Final California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name:	Santa Gertrudis Creek
Water Body ID:	CAR9024200020080825001546
Water Body Type:	River & Stream


DECISION ID	77857	Region 9
Santa Gertrudis Creek

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 4.3 of the Listing Policy. Under section 4.3 a single line of evidence is necessary to assess listing status. Five line of evidence is available in the administrative record to assess this pollutant. Seven of the Seven samples exceed the Basin Plan water quality objective for escherichia coli, Seven out of Seven samples exceeded the Water Quality Objective for Fecal Coliform, and Two of the Two samples exceeded the Evaluation Guideline for Total 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. Seven of the Seven samples exceed the Basin Plan water quality objective for escherichia coli, Seven out of Seven samples exceeded the Water Quality Objective for Fecal Coliform, and Two of the Two samples exceeded the Evaluation Guideline for Total Coliform and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 77857, Indicator Bacteria	Region 9
Santa Gertrudis Creek

LOE ID:

7402

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

All five 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 from October 2004 through February 2006.

Data Reference:

Watershed Annual Progress Report 2004 to 2005 and 2005 to 2006

SWAMP Data:

Non-SWAMP

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at Santa Gertrudis Creek near Temecula.
Lat/long: 33°31¿28¿ N/117°09¿50¿ W.

Temporal Representation:

Two to three samples were collected per monitoring year. Samples were collected from October 2004 through February 2006.

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. Two dry sampling events are also required each monitoring year; however, only one dry event was monitored in the 2004-2005 monitoring year and no dry events in the 2005-2006 monitoring year due to low flow.

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77857, Indicator Bacteria	Region 9
Santa Gertrudis Creek

LOE ID:

72779

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Two of the two samples exceeded the fecal coliform objective.

Data Reference:

Data for Various Pollutants in Riverside County, 2007-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Fecal Coliform concentration shall not exceed more than 400/100 ml. Water Quality Control Plan for the San Diego Basin.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at Santa Gertrudis Creek.

Temporal Representation:

Samples were collected between November 2008 and December 2008.

Environmental Conditions:

QAPP Information:

No QAPP was submitted. Sampling was done by municipalities in Riverside County pursuant to the Riverside County Municipal Stormwater Permit.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77857, Indicator Bacteria	Region 9
Santa Gertrudis Creek

LOE ID:

72781

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Two of the two samples exceeded the E. coli objective.

Data Reference:

Data for Various Pollutants in Riverside County, 2007-2009.

SWAMP Data:

Non-SWAMP

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at Santa Gertrudis Creek.

Temporal Representation:

Samples were collected between November 2008 and December 2008.

Environmental Conditions:

QAPP Information:

No QAPP was submitted. Sampling was done by municipalities in Riverside County pursuant to the Riverside County Municipal Stormwater Permit.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77857, Indicator Bacteria	Region 9
Santa Gertrudis Creek

LOE ID:

7151

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Data Reference:

San Diego, CA., Riverside, CA.

SWAMP Data:

Non-SWAMP

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at Santa Gertrudis Creek near Temecula.
Lat/long: 33°31¿28¿ N/117°09¿50¿ W.

Temporal Representation:

Two to three samples were collected per monitoring year. Samples were collected from October 2004 through February 2006.

Environmental Conditions:

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77857, Indicator Bacteria	Region 9
Santa Gertrudis Creek

LOE ID:

72780

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Two of the two samples exceeded the total coliform objective.

Data Reference:

Data for Various Pollutants in Riverside County, 2007-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Basin Plan for the San Diego Basin.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The Total Coliform concentration shall not exceed more than 10000/100 ml. Guidance for Fresh Water Beaches (CDPH).

Guideline Reference:

Draft Guidance for Fresh Water Beaches. Last Update: May 8, 2006. Initial Draft: November 1997. California Department of Public Health.

Spatial Representation:

The samples were collected at Santa Gertrudis Creek.

Temporal Representation:

Samples were collected between November 2008 and December 2008.

Environmental Conditions:

QAPP Information:

No QAPP was submitted. Sampling was done by municipalities in Riverside County pursuant to the Riverside County Municipal Stormwater Permit.

QAPP Information Reference(s):


DECISION ID	72416	Region 9
Santa Gertrudis Creek

Pollutant:	Chlorpyrifos
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The decision has not changed from the previous listing cycle. No new data were assessed for the current listing cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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. Seven of the nine samples exceed the Basin Plan water quality objective for chlorpyrifos. 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. Seven of the nine samples exceed the Basin Plan water quality objective for chlorpyrifos 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.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 72416, Chlorpyrifos	Region 9
Santa Gertrudis Creek

LOE ID:

7029

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Seven out of nine 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 from October 2004 through May 2006.

Data Reference:

Watershed Annual Progress Report 2004 to 2005 and 2005 to 2006

SWAMP Data:

Non-SWAMP

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

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

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

Samples were collected at Temecula Creek below Pala Road, lat/long: 33°28¿26.4¿ N/117°07¿46.1¿ W.

Temporal Representation:

Four to six samples are collected per monitoring year. Samples were collected from October 2004 through May 2006.

Environmental Conditions:

One sample represents the first storm event of each monitoring year that produces sufficient flow to collect a composite sample. In addition, three samples represent wet weather and two samples represent dry weather. However, one sampling event in the 2004-2005 monitoring year did not analyze for all constituents.

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):


DECISION ID	76151	Region 9
Santa Gertrudis Creek

Pollutant:	Copper
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The decision has not changed from the previous listing cycle. No new data were assessed for the current listing cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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. Two of the four samples exceed the Basin Plan water quality objective for copper. 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. Two of the four samples exceed the Basin Plan water quality objective for copper 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.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 76151, Copper	Region 9
Santa Gertrudis Creek

LOE ID:

7030

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Two out of four samples collected exceed the water quality objective for the 1-hour average concentration of copper. Two of four samples collected exceeds the water quality objective for the 4-day average concentration of copper according to results in the Riverside County Flood Control and Water Conservation District annual progress report from 2005 and 2006. Samples were collected from October 2004 through May 2006.

Data Reference:

Watershed Annual Progress Report 2004 to 2005 and 2005 to 2006

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

From the CTR, the dissolved copper chronic criterion is 3.1 ppb and the acute criterion is 4.8 ppb, but these criteria may vary depending upon hardness of the sample (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:

Spatial Representation:

Samples were collected at Santa Gertrudis Creek near Temecula.
Lat/long: 33°31¿28¿ N/117°09¿50¿ W.

Temporal Representation:

Two to three samples were collected per monitoring year. Samples were collected from October 2004 through February 2006.

Environmental Conditions:

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):


DECISION ID	76979	Region 9
Santa Gertrudis Creek

Pollutant:	Iron
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The decision has not changed from the previous listing cycle. No new data were assessed for the current listing cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Five of the five samples exceed the Basin Plan water quality objective for iron. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Five of the five samples exceed the Basin Plan water quality objective for iron 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.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 76979, Iron	Region 9
Santa Gertrudis Creek

LOE ID:

7031

Pollutant:

Iron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

All five of the samples exceeded the domestic or municipal supply water quality objective according to the results in Riverside County Flood Control and Water Conservation District annual monitoring program from 2005 and 2006. The five samples were collected between October 2004 and February 2006.

Data Reference:

Watershed Annual Progress Report 2004 to 2005 and 2005 to 2006

SWAMP Data:

Non-SWAMP

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at Santa Gertrudis Creek near Temecula.
Lat/long: 33°31¿28¿ N/117°09¿50¿ W.

Temporal Representation:

Two to three samples were collected per monitoring year. Samples were collected from October 2004 through February 2006.

Environmental Conditions:

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):


DECISION ID	77692	Region 9
Santa Gertrudis Creek

Pollutant:	Manganese
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The decision has not changed from the previous listing cycle. No new data were assessed for the current listing cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Regional Board Conclusion: 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 five samples exceed the Basin Plan water quality objective for Manganese. 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 five samples exceed the Basin Plan water quality objective for Manganese 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. State Board Review and Conclusion: The Regional Board staff mistakenly assessed manganese as a conventional pollutant and applied table 3.2 of the listing Policy. Manganese is a toxicant and should be assessed using Table 3.1 . State Water Board staff has corrected this error and revised the recommendation to List for manganese as follows: 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 five samples exceed the water quality objective for selenium. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for 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 five samples exceeded the water quality objective for selenium and this exceeds the allowable frequency under Section 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..

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 77692, Manganese	Region 9
Santa Gertrudis Creek

LOE ID:

7033

Pollutant:

Manganese

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Four of the five samples exceeded the water quality objective for Manganese in the Riverside County Flood Control and Water Conservation District annual monitoring reports from 2005 and 2006. The five samples were collected between October 2004 and February 2006.

Data Reference:

Watershed Annual Progress Report 2004 to 2005 and 2005 to 2006

SWAMP Data:

Non-SWAMP

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at Santa Gertrudis Creek near Temecula.
Lat/long: 33°31¿28¿ N/117°09¿50¿ W.

Temporal Representation:

Two to three samples were collected per monitoring year. Samples were collected from October 2004 through February 2006.

Environmental Conditions:

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):


DECISION ID	76007	Region 9
Santa Gertrudis Creek

Pollutant:	Nitrogen
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2023
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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 five samples exceed the 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 CWA section 303(d) List. 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 five samples exceed the objective and this exceeds the allowable frequency using table 3.1. 4. Pursuant to section of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 76007, Nitrogen	Region 9
Santa Gertrudis Creek

LOE ID:

7034

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Four of five samples exceeded the warm freshwater habitat water quality objective for Total Nitrogen in the Riverside County Flood Control and Water Conservation District annual monitoring report from 2005 and 2006. The five samples were collected between October 2004 and February 2006.

Data Reference:

Watershed Annual Progress Report 2004 to 2005 and 2005 to 2006

SWAMP Data:

Non-SWAMP

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).
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

Evaluation Guideline:

Guideline Reference:

Water Quality Control Plan for the San Diego Basin

Spatial Representation:

Samples were collected at Santa Gertrudis Creek near Temecula.
Lat/long: 33°31¿28¿ N/117°09¿50¿ W.

Temporal Representation:

Two to three samples were collected per monitoring year. Samples were collected from October 2004 through February 2006.

Environmental Conditions:

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):


DECISION ID	76980	Region 9
Santa Gertrudis Creek

Pollutant:	Phosphorus
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The decision has not changed from the previous listing cycle. No new data were assessed for the current listing cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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. Five of the five 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. Five of the five samples exceed the Basin Plan water quality objective for phosphorus 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.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 76980, Phosphorus	Region 9
Santa Gertrudis Creek

LOE ID:

7036

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

All five samples exceeded the warm freshwater habitat water quality objective for Phosphorus according to results in the Riverside County Flood Control and Water Conservation annual monitoring report from 2005 and 2006. The five samples were collected between October 2004 and February 2006.

Data Reference:

Watershed Annual Progress Report 2004 to 2005 and 2005 to 2006

SWAMP Data:

Non-SWAMP

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 Plan 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

Evaluation Guideline:

Guideline Reference:

Water Quality Control Plan for the San Diego Basin

Spatial Representation:

Samples were collected at Santa Gertrudis Creek near Temecula.
Lat/long: 33°31¿28¿ N/117°09¿50¿ W.

Temporal Representation:

Two to three samples were collected per monitoring year. Samples were collected from October 2004 through February 2006.

Environmental Conditions:

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):