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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name:	Sweetwater River
Water Body ID:	CAR9093100020011025105626
Water Body Type:	River & Stream


DECISION ID	16919

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. Fifteen of the 15 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 the 15 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 16919


LOE ID:	7184

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:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	All fifteen samples collected exceed the water quality objective for Enterococcus and thirteen of fifteen samples collected exceed the water quality objective for Fecal Coliform according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

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

Evaluation Guideline:
Guideline Reference:	Regional Water Quality Control Board, 2007. 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 in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge
Temporal Representation:	Samples were collected two to four times a year from 2002-2006.
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	16920

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 \| Source Unknown \| 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. Thirteen of the 13 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. Thirteen of the 13 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 16920


LOE ID:	7376

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

Beneficial Use:	Water Contact Recreation

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 Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
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. From the Basin Plan, no more than 10% of the samples for waters designated for contact recreation shall exceed 400 per 100 ml (RWQCB, 2007)
Objective/Criterion Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Regional Water Quality Control Board, 2007. 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 in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge
Temporal Representation:	Samples were collected two to four times a year from 2002-2006.
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	16784

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
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. Four lines of evidence are available in the administrative record to assess this pollutant. Fifteen 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. Fifteen 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 16784


LOE ID:	27030

Pollutant:	Biodiversity impacts
LOE Subgroup:	Adverse Biological Responses
Matrix:	Water
Fraction:	None

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	18
Number of Exceedances:	18

Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Eighteen samples of IBI data were taken from May 2002 to May 2007 at two sampling sites. Of the total number of samples, all eighteen 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:	Regional Water Quality Control Board, 2007. 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 two sites: SR-94 and SR-WS on Sweetwater River.
Temporal Representation:	Sampling occurred during May and October annually over a four year period from May 2003 to October 2006 and during May 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


LOE ID:	26469

Pollutant:	Biodiversity impacts
LOE Subgroup:	Adverse Biological Responses
Matrix:	Water
Fraction:	None

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	30
Number of Exceedances:	19

Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Thirty samples of IBI data were taken from May 1998 to 2007 at eight sampling sites. Of the total number of samples, nineteen of the samples exceeded the IBI impairment threshold.
Data Reference:	Fish and Game IBI Data
	Southern California Postfire Study 2007 IBIScores

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. (SDRWQCB, 1995)
Objective/Criterion Reference:	Regional Water Quality Control Board, 2007. 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 eight sites: 909SWR79x, 909SWR94x, 909SWRWSx, 909SWCSPD, 909SWCSPU, 909SWCSPx, 909WE0662, and 909SWRWWG on Sweetwater River.
Temporal Representation:	Sampling occurred during one to three events annually from May 1998 to 2007 except in 2003 and 2006.
Environmental Conditions:
QAPP Information:	Quality Control for collection and identification was conducted in accordance with the Quality Assurance Project Plan for the California Stream Bioassessment Procedure and the State of California, California Monitoring an Assessment Program: "CMAP", Quality Assurance Project Plan.
QAPP Information Reference(s):	State of California, California Monitoring and Assessment Program: "CMAP".
	Quality Assurance Project Plan for the California Stream Bioassessment Pocedure
	The San Diego Stream Team Quality Assurance Project Plan


LOE ID:	7377

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	4
Number of Exceedances:	0

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	None of the four samples collected exceed the water quality objective according to results in the Surface Water Ambient Monitoring Program Report, 2007. Samples were collected on June 1, 2005, September 7, 2005, January 31, 2006 and April 11, 2006.
Data Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program.

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:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Samples were collected from the monitoring station Sweetwater River 3 (station id: 909SSWR03 lat/long: 32.97877/-117.23506), located on the main stem of the Sweetwater River.
Temporal Representation:	Samples were collected on June 1, 2005, September 7, 2005, January 31, 2006 and April 11, 2006.
Environmental Conditions:	The above sampling events occurred during dry weather declining base flow, dry weather minimum base flow, wet weather between storm events, and wet weather high 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):


LOE ID:	7186

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

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 according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
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. (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:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Regional Water Quality Control Board, 2007. 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 in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge
Temporal Representation:	Samples were collected two to four times a year from 2002-2006.
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	16800

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:	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. Four lines of evidence are available in the administrative record to assess this pollutant. Fifteen of 28 of the samples exceed the water quality objective for chronic 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. Fifteen of 28 of the samples exceed the water quality objective for chronic 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 16800


LOE ID:	7506

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	15
Number of Exceedances:	8

Data and Information Type:	Ambient toxicity testing (chronic)
Data Used to Assess Water Quality:	Toxicity was observed in the following tests. Selenastrum capricornutum- Seven of fifteen samples collected were found to be toxic. Ceriodaphnia dubia survival and reproduction: Five of 15 tests were found to be toxic. Hyalella azteca; No samples were toxic. Data was collected by San Diego County for their urban runoff monitoring program.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

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:	Regional Water Quality Control Board, 2007. 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:	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

Spatial Representation:	Samples were collected from the Sweetwater River at Bonita Rd near Plaza Bonita.
Temporal Representation:	Samples were taken between February 2002 and February 2006.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance Weston's quality assurance plan.
QAPP Information Reference(s):	Weston Solutions, 2004. Quality Management Manual. March 2004.


LOE ID:	25673

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	8
Number of Exceedances:	6

Data and Information Type:	Ambient toxicity testing (chronic)
Data Used to Assess Water Quality:	Toxicity was observed in the following data from the Storm Water Ambient Monitoring Program Selenastrum capricornutum- Four of eight samples showed significant toxicity levels. Ceriodaphnia dubia; Two of eight samples were toxic.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.
	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program.

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:	Regional Water Quality Control Board, 2007. 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:	Surface Water Ambient Monitoring Program. 2007. Monitoring data for Region 9.

Spatial Representation:	Samples were collected from the monitoring station Sweetwater River 3 and 8 located on the main stem of the Sweetwater River.
Temporal Representation:	Samples were taken between May 2005 and April 2006.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


LOE ID:	30291

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	5
Number of Exceedances:	1

Data and Information Type:	Ambient toxicity testing (chronic)
Data Used to Assess Water Quality:	Toxicity was observed in the following data from the Storm Water Ambient Monitoring Program Hyalella azteca: One of five samples showed significant toxicity levels.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.
	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program.

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:	Regional Water Quality Control Board, 2007. 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:	Surface Water Ambient Monitoring Program. 2007. Monitoring data for Region 9.

Spatial Representation:	Samples were collected from the monitoring station Sweetwater River 3 and 8 located on the main stem of the Sweetwater River.
Temporal Representation:	Samples were taken between May 2005 and April 2006.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


LOE ID:	27030

Pollutant:	Biodiversity impacts
LOE Subgroup:	Adverse Biological Responses
Matrix:	Water
Fraction:	None

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	18
Number of Exceedances:	18

Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Eighteen samples of IBI data were taken from May 2002 to May 2007 at two sampling sites. Of the total number of samples, all eighteen 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:	Regional Water Quality Control Board, 2007. 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 two sites: SR-94 and SR-WS on Sweetwater River.
Temporal Representation:	Sampling occurred during May and October annually over a four year period from May 2003 to October 2006 and during May 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	16780

Pollutant:	Salinity/TDS/Chlorides
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Original
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 3.2 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. Eleven 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. Eleven 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 16780


LOE ID:	7185

Pollutant:	Total Dissolved Solids
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	15
Number of Exceedances:	11

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Eleven of 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 Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	From the Basin Plan, concentrations of total dissolved solids cannot exceed 1500 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:	Regional Water Quality Control Board, 2007. 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 in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge
Temporal Representation:	Samples were collected two to four times a year from 2002-2006.
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:	6519

Pollutant:	Sulfates
LOE Subgroup:	Pollution
Matrix:	Water
Fraction:	None

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	8
Number of Exceedances:	4

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Four of the eight samples collected at Sweetwater Rive show excessive sulfate concentrations according to results in California Surface Water Ambient Monitoring Program Report, 2007. Samples were collected in January 2003, April 2003, May 2003, and September 2003.
Data Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Water Quality Objective/Criterion:	The recommended secondary drinking water standard for sulfate is 250 mg/l (RWQCB, 2007).
Objective/Criterion Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:

Spatial Representation:	Water samples were collected at Sweetwater River Stations 909SSWR08.
Temporal Representation:	Samples were collected in January 2003, April 2003, May 2003, and September 2003.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


DECISION ID	16785

Pollutant:	Selenium
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Original
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 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Ten of 16 of the samples exceed the California Toxics Rule water quality objective for selenium. 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. California Toxics Rule water quality objective for selenium, 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 16785


LOE ID:	6518

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	8
Number of Exceedances:	5

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Five of the eight samples collected at Sweetwater River exceed the water quality objective of 5 µg/L for dissolved selenium according to results in California Surface Water Ambient Monitoring Program Report, 2007. Samples for Sweetwater River were collected in May 2005, September 2005, January 2006, and April 2006.
Data Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Water Quality Objective/Criterion:	CTR Freshwater Chronic (CCC) 5 ug/L. (U.S. EPA, 2000).
Objective/Criterion Reference:	Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants for the State of California; Rule. 40 CFR Part 131. U.S. Environmental Protection Agency, Region IX, Water Division, San Francisco, CA.

Evaluation Guideline:
Guideline Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Water samples were collected at Sweetwater River stations 909SSWR03.
Temporal Representation:	Samples for Sweetwater River were collected in May 2005, September 2005, January 2006, and April 2006.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


LOE ID:	25665

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

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	8
Number of Exceedances:	5

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Five of the eight samples collected at Sweetwater River exceed the water quality objective of 5 µg/L for dissolved selenium according to results in California Surface Water Ambient Monitoring Program Report, 2007. Samples for Sweetwater River were collected in May 2005, September 2005, January 2006, and April 2006.
Data Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Water Quality Objective/Criterion:	CTR Freshwater Chronic (CCC) 5 ug/L. (U.S. EPA, 2000).
Objective/Criterion Reference:	Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants for the State of California; Rule. 40 CFR Part 131. U.S. Environmental Protection Agency, Region IX, Water Division, San Francisco, CA.

Evaluation Guideline:
Guideline Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Water samples were collected at Sweetwater River stations 909SSWR08.
Temporal Representation:	Samples for Sweetwater River were collected in May 2005, September 2005, January 2006, and April 2006.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


DECISION ID	16782

Pollutant:	Sulfates
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Original
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 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Eight of 16 of the samples exceed the Basin Plan water quality objective for sulfate. 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 16 of the samples exceed the Basin Plan water quality objective for sulfate, 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 16782


LOE ID:	25667

Pollutant:	Sulfates
LOE Subgroup:	Pollution
Matrix:	Water
Fraction:	None

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	8
Number of Exceedances:	4

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Four of the eight samples collected at Sweetwater Rive show excessive sulfate concentrations according to results in California Surface Water Ambient Monitoring Program Report, 2007. Samples were collected in January 2003, April 2003, May 2003, and September 2003.
Data Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Water Quality Objective/Criterion:	The recommended secondary drinking water standard for sulfate is 250 mg/l (RWQCB, 2007).
Objective/Criterion Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:

Spatial Representation:	Water samples were collected at Sweetwater River Stations 909SSWR03.
Temporal Representation:	Samples were collected in January 2003, April 2003, May 2003, and September 2003.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


LOE ID:	7185

Pollutant:	Total Dissolved Solids
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	15
Number of Exceedances:	11

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Eleven of 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 Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
Data Reference:	Urban Runoff Monitoring, Volume 1- Final Report.

Water Quality Objective/Criterion:	From the Basin Plan, concentrations of total dissolved solids cannot exceed 1500 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:	Regional Water Quality Control Board, 2007. 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 in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge
Temporal Representation:	Samples were collected two to four times a year from 2002-2006.
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:	6519

Pollutant:	Sulfates
LOE Subgroup:	Pollution
Matrix:	Water
Fraction:	None

Beneficial Use:	Municipal & Domestic Supply

Number of Samples:	8
Number of Exceedances:	4

Data and Information Type:	Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality:	Four of the eight samples collected at Sweetwater Rive show excessive sulfate concentrations according to results in California Surface Water Ambient Monitoring Program Report, 2007. Samples were collected in January 2003, April 2003, May 2003, and September 2003.
Data Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Water Quality Objective/Criterion:	The recommended secondary drinking water standard for sulfate is 250 mg/l (RWQCB, 2007).
Objective/Criterion Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:

Spatial Representation:	Water samples were collected at Sweetwater River Stations 909SSWR08.
Temporal Representation:	Samples were collected in January 2003, April 2003, May 2003, and September 2003.
Environmental Conditions:
QAPP Information:	Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):


DECISION ID	16786

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	Original
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. Four lines of evidence are available in the administrative record to assess this pollutant. Fifteen of 19 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. Fifteen of 19 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 16786


LOE ID:	7190

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

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 Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
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. (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 phosphorus, 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:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Regional Water Quality Control Board, 2007. 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 in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge.
Temporal Representation:	Samples were collected two to four times a year from 2002-2006.
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:	7378

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 exceed the water quality objective according to results in the Surface Water Ambient Monitoring Program Report, 2007. Samples were collected on June 1 and September 7, 2005, January 31 and April 11, 2006.
Data Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program.

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 phosphorus, 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:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Evaluation Guideline:
Guideline Reference:	Regional Water Quality Control Board, 2007. Water Quality Control Plan for the San Diego Basin (9).

Spatial Representation:	Samples were collected from the monitoring station Sweetwater River 3 (station id: 909SSWR03 lat/long: 32.97877/-117.23506), located on the main stem of the Sweetwater River.
Temporal Representation:	Samples were collected on June 1 and September 7, 2005, January 31 and April 11, 2006.
Environmental Conditions:	The above sampling events occurred during dry weather declining base flow, dry weather minimum base flow, wet weather between storm events, and wet weather high 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):


LOE ID:	27030

Pollutant:	Biodiversity impacts
LOE Subgroup:	Adverse Biological Responses
Matrix:	Water
Fraction:	None

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	18
Number of Exceedances:	18

Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Eighteen samples of IBI data were taken from May 2002 to May 2007 at two sampling sites. Of the total number of samples, all eighteen 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:	Regional Water Quality Control Board, 2007. 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 two sites: SR-94 and SR-WS on Sweetwater River.
Temporal Representation:	Sampling occurred during May and October annually over a four year period from May 2003 to October 2006 and during May 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


LOE ID:	26469

Pollutant:	Biodiversity impacts
LOE Subgroup:	Adverse Biological Responses
Matrix:	Water
Fraction:	None

Beneficial Use:	Warm Freshwater Habitat

Number of Samples:	30
Number of Exceedances:	19

Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Thirty samples of IBI data were taken from May 1998 to 2007 at eight sampling sites. Of the total number of samples, nineteen of the samples exceeded the IBI impairment threshold.
Data Reference:	Fish and Game IBI Data
	Southern California Postfire Study 2007 IBIScores

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. (SDRWQCB, 1995)
Objective/Criterion Reference:	Regional Water Quality Control Board, 2007. 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 eight sites: 909SWR79x, 909SWR94x, 909SWRWSx, 909SWCSPD, 909SWCSPU, 909SWCSPx, 909WE0662, and 909SWRWWG on Sweetwater River.
Temporal Representation:	Sampling occurred during one to three events annually from May 1998 to 2007 except in 2003 and 2006.
Environmental Conditions:
QAPP Information:	Quality Control for collection and identification was conducted in accordance with the Quality Assurance Project Plan for the California Stream Bioassessment Procedure and the State of California, California Monitoring an Assessment Program: "CMAP", Quality Assurance Project Plan.
QAPP Information Reference(s):	State of California, California Monitoring and Assessment Program: "CMAP".
	Quality Assurance Project Plan for the California Stream Bioassessment Pocedure
	The San Diego Stream Team Quality Assurance Project Plan