Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name:	Elder Creek
Water Body ID:	CAR5191100019980817124745
Water Body Type:	River & Stream


DECISION ID	12991	Region 5
Elder Creek

Pollutant:	Pyrethroids
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Urban Runoff/Storm Sewers
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 3.1 of the Listing Policy. Two lines of evidence are available in the administrative record to assess this pollutant. Three of the 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 3 samples exceed the narrative toxicity objective and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. Sediment-bound pyrethroid pesticide concentrations were used to calculate toxic units (TUs) of multiple pyrethroid pesticides observed in sediments. Pyrethroid TU analyses correlated with distribution and magnitude of toxicity. 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:	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.

USEPA Action (if applicable):	USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.

Line of Evidence (LOE) for Decision ID 12991, Pyrethroids	Region 5
Elder Creek

LOE ID:

30938

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Three of three sediment toxicity testing samples violated the narrative toxicity objective. Toxicity observations were associated with pyrethroid pesticides. LC50s for sediment-bound pyrethroids were used in this study as toxicity threshold benchmarks in a Toxic Unit (TU) analysis normalized to organic carbon content. The TU analysis of Elder Creek sediment samples demonstrated that the three toxic samples had pyrethroid pesticide concentrations that would be expected to be acutely toxic. Sediment samples collected from Elder Creek had an average of 2.06 - 3.55 TUs of pyrethroid pesticides. Bifenthrin appears to play a dominant role in the toxicity observations, but was not the only pyrethroid found in toxic sediment samples. Other pyrethroids observed in the toxic samples from Elder Creek included cyfluthrin, cypermethrin, deltamethrin, esfenvalerate, lambda-cyhalothrin, and permethrin.

Data Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. (CVRWQCB, 2007)All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. (CVRWQCB, 2007)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control sediment using Dunnett's test in 10-day Hyalella azteca sediment toxicity tests. Arcsin squareroot transformation was used when necessary to meet the assumptions of normality and homogeneity of variance. Steel's test was used for comparison to control if these assumptions were not met after transformation.
LC50 values, based on 10-day exposure to Hyallela azteca of pyrethroids in sediment samples, were used to determine Toxic Unit (TUs) for pyrethroids in sediments. Urban creek sediment sample pyrethroid concentrations were compared the TUs to determine exceedances.

Guideline Reference:

Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Distribution and Toxicity of Sediment-Associated Pesticides in Agriculture-Dominated Water Bodies of Californias Central Valley

Spatial Representation:

Three samples were collected from Elder Creek at Gerber Road on different occasions (October 15, 2004; October 28, 2004; and March 10, 2005). Sediment toxicity was observed from all three of the samples. Sample location:Elder Creek at Gerber Road.

Temporal Representation:

Samples were collected August 2004 - August 2005.The Elder Creek sampling location reflects mixed commercial and residential land uses.

Environmental Conditions:

QAPP Information:

Data quality: Excellent.. Monitoring was conducted in accordance with the Quality Assurance Project Plan for Monitoring prepared for the Sacramento River Watershed Program (SRWP 1999a, 1999b, 2000b, 2001b, 2002b, 2003b, 2006).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 12991, Pyrethroids	Region 5
Elder Creek

LOE ID:

22096

Pollutant:

Sediment Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Three of three sediment toxicity testing samples violated the narrative toxicity objective. The three toxic (Mean mortality + standard deviation) sediment samples were collected from:Elder Creek at Gerber Road10/15/04: 35+40.310/28/04: 45+18.53/10/05: 30+10.7. Toxicity observations were associated with pyrethroid pesticides.

Data Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

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. (CVRWQCB, 2007)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Distribution and Toxicity of Sediment-Associated Pesticides in Agriculture-Dominated Water Bodies of Californias Central Valley

Spatial Representation:

Temporal Representation:

Samples were collected August 2004 - August 2005.The Elder Creek sampling location reflects mixed commercial and residential land uses.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	17933	Region 5
Elder Creek

Pollutant:	Sediment Toxicity
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Source Unknown
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	State Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Two lines of evidence are available in the administrative record to assess this pollutant. Three of the 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 3 samples exceed the narrative toxicity objective and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. Sediment-bound pyrethroid pesticide concentrations were used to calculate toxic units (TUs) of multiple pyrethroid pesticides observed in sediments. Pyrethroid TU analyses correlated with distribution and magnitude of toxicity. 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:	N/A

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	This listing recommendation was developed by State Board staff. It was not part of the Regional Board Record. After review of the available data and information, SWRCB 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.

USEPA Action (if applicable):	USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.

Line of Evidence (LOE) for Decision ID 17933, Sediment Toxicity	Region 5
Elder Creek

LOE ID:

22096

Pollutant:

Sediment Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

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. (CVRWQCB, 2007)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Distribution and Toxicity of Sediment-Associated Pesticides in Agriculture-Dominated Water Bodies of Californias Central Valley

Spatial Representation:

Temporal Representation:

Samples were collected August 2004 - August 2005.The Elder Creek sampling location reflects mixed commercial and residential land uses.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	4935	Region 5
Elder Creek

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2006)
Revision Status	Original
Sources:	Storm sewers
TMDL Name:	Sacramento Area Urban Creeks TMDLs
TMDL Project Code:	194
Date TMDL Approved by USEPA:	11/30/2004
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under sections 2.2 and 4.1 of the Listing Policy. Under section 4.1 a single line of evidence is necessary to assess delisting status. One line of evidence is available in the administrative record to assess this pollutant. A large number of samples exceed the water quality objective. The Sacramento Area Urban Creeks TMDL was approved by the RWQCB in 2004 and subsequently approved by USEPA in 2004. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list and placing it in the Water Quality Limited Segments Being Addressed 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 40 samples exceeded the CDFG criteria; all five samples taken in 2001 were non-detects; in 2003, 70 percent of the detections were above the CDFG criterion (14 ng/L) and this exceeds the allowable frequency listed in Table 4.1 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 met.

Regional Board Decision Recommendation:	This is a decision made by the State Water Resources Control Board and approved by the USEPA in 2006 . No new data were assessed by the Regional Board for 2008. 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.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 4935, Chlorpyrifos	Region 5
Elder Creek

LOE ID:

31394

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Twenty-five water samples were collected from Elder Creek from February 2001 to April 2003, representing twenty-one calculated 4-day average chlorpyrifos concentrations and twenty-five 1-hour average chlorpyrifos concentrations. Ten of the twenty-one available calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Eight of the twenty-five available 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion of 0.025 ug/L.

Data Reference:

Concentrations of pesticides in Sacramento metropolitan area rainwater and creeks during the 2001, 2002, 2003 orchard dormant spray season. Rancho Cordova, CA: Central Valley RWQCB

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion 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

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

California Department of Fish and Game Hazard Assessment Chlorpyrifos Criteria: 0.015 ug/L as a4-day average chlorpyrifos concentration, and 0.025 ug/L as a 1-hour average chlorpyrifos concentration, not to be exceeded more than once every three years.

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 from Elder Creek at five sites: Excelsior Road, Bradshaw Road, Elder Creek Road, Elk Grove-Florin Road, and Franklin Blvd.

Temporal Representation:

Samples were collected from February 2001 to April 2003 at variable intervals (e.g. every three to five days) during storms.

Environmental Conditions:

QAPP Information:

Spector et al., 2004. Concentrations of Pesticides
in Sacramento Metropolitan Area Rainwater and Creeks during the 2001, 2002 and 2003 Orchard Dormant Spray Seasons.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 4935, Chlorpyrifos	Region 5
Elder Creek

LOE ID:

31395

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Thirteen water samples were collected from Elder Creek in February 2004 to April 2007, representing eight calculated 4-day average chlorpyrifos concentrations and eight 1-hour average chlorpyrifos concentrations. Zero of the eight available calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Zero of the eight available 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion of 0.025 ug/L. Five samples had a detection limit of 0.05 ug/L, which is higher than both the water quality criteria guideline values of 0.015 and 0.025 ug/L. Therefore, in accordance with Section 6.1.5.5 of the Listing Policy, these five samples were not used in this analysis.

Data Reference:

Sacramento River watershed program (SRWP) water quality database 1991-2003. Davis, CA

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

California Department of Fish and Game Hazard Assessment Chlorpyrifos Criteria: 0.015 ug/L as a 4-day average chlorpyrifos concentration, and 0.025 ug/L as a 1-hour average chlorpyrifos concentration, not to be exceeded more than once every three years.

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 from Elder Creek at Morrison Creek.

Temporal Representation:

Samples were collected at variable intervals (e.g., every two weeks or every twenty days) from February 2004 to April 2007.

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2002-0206) requirements (CVRWQCB, 2002)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 4935, Chlorpyrifos	Region 5
Elder Creek

LOE ID:

2637

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

In 2001 and 2003, Regional Board staff monitored the segment of Elder Creek that runs adjacent to a 250-acre commercial nursery to better characterize nursery contributions of pesticides to Elder Creek, a tributary of Morrison Creek. Five samples were taken in 2001; all were non-detects. In 2003, chlorpyrifos concentrations at the Elder Creek downstream monitoring site (downstream of a 250-acre commercial nursery) were the highest overall, with 70 percent of the chlorpyrifos detections above the CDFG aquatic life water quality criterion for chlorpyrifos (0.020 ug/L). From mid-March to mid-April 2003, chlorpyrifos concentrations in samples collected from the downstream Elder Creek monitoring site were consistently high (ranging from 0.035 ug/L to 0.320 ug/L) while samples collected from the upstream Elder Creek monitoring site had non-detectable chlorpyrifos concentrations 80 percent of the time. Twenty samples were taken at two locations; 5 samples at the Bradshaw Road site exceeded the CDFG criteria (Spector et al., 2004).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The narrative pesticide objectives state, in part:
- No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses,
- Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses,
- Pesticide concentrations shall not exceed those allowable by applicable antidegradation policies, and
- Pesticide concentrations shall not exceed the lowest levels technically and economically achievable.

The Basin Plan's narrative water quality objective for toxicity states that 'all waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.'

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

CDFG Hazard Assessment Criteria - 14 ng/L 4-day average.

Guideline Reference:

Placeholder reference 2006 303(d)

Spatial Representation:

Samples were collected beneath the water surface as near as possible to the center of the stream when water levels were low or when access was only possible from the bank. Otherwise, three to four grab samples were collected as one integrated grab sample. Elder Creek was monitored by Regional Board staff at two locations in 2003 - upstream and downstream of Village Nursery at Excelsior Road and Bradshaw Road. In 2001, Regional Board staff monitored Elder Creek at three sites, Elder Creek Road, Elk Grove-Florin Road, and Franklin Boulevard.

Temporal Representation:

Storm events were sampled during the orchard dormant spray season months of January and February 2001 and 2002, and January through April 2003, to determine pesticide concentrations in rain and creeks during and after the orchard dormant spray season.

Environmental Conditions:

QAPP Information:

During each monitoring season, additional samples were collected for quality assurance/quality control (QA/QC) purposes. Four types of quality assurance samples were collected to confirm the integrity of analytical results reported in this three-year monitoring study. The QA/QC samples included sample duplicates, equipment blanks, matrix spikes, and matrix spike duplicates. The procedures used for collecting the QA/QC samples are based on the San Joaquin River TMDL Quality Assurance Project Plan. During this 2001-2003 study, approximately 15-25 percent of the samples collected were either equipment blanks, sample duplicates, or matrix spikes and matrix spike duplicates.

QAPP Information Reference(s):


DECISION ID	5211	Region 5
Elder Creek

Pollutant:	Diazinon
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2006)
Revision Status	Original
Sources:	Agriculture \| Urban Runoff/Storm Sewers
TMDL Name:	Sacramento Area Urban Creeks TMDLs
TMDL Project Code:	194
Date TMDL Approved by USEPA:	11/30/2004
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under sections 2.2 and 4.1 of the Listing Policy. Under section 4.1 a single line of evidence is necessary to assess delisting status. One line of evidence is available in the administrative record to assess this pollutant. The Sacramento Area Urban Creeks TMDL was approved by the RWQCB in 2004 and subsequently approved by USEPA in 2004. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list and placing it in the Water Quality Limited Segments Being Addressed category because a TMDL and implementation plan has been approved and are expected to result in attainment of the standard. 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. One of 25 samples exceeded the CDFG criteria but the number of samples is insufficient to determine with the confidence and power required by the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	This is a decision made by the State Water Resources Control Board and approved by the USEPA in 2006 . No new data were assessed by the Regional Board for 2008. 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.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 5211, Diazinon	Region 5
Elder Creek

LOE ID:

31396

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Twelve water samples were collected from Elder Creek from February 2002 through February 2007, representing twelve calculated 4-day average diazinon concentrations and twelve 1-hour average diazinon concentrations. Four of the twelve available calculated 4-day average diazinon concentrations exceeded the 4-day average diazinon criterion of 0.100 ug/L. Three of the twelve available 1-hour average diazinon concentrations exceeded the 1-hour average diazinon criterion of 0.160 ug/L.

Data Reference:

Sacramento River watershed program (SRWP) water quality database 1991-2003. Davis, CA

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

California Department of Fish and Game Hazard Assessment Diazinon Criteria: 0.160 ug/L as a 1-hour average concentration, and 0.100 ug/L as a 4-day average concentration, not to be exceeded more than once every three years.

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 from Elder Creek at Morrison Creek.

Temporal Representation:

Samples were collected on 02/02/2004, 02/18/2004, 04/13/2004, 10/06/2004, 01/28/2005, 02/15/2005, 04/12/2005, 02/07/2006, 02/27/2006, 03/06/2006, 12/08/2006, and 02/09/2007.

Environmental Conditions:

Elder Creek is located in the Sacramento urban area.

QAPP Information:

Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2002-0206) requirements (CVRWQCB, 2002)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 5211, Diazinon	Region 5
Elder Creek

LOE ID:

2639

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

In 2001 and 2003, Regional Board staff monitored the segment of Elder Creek that runs adjacent to a 250-acre commercial nursery to better characterize nursery contributions of pesticides to Elder Creek, a tributary of Morrison Creek. Diazinon concentrations were low to non-detectable at the upstream and downstream Elder Creek monitoring sites. Five samples were taken in 2001 at three locations; one of the samples taken at Franklin Blvd. exceeded the CDFG criteria. In 2003, 20 samples were taken at two locations; none of the samples exceeded the CDFG criteria (Spector et al., 2004).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The narrative pesticide objectives state, in part:
- No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses,
- Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses,
- Pesticide concentrations shall not exceed those allowable by applicable antidegradation policies, and
- Pesticide concentrations shall not exceed the lowest levels technically and economically achievable.

The Basin Plan's narrative water quality objective for toxicity states that "all waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life."

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

CDFG Hazard Assessment Criteria 0.16 ug/L 1-hour average (Siepman & Finlayson, 2000; Finlayson, 2004).

Guideline Reference:

Placeholder reference 2006 303(d)

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):