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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name: Long Canyon Creek (tributary to Murrieta Creek)
Water Body ID: CAR9028300020011025112509
Water Body Type: River & Stream
 
DECISION ID
4781
 
Pollutant: Total Dissolved Solids
Final Listing Decision: Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2006)
Revision Status Revised
Reason for Delisting: Flaws in original listing
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 one line(s) of evidence are necessary to assess listing status.

No lines of evidence are available in the administrative record to assess this pollutant.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
 
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 the data used for the assessment was for Long Canyon Creek in the 911 watershed, not 902. The LOE and Decision have been moved to the Long Canyon Creek in the Cottonwood watershed.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 4781
 
LOE ID: 3164
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 25
Number of Exceedances: 6
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Data were collected by the City of San Diego Water Dept. in 1997 and 1998. Six of the 25 samples were in exceedance. All 6 samples were collected on 01/29/1998.
Data Reference: Placeholder reference 2006 303(d)
 
Water Quality Objective/Criterion: From the Basin Plan: For inland surface waters and all beneficial uses, the WQO for TDS is 500 mg/L. This concentration is not to be exceeded more than 10% of the time during any one year period.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at Long Canyon Creek site LCC2.
Temporal Representation: Samples were collected on 03/12/1997, 05/13/1997, 06/18/1997, and 01/29/1998. Five to nine of the samples were collected per day over a period of 3 minutes to 1.5 hours.
Environmental Conditions:
QAPP Information: Data used in 2002 assessment.
QAPP Information Reference(s):
 
DECISION ID
16699
 
Pollutant: Phosphorus
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Four of the 4 samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Four of the 4 samples exceeded the Basin Plan objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded due to limited samples.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16699
 
LOE ID: 6266
 
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 evaluation guideline according to results in the Riverside County Flood Control and Water Conservation District annual progress reports. Samples were collected on 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Data Reference: Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
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).
The Water Quality Control Plan for San Diego Basin Plan which has a goal of 0.1 mg/L for total phosphorus in streams and other flowing waters (RWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Spatial Representation: Samples were collected at station 780 Long Canyon Creek.
Lat/long: 33°30’38” N/117°09’40” W.
Temporal Representation: Samples were collected on 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Environmental Conditions: One sample represents the first storm event of each monitoring year that produces sufficient flow to collect a composite sample. In addition, another sample is collected during the monitoring year to represent a wet weather event.
QAPP Information: Quality assurance conducted according to the Riverside County's Consolidated Monitoring Plan.
QAPP Information Reference(s): Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
DECISION ID
16700
 
Pollutant: Total Nitrogen as N
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Four of the 4 samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Four of the 4 samples exceeded the Basin Plan objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded due to limited samples.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16700
 
LOE ID: 6265
 
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: 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 evaluation guideline of 1 mg/L according to results in the Riverside County Flood Control and Water Conservation District annual progress report from 2005 and 2006. Samples were collected on 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Data Reference: Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
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: 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 station 780 Long Canyon Creek.
Lat/long: 33°30’38” N/117°09’40” W.
Temporal Representation: Samples were collected on 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Environmental Conditions: One sample represents the first storm event of each monitoring year that produces sufficient flow to collect a composite sample. In addition, another sample is collected during the monitoring year to represent a wet weather event.
QAPP Information: Quality assurance conducted according to the Riverside County's Consolidated Monitoring Plan.
QAPP Information Reference(s): Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
DECISION ID
16520
 
Pollutant: Chlorpyrifos
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: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Three of the 4 samples exceed the water quality objective.

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. Three of the 4 samples exceed the Basin Plan objective for pesticides 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 16520
 
LOE ID: 6456
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
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 out of four samples exceeded 1-hour average concentration of Chlorpyrifos according to results in the Riverside County Flood Control and Water Conservation District's Watershed Annual Progress Report from 2005 and 2006. Samples were collected on 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Data Reference: Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in the water column, sediments or biota at concentration(s) that adversely affect beneficial uses. Pesticides shall not be present at levels which will bioaccumulate in aquatic organisms to levels which are harmful to human health, wildlife or aquatic organisms (RWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline: The 4-day average concentration of chlorpyrifos in freshwater is 0.014 ug/L. The 1-hour average concentration of chlorpyrifos in freshwater is 0.025 ug/L according to Siepmann and Finlayson, 2000; Finlayson, 2004.
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Spatial Representation: Samples were collected at station 780 on Long Canyon Creek. Lat/long: 33°30’38” N/117°09’40” W.
Temporal Representation: Samples were collected on the following dates: 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Environmental Conditions: One sample represents the first storm event of each monitoring year that produces sufficient flow to collect a composite sample. In addition, another sample is collected during the monitoring year to represent a wet weather event.
QAPP Information: Quality assurance conducted according to the Riverside County's Consolidated Monitoring Plan.
QAPP Information Reference(s): Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
DECISION ID
16559
 
Pollutant: Escherichia coli (E. Coli)
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: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 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. Four of the 4 samples exceed the water quality objective.

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. Four of the 4 samples exceed the Basin Plan objective for E. Coli 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 16559
 
LOE ID: 7150
 
Pollutant: Escherichia coli (E. Coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Water Contact Recreation
 
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 the results in the Riverside County Flood Control and Water Conservation District annual progress report from 2005 and 2006. Samples were collected on 10/20/04, 12/28/04, 10/18/05 and 2/27/06.
Data Reference: Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
Water Quality Objective/Criterion: The maximum E. coli level for moderately or lightly used areas is 406 colonies 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 Long Canyon Creek.
Lat/long: 33°30’38” N/117°09’40” W.
Temporal Representation: Samples were collected on 10/20/04, 12/28/04, 10/18/05 and 2/27/06.
Environmental Conditions: One sample represents the first storm event of each monitoring year that produces sufficient flow to collect a composite sample. In addition, another sample is collected during the monitoring year to represent a wet weather event.
QAPP Information: Quality assurance conducted according to the Riverside County's Consolidated Monitoring Plan.
QAPP Information Reference(s): Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
DECISION ID
16560
 
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: Source Unknown
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 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. Four of the 4 samples exceed the water quality objective.

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. Four of the 4 samples exceed the Basin Plan 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 16560
 
LOE ID: 7398
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
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 Riverside County Flood Control and Water Conservation District annual progress report from 2005 and 2006. Samples were collected on 10/20/04, 12/28/04, 10/18/05 and 2/27/06.
Data Reference: Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
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 Long Canyon Creek.
Lat/long: 33°30’38” N/117°09’40” W.
Temporal Representation: Samples were collected on 10/20/04, 12/28/04, 10/18/05 and 2/27/06.
Environmental Conditions: One sample represents the first storm event of each monitoring year that produces sufficient flow to collect a composite sample. In addition, another sample is collected during the monitoring year to represent a wet weather event.
QAPP Information: Quality assurance conducted according to the Riverside County's Consolidated Monitoring Plan.
QAPP Information Reference(s): Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
DECISION ID
16518
 
Pollutant: Iron
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: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Four of the 4 samples exceed the water quality objective.

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. Four of the 4 samples exceed the secondary drinking water MCL for iron 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 16518
 
LOE ID: 6264
 
Pollutant: Iron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
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 Riverside County Flood Control and Water Conservation District annual progress report from 2005 and 2006. Samples were collected on 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Data Reference: Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
Water Quality Objective/Criterion: From the Basin Plan, inland surface waters designated as domestic or municipal supply, shall not contain concentrations of iron in excess of the secondary maximum contaminant level 0.3 mg/L (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 Long Canyon Creek.
Lat/long: 33°30’38” N/117°09’40” W.
Temporal Representation: Samples were collected on the following dates: 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Environmental Conditions:
QAPP Information: Quality assurance conducted according to the Riverside County's Consolidated Monitoring Plan.
QAPP Information Reference(s): Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
DECISION ID
16519
 
Pollutant: Manganese
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: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Four of the 4 samples exceed the water quality objective.

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. Four of the 4 samples exceed the secondary drinking water MCL for Mn 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 16519
 
LOE ID: 6458
 
Pollutant: Manganese
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 4
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: All four samples collected exceed the water quality objective according to results in the Riverside County Flood Control and Water Conservation District annual progress report from 2005 and 2006. Samples were collected on 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Data Reference: Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.
 
Water Quality Objective/Criterion: From the Basin Plan, inland surface waters designated as domestic or municipal supply shall not contain concentrations of manganese in excess of the secondary maximum contaminant level 0.05 mg/L (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 station 780 on Long Canyon Creek. Lat/long: 33°30’38” N/117°09’40” W.
Temporal Representation: Samples were collected on the following dates: 10/20/04, 12/28/04, 10/18/05, and 2/27/06.
Environmental Conditions: One sample represents the first storm event of each monitoring year that produces sufficient flow to collect a composite sample. In addition, another sample is collected during the monitoring year to represent a wet weather event.
QAPP Information: Quality assurance conducted according to the Riverside County's Consolidated Monitoring Plan.
QAPP Information Reference(s): Watershed Annual Progress Report 2004 and 2005. Watershed Annual Progress Report 2005 and 2006.