samples were collected on the following dates: January 14, April 15, May 13, and September 9, 2003.
Data Reference:	Monitoring data for Region 9

Water Quality Objective/Criterion:	From the Basin Plan, all waters shall be free of toxic substances that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (RWQCB, 2007).
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:	According to SWAMP, waters are considered toxic when samples show significant toxicity levels (SWAMP code SL) when compared to a negative control. Significant toxicity is determined when statistical tests result in an alpha of less than 5% and percent control values less than the evaluation threshold.
Guideline Reference:	Monitoring data for Region 9

Spatial Representation:	Samples were collected at the monitoring station Santa Margarita 10 located on the main stem of the Lower Santa Margarita River.
Temporal Representation:	Samples were collected on the following dates: January 14, April 15, May 13, and September 9, 2003.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study conducted in accordance with the California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):	2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA.


DECISION ID	17023

Pollutant:	Enterococcus
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Natural Sources \| Unknown Nonpoint Source \| Urban Runoff/Storm Sewers
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This pollutant is being considered for placement on the 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. One line of evidence is available in the administrative record to assess this pollutant. Five of the five samples exceed the Basin Plan water quality objective for enterococcus. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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. Five of the five samples exceed the Basin Plan water quality objective for enterococcus and this exceeds 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 17023


LOE ID:	7503

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

Beneficial Use:	Water Contact Recreation

Number of Samples:	5
Number of Exceedances:	5

Data and Information Type:	PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality:	All five samples collected exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected one to two times a year from 2001 - 2006, with the exception of the 2004-2005 monitoring year.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	From the Basin Plan, the bacteriological criteria for enterococcus sets a maximum limit at 61 colonies per 100mL (RWQCB, 2007).
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:

Spatial Representation:	Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.
Temporal Representation:	Samples were collected one to two times a year from 2001 - 2006, with the exception of the 2004-2005 monitoring year.
Environmental Conditions:	Samples were collected during wet weather.
QAPP Information:	QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.
QAPP Information Reference(s):


DECISION ID	17024

Pollutant:	Fecal Coliform
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Natural Sources \| Unknown Nonpoint Source \| Urban Runoff/Storm Sewers
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This pollutant is being considered for placement on the 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. One line of evidence is available in the administrative record to assess this pollutant. Five of the five samples exceed the Basin Plan water quality objective for fecal coliform. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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. Five of the five samples exceed the Basin Plan water quality objective for fecal coliform and this exceeds 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 17024


LOE ID:	7504

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

Beneficial Use:	Water Contact Recreation

Number of Samples:	5
Number of Exceedances:	5

Data and Information Type:	PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality:	All five samples collected exceed the water quality objective according to resuls in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected one to two times a year from 2001 - 2006, with the exception of the 2004-2005 monitoring year.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	No more than 10% of the samples during any 30-day period for waters designated for contact recreation shall exceed 400 colonies per 100 ml (RWQCB, 2007).
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.
Temporal Representation:	Samples were collected one to two times a year from 2001 - 2006, with the exception of the 2004-2005 monitoring year.
Environmental Conditions:	Samples were collected during wet weather.
QAPP Information:	QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.
QAPP Information Reference(s):


DECISION ID	17026

Pollutant:	Phosphorus
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Unknown Nonpoint Source \| Urban Runoff/Storm Sewers
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This pollutant is being considered for placement on the 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. Two lines of evidence are available in the administrative record to assess this pollutant. Ten of the eleven samples exceed the Basin Plan water quality objective for phosphorus. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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. Ten of the eleven samples exceed the Basin Plan water quality objective for phosphorus and this exceeds 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 17026


LOE ID:	7499

Pollutant:	Phosphorus
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	6
Number of Exceedances:	5

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Five of six samples exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	Water Quality Control Plan for the San Diego Basin has a goal of 0.1 mg/L for total phosphorus in streams and other flowing waters. (RWQCB, 2007)
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.
Temporal Representation:	Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.
Environmental Conditions:	Samples were collected during wet weather.
QAPP Information:	QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.
QAPP Information Reference(s):


LOE ID:	7500

Pollutant:	Phosphorus
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	5
Number of Exceedances:	5

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	All five samples exceed the water quality objective. according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected on the following dates: January 14, April 15, twice on May 13, and September 9, 2003.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses. Water Quality Control Plan for the San Diego Basin has a goal of 0.1 mg/L for total phosphorus in streams and other flowing waters. (RWQCB, 2007)
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	The sampling site lies on the lower Santa Margarita River (Santa Margarita 10 (902SSMR10 lat/long: 33.23669/-117.39175)).
Temporal Representation:	Samples were collected on the following dates: January 14, April 15, twice on May 13, and September 9, 2003.
Environmental Conditions:	The first two sampling events occurred between storm events and high base flow respectively. The third and fourth occurred during declining and minimum base flow respectively.
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


DECISION ID	17028

Pollutant:	Total Nitrogen as N
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Unknown Nonpoint Source \| Urban Runoff/Storm Sewers
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This pollutant is being considered for placement on the 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. Two lines of evidence are available in the administrative record to assess this pollutant. Eight of the eleven samples exceed the Basin Plan water quality objective for total nitrogen as N. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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. Eight of the eleven samples exceed the Basin Plan water quality objective for total nitrogen as N and this exceeds 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 17028


LOE ID:	7498

Pollutant:	Total Nitrogen as N
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	5
Number of Exceedances:	3

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Three of five samples exceed the water quality objective of 1.0 mg/L for total nitrogen according to results in the Surface Water Ambient Monitoring Program Report, 2007. Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.
Data Reference:	Monitoring data for Region 9

Water Quality Objective/Criterion:	Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses. (RWQCB, 2007) A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total P. These values are not to be exceeded more than 10% of the time unless studies of the specific water body in question clearly show that water quality objective changes are permissible and changes are approved by the Regional Board. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used. (RWQCB, 2007)
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.
Temporal Representation:	Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.
Environmental Conditions:	Samples were collected during wet weather.
QAPP Information:	QA/QC conducted according to Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):	2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA.


LOE ID:	7497

Pollutant:	Total Nitrogen as N
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	6
Number of Exceedances:	5

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Five of six samples exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected one to two times a year from 2001-2006 with the exception of the 2004-2005 monitoring year.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses. (RWQCB, 2007) A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total P. These values are not to be exceeded more than 10% of the time unless studies of the specific water body in question clearly show that water quality objective changes are permissible and changes are approved by the Regional Board. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used. (RWQCB, 2007)
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.
Temporal Representation:	Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.
Environmental Conditions:	Samples were collected during wet weather.
QAPP Information:	QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.
QAPP Information Reference(s):


DECISION ID	5872

Pollutant:	Mercury
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)(2006)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of 4 samples exceed the Basin Plan water quality objective for mercury. 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. None of 4 samples exceed the Basin Plan water quality objective for mercury and this does not exceed the allowable frequency listed in Table 3.1 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:	No new data were assessed for 2008. The Regional Board will update this decision when new data and information become available and are assessed.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 5872


LOE ID:	3012

Pollutant:	Mercury
LOE Subgroup:	Pollutant-Tissue
Matrix:	Tissue
Fraction:	Total

Beneficial Use:	Agricultural Supply

Number of Samples:	4
Number of Exceedances:	0

Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	None of 4 samples for mercury in fish tissue taken exceeded the screening value. (TSMP, 2002).
Data Reference:	Placeholder reference 2006 303(d)

Water Quality Objective/Criterion:	OEHHA screening value for mercury 0.3 mg/kg (ppm).
Objective/Criterion Reference:	Placeholder reference 2006 303(d)

Evaluation Guideline:
Guideline Reference:

Spatial Representation:	Lower Santa Margarita River.
Temporal Representation:	Samples were taken between March 1979 and August 1999.
Environmental Conditions:
QAPP Information:	CFCP 1998 Year 1 QA Summary Pesticides and PCBs. California Department of Fish and Game. CDFG Fish and Wildlife Water Pollution Control Laboratory Data Quality Assurance Report. 1999 Coastal Fish Contamination Program (CFCP Year 2). California Department of Fish and Game.
QAPP Information Reference(s):