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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name:	San Dieguito River
Water Body ID:	CAR9051100020080825090830
Water Body Type:	River & Stream


DECISION ID	17906

Pollutant:	Benthic Community Effects
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:	Pollution

Weight of Evidence:	Benthic Community Effects is being considered for placement on the section 303(d) list under sections 3.9 and 3.2 of the Listing Policy. Under section 3.9, an additional line of evidence associating the Benthic Community Effects with a water or sediment concentration of pollutants is necessary to assess listing status. One line of evidence is available in the administrative record to assess this indicator. 10 of 10 samples exceeded the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this water segment 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. 10 of 10 samples exceeded the Index of Biological Integrity (IBI) value of "poor" water quality for this area and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy, however as required under section 3.9 of the Listing Policy, pollutant(s) could not be directly associated with the Benthic Community Effects. 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 17906


LOE ID:	27026

Pollutant:	Benthic Community Effects
LOE Subgroup:	Adverse Biological Responses
Matrix:	Water
Fraction:	None

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	10
Number of Exceedances:	10

Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Ten samples of IBI data were taken from October 2002 to May 2007 at one sampling site. Of the total number of samples, all ten of the samples exceeded the IBI impairment threshold.
Data Reference:	Stream Bioassessment Data. Co-permitee Data. Collected 2002-2007.

Water Quality Objective/Criterion:	From the San Diego Basin Plan the objective is: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board.
Objective/Criterion Reference:	Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:	The Index of Biological Integrity (IBI) is an analytical tool that can be used to assess the biological and physical condition of streams and rivers within a zero to one hundred scoring range: Very Poor 0-19, Poor 20-39, Fair 40-59, Good 60- 79, Very Good 80-100. The IBI score of 39 was set as an impairment threshold because it is a statistical criterion of two standard deviations below the mean reference site score which defines the boundary between 'fair' and 'poor' IBI creek conditions. (Ode, p. 9)
Guideline Reference:	"A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams". Environmental Management. Volume 35, number 1 (2005): 1-13.

Spatial Representation:	Samples were collected at one site: SD-DDH on San Dieguito Creek.
Temporal Representation:	Sampling occurred during May and October annually over a four year period from May 2003 to October 2006 and during October 2002 and May 2007.
Environmental Conditions:
QAPP Information:	Quality Control for collection and identification was conducted in accordance with the Quality Assurance Manual for Freshwater Bioassessment.
QAPP Information Reference(s):	QUALITY ASSURANCE MANUAL FOR FRESHWATER BIOASSESSMENT Revision 0


DECISION ID	17059

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:	Nonpoint Source \| 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 3.2 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. Fifteen of 15 of the 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.Fifteen of 15 of the 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 17059


LOE ID:	7311

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

Beneficial Use:	Water Contact Recreation

Number of Samples:	15
Number of Exceedances:	15

Data and Information Type:	PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality:	All fifteen samples collected exceed the water quality objective according to the San Diego County Municipal Copermittees Urban Runoff Monitoring Report, January 2007. Samples were collected one to three times a year from 2001 to 2006.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	From the Basin Plan, the 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:	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 behind the Morgan Run Golf Course maintenance shop along a natural channel off Via De La Valle.
Temporal Representation:	Samples were collected one to three times a year from 2001-2006.
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	17060

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:	Nonpoint Source \| 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 3.2 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. Eight of 15 of the 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. Eight of 15 of the 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 17060


LOE ID:	7371

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

Beneficial Use:	Water Contact Recreation

Number of Samples:	15
Number of Exceedances:	8

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

Water Quality Objective/Criterion:	From the Basin Plan, no more than 10% of the samples during any 30-day period for waters designated for contact recreation shall exceed 400 per 100 ml (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 behind the Morgan Run Golf Course maintenance shop along a natural channel off Via De La Valle.
Temporal Representation:	Samples were collected one to three times a year from 2001-2006.
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	17055

Pollutant:	Nitrogen
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Nonpoint Source \| 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 3.2 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. Thirteen of 15 of the samples exceed the Basin Plan water quality objective for total nitrogen. 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. Thirteen of 15 of the samples exceed the Basin Plan water quality objective for total nitrogen, 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 17055


LOE ID:	7324

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	15
Number of Exceedances:	13

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Thirteen of fifteen samples collected exceed the water quality objective according to results in the San Diego County Municipal Copermittees Urban Runoff Monitoring Report, 2007. Samples were collected one to four times a year from 2001 through 2006.
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. 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 behind the Morgan Run Golf Course maintenance shop along a natural channel off Via De La Valle.
Temporal Representation:	Samples were collected one to four times a year from 2001-2006.
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:	7373

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	4
Number of Exceedances:	3

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Three of four samples collected exceed the water quality objective according to results in the Surface Water Ambient Monitoring Program, 2007. Samples were collected on January 16, April 17, May 15 and September 9, 2003.
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. 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 monitoring station San Dieguito 9 (station id: 905SDSDQ9 lat/long: 32.97877/-117.23506), located on the main stem of the San Dieguito River.
Temporal Representation:	Samples were collected on January 16, April 17, May 15 and September 9, 2003.
Environmental Conditions:	The above sampling events occurred during wet weather between storm events, wet weather high base flow, dry weather declining base flow, and dry weather 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	17052

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:	Nonpoint Source \| 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 3.2 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. Sixteen of 19 of the 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. Sixteen of 19 of the 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 17052


LOE ID:	7312

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	15
Number of Exceedances:	12

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Twelve of fifteen samples collected exceed the water quality objective according to results in the San Diego County Municipal Copermittees Urban Runoff Monitoring Report, 2007. Samples were collected one to four times a year from 2001-2006.
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. The Water Quality Control Plan goal for the San Diego Basin Goal is 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 behind the Morgan Run Golf Course maintenance shop along a natural channel off Via De La Valle.
Temporal Representation:	Samples were collected one to four times a year from 2001-2006.
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:	7372

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

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 exceed the water quality objective according to results in the Surface Water Ambient Monitoring Program Report, 2007. Samples were collected on January 16, April 17, May 15 and September 9, 2003.
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) Water Quality Control Plan for the San Diego Basin 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 monitoring station San Dieguito 9 (station id: 905SDSDQ9 lat/long: 32.97877/-117.23506), located on the main stem of the San Dieguito River.
Temporal Representation:	Samples were collected on January 16, April 17, May 15 and September 9, 2003.
Environmental Conditions:	The above sampling events occurred during wet weather between storm events, wet weather high base flow, dry weather declining base flow, and dry weather 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	17054

Pollutant:	Total Dissolved Solids
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Nonpoint Source \| Point Source
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. Fifteen of 15 of the samples exceed the Basin Plan water quality objective for total dissolved solids. 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. Fifteen of 15 of the samples exceed the Basin Plan water quality objective for total dissolved solids, 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 17054


LOE ID:	7313

Pollutant:	Total Dissolved Solids
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	15
Number of Exceedances:	15

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	All fifteen samples collected exceed the water quality objective. Since a maximum of four samples were collected at most in a one year period, any exceedance results in an annual exceedance frequency greater than 10% according to the San Diego County Municipal Copermittees Urban Runoff Monitoring Report, 2007. Samples were collected one to three times a year from 2001 to 2006.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	From the Basin Plan, concentrations of total dissolved solids cannot exceed 500 mg/L. This concentration is not to be exceeded more than 10% of the time during any one year period (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 behind the Morgan Run Golf Course maintenance shop along a natural channel off Via De La Valle.
Temporal Representation:	Samples were collected one to three times a year from 2001-2006.
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	17058

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
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 are available in the administrative record to assess this pollutant. Thirteen of the 19 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. Thirteen of the 19 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 17058


LOE ID:	24991

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	4
Number of Exceedances:	4

Data and Information Type:	Ambient toxicity testing (chronic)
Data Used to Assess Water Quality:	Selenastrum capricornutum- (used for the 303(d) Listing) three samples were collected and three samples show significant toxicity levels (SL) and Compliant with QAPP as determined by the Selenastrum capricornutum growth test. Other Toxicity Tests: Ceriodaphnia dubia- Four samples were collected and two samples show significant toxicity levels (SL) as determined by the Ceriodaphnia dubia survival/reproductive test. Hyalella azteca- Two samples were collected and neithered show significant toxicity levels (SL) as determined by the Hyalella azteca growth and survival test according to results in the Surface Water Ambient Monitoring Program Annual Progress Report, 2007. Samples were collected in January, April, May and September 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 San Dieguito 9 (station id: 905SDSDQ9 lat/long: 32.97877/-117.23506), located on the main stem of the San Dieguito River.
Temporal Representation:	Samples were collected in January, April, May and September 2003.
Environmental Conditions:
QAPP Information:	QA/QC conducted in accordance with the Surface 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:	7492

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	15
Number of Exceedances:	9

Data and Information Type:	Ambient toxicity testing (chronic)
Data Used to Assess Water Quality:	Ceriodaphnia dubia- Six of fifteen samples collected were found to be toxic as determined by the Ceriodaphnia dubia survival/reproductive test. Hyalella azteca- None of the fifteen samples collected were found to be toxic as determined by the Hyalella azteca survival test. Selenastrum capricornutum- Five of fifteen samples collected were found to be toxic as determined by the Selenastrum capricornutum growth test.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.
	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013

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:	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.
Guideline Reference:	Waste Discharge Requirements for Discharges of Urban Runoff From the Municipal Separate Storm Sewer Systems Draining the Watersheds of the County of San Diego, the Incorporated Cities of San Diego, the San Diego Unified Port District, and the San Diego County Regional Airport. Order No. R9-2007-0001.

Spatial Representation:	Samples were collected at the mass loading station located near the lower boundary of the watershed behind the Morgan Run Golf Course maintenance shop along a natural channel off Via De La Valle.
Temporal Representation:	Samples were collected one to four times a year from 2001-2006.
Environmental Conditions:	Samples were collected during wet weather.
QAPP Information:	QA/QC conducted according to Weston Solutions quality assurance plan.
QAPP Information Reference(s):	Weston Solutions, 2004. Quality Management Manual. March 2004.