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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name:	Santa Margarita River (Upper)
Water Body ID:	CAR9022200020011001141050
Water Body Type:	River & Stream


DECISION ID	5966

Pollutant:	Phosphorus
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)(2006)
Revision Status	Revised
Sources:	Unknown Nonpoint Source \| Unknown Point Source \| Urban Runoff/Storm Sewers
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.

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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 5966


LOE ID:	7407

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	4
Number of Exceedances:	4

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	All four samples collected exceeded the total phosphorus water quality objective. Samples were collected between January 2003 and September 2003 for the SWAMP program.
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.
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:	Water Quality Control Plan for the San Diego Basin Goal of 0.1 mg/L for total phosphorus in streams and other flowing waters.
Guideline Reference:	Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	One sampling site was used in this line of evidence. Santa Margarita 1 (902SMSMR1 lat/long: 33.47404/-117.14148).
Temporal Representation:	Samples were collected on January 2003, April 2003, May 2003, and September 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:	Puckett, M. 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program ("SWAMP"). California Department of Fish and Game, Monterey, CA.
QAPP Information Reference(s):


LOE ID:	4731

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	0
Number of Exceedances:	0

Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference:	Placeholder reference pre-2006 303(d)

Water Quality Objective/Criterion:	Unspecified
Objective/Criterion Reference:	Placeholder reference pre-2006 303(d)

Evaluation Guideline:	Unspecified
Guideline Reference:	Placeholder reference pre-2006 303(d)

Spatial Representation:	Unspecified
Temporal Representation:	Unspecified
Environmental Conditions:	Unspecified
QAPP Information:	Unspecified
QAPP Information Reference(s):


DECISION ID	17015

Pollutant:	Alkalinity, Carbonate as CaCO3 \| Ammonia \| Manganese \| Nickel \| Orthophosphate \| Total Kjeldahl Nitrogen (TKN) \| Total Suspended Solids (TSS)
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:	These pollutants are being considered for placement on the section 303(d) list under sections 3.1 and 3.2 of the Listing Policy. Under sections 3.1 and 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. None of the samples exceed the water quality objectives for these multiple pollutants. 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 the samples exceed the water quality objectives for these multiple pollutants 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 17015


LOE ID:	26402

Pollutant:	Alkalinity, Carbonate as CaCO3 \| Ammonia \| Manganese \| Nickel \| Orthophosphate \| Total Kjeldahl Nitrogen (TKN) \| Total Suspended Solids (TSS)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	37
Number of Exceedances:	0

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	37 samples were collected at Santa Margarita Creek station 902SMSMR1 during the months of January 2003, April 2003, May 2003, and September 2003, for conventioanl inorganics analyses. None of the 37 samples showed excessive concentrations.
Data Reference:	Monitoring data for Region 9

Water Quality Objective/Criterion:	Alkalinity as CaCO3 20 mg/l, ammonia as N 0.025 mg/l, nitrite as N 1.mg/l, nitrogen total Kjeldahl (If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used), ortho phosphate as P total 0.05 mg/l, sulfate 250 mg/l, total suspended solids narrative: Waters shall not contain suspended solids in concentrations of solids that cause nuisance or adversely affect beneficial uses.
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:

Spatial Representation:	Water samples were collected at Santa Margarita Creek station 902SMSMR1; (Latitude 33.4741, Longitude -117.1414).
Temporal Representation:	Water samples were collected on January 2003, April 2003, May 2003, and September 2003.
Environmental Conditions:
QAPP Information:	Quality control for chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


DECISION ID	17016

Pollutant:	Metals
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. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objectives for the multiple metal pollutants. 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 the samples exceed the water quality objectives for the multiple metal pollutants 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 17016


LOE ID:	26399

Pollutant:	Metals
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	44
Number of Exceedances:	0

Data and Information Type:	Highest quality fixed-station P/C (conventional plus toxicants)
Data Used to Assess Water Quality:	Fouty-four samples were collected at Santa Margarita Creek station 902SMSMR1 during the months of January 2003, April 2003, May 2003, and September 2003, for metals analyses. None of the 44 samples show excessive concentrations.
Data Reference:	Monitoring data for Region 9

Water Quality Objective/Criterion:	The Maximum Contaminant Level (MCL) for aluminum is 1. mg /l (ppb). Water Quality Control for the San Diego Basin. 2007. The dissolved chronic criterion for the following metals applies: arsenic 150 µg/l (ppb), cadmium 2.2 µg/l (ppb), copper 9.0 µg/l (ppb), selenium 5.0 µg/l (ppb), zinc 120 µg/l (ppb), chromium 11 µg/l (ppb), manganese 0.05 mg/l, nickel 52 µg/l (ppb), lead 2.5 µg/l (ppb), and silver 3.4µg/l (ppb). California Toxics Rule. 2007.
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:

Spatial Representation:	Water samples were collected at Santa Margarita Creek station 902SMSMR1; (Latitude 33.4741, Longitude -117.1414).
Temporal Representation:	Water samples were collected on January 2003, April 2003, May 2003, and September 2003.
Environmental Conditions:
QAPP Information:	Quality control for chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


DECISION ID	17017

Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
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. One line of evidence is available in the administrative record to assess this pollutant. None of the 208 samples exceed the Basin Plan water quality objective for polycyclic aromatic hydrocarbons. 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 the 208 samples exceed the Basin Plan water quality objective for polycyclic aromatic hydrocarbons 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 17017


LOE ID:	26400

Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	208
Number of Exceedances:	0

Data and Information Type:	Highest quality fixed-station P/C (conventional plus toxicants)
Data Used to Assess Water Quality:	208 samples were collected at Santa Margarita Creek station 902SMSMR1 during the months of January 2003, April 2003, May 2003, and September 2003, for PAHs analyses. None of the 208 samples showed excessive concentrations.
Data Reference:	Monitoring data for Region 9

Water Quality Objective/Criterion:	Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels (MCL 0.0002mg/l) specified in California Code of Regulations, Title 22, Table 64444-A of section 64444 (Organic Chemicals) which is incorporated by reference into this plan.
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:

Spatial Representation:	Water samples were collected at Santa Margarita Creek station 902SMSMR1; (Latitude 33.4741, Longitude -117.1414).
Temporal Representation:	Water samples were collected on January 2003, April 2003, May 2003, and September 2003.
Environmental Conditions:
QAPP Information:	Quality control for chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


DECISION ID	17018

Pollutant:	PCBs (Polychlorinated biphenyls)
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. One line of evidence is available in the administrative record to assess this pollutant. None of the 208 samples exceed the Basin Plan water quality objective for polychlorinated biphenyls. 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 the 208 samples exceed the Basin Plan water quality objective for polychlorinated biphenyls 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 17018


LOE ID:	26401

Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	208
Number of Exceedances:	0

Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	208 samples were collected at Santa Margarita Creek station 902SMSMR1 during the months of January 2003, April 2003, May 2003, and September 2003, for PCBs analyses. None of the 208 samples showed excessive concentrations.
Data Reference:	Monitoring data for Region 9

Water Quality Objective/Criterion:	From the Basin Plan; waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels (MCL 0.5 mg/l) specified in California Code of Regulations, Title 22, Table 64444-A of section 64444 (Organic Chemicals) which is incorporated by reference into this plan.
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:

Spatial Representation:	Water samples were collected at Santa Margarita Creek station 902SMSMR1; (Latitude 33.4741, Longitude -117.1414).
Temporal Representation:	Water samples were collected on January 2003, April 2003, May 2003, and September 2003.
Environmental Conditions:
QAPP Information:	Quality control for chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


DECISION ID	17019

Pollutant:	Total Nitrogen as N
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 four 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 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 four samples exceed the Basin Plan water quality objective for total nitrogen as N and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of five samples is needed for application of table 3.2. 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 it cannot be determined if applicable water quality standards are not being exceeded.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 17019


LOE ID:	21194

Pollutant:	Total Nitrogen as N
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	4
Number of Exceedances:	2

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Two of the four samples collected at Santa Margarita River on January 2003, April 2003, May 2003, and September 2003 show excessive nitrogen concentrations. (SWAMP, 2007).
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. Water Quality Control Plan for the San Diego Basin Goal of 0.1 mg/L for total phosphorus in streams and other flowing waters.
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:	One sampling site was used in this line of evidence. Santa Margarita 1 (902SSMR1 lat/long: 33.47404/-117.14148).
Temporal Representation:	Samples were collected on January 2003, April 2003, May 2003, and September 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):	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	17020

Pollutant:	Toxicity
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Source Unknown \| Unknown Nonpoint Source \| Unknown Point 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 3.6 of the Listing Policy. Under section 3.6 a single line of evidence is necessary to assess listing status. Two lines of evidence is available in the administrative record to assess this pollutant. Five of the 12 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 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 12 samples exceed the water quality objective for toxicity and this exceeds 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 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 17020


LOE ID:	21402

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	4
Number of Exceedances:	2

Data and Information Type:	Ambient toxicity testing (chronic)
Data Used to Assess Water Quality:	Four samples were collected at Santa Margarita 1 station 902SSMR1 from January to September 2003, they showed significant toxicity levels (SL) in the following test: Selenastrum algae growth test - Two of the four samples. Ceriodaphnia dubia survival and reproduction. No toxicity was observed.
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.
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:	One sampling site was used in this line of evidence. Santa Margarita 1 (902SSMR1 lat/long: 33.47404/-117.14148).
Temporal Representation:	Samples were collected on the following dates: January 15, April 16, May 14, and September 9, 2003.
Environmental Conditions:
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):


LOE ID:	24978

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	6
Number of Exceedances:	3

Data and Information Type:	Ambient toxicity testing (chronic)
Data Used to Assess Water Quality:	Selenastrum capricornutum- Six samples were collected and none showed significant toxicity levels (SL) as determined by the Selenastrum capricornutum growth test. Ceriodaphnia dubia- Six samples were collected and two samples show significant toxicity levels (SL) as determined by the Ceriodaphnia dubia survival/reproductive. Hyalella azteca- Six samples were collected and one sample show significant toxicity levels (SL) as determined by the Hyalella azteca growth/survival test. Samples were collected November 2001 through February 2006.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.
	San Diego Stormwater Copermittees Jurisdiction Urban Runoff Managment Program. Final Report. Baseline Long Term Effectiveness Assessment.

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.
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:	Samples were found to exhibit toxicity when the No Observed Effect Concentration (NOEC) or median lethal concentration (LC50) for any given species was estimated to be less than 100% of the test sample concentration (U.S. EPA, 2002).
Guideline Reference:	Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Samples were collected at the monitoring stations Santa Margarita 1 located on the main stem of the Santa Margarita River.
Temporal Representation:	Samples were collected on the following dates: January 14-15, April 15-16, 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):


LOE ID:	30288

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:	Two samples were collected at Santa Margarita 1 station 902SSMR1 from January to September 2003, they showed significant toxicity levels (SL) in the following test: Hyalella azteca. No toxicity was observed.
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.
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:	One sampling site was used in this line of evidence. Santa Margarita 1 (902SSMR1 lat/long: 33.47404/-117.14148).
Temporal Representation:	Samples were collected on the following dates: January 15, April 16, May 14, and September 9, 2003.
Environmental Conditions:
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):