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

# Supporting Information

## Regional Board 5 - Central Valley Region

Water Body Name: | Elk Grove Creek
Water Body ID: | CAR5191100019980817130203
Water Body Type: | River & Stream

DECISION ID | 5216
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 | Revised
Sources: | Source Unknown
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
Weight of Evidence: | This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess pollutant. None of 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 removing this water segment-pollutant combination from the 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. None of 7 available 4-day average concentrations exceeded the 4-day average maximum concentration criterion and a minimum sample size of 28 is needed to delist according to 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.
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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 5216

LOE ID: | 2641
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 18
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | 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. In 2001, 6 samples were taken at 3 sampling sites; all samples were non-detects (Spector et al., 2004).
Data Reference: | Placeholder reference 2006 303(d)
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 Plans 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 and 25 ng/L 1-hour average.
Guideline Reference: | Placeholder reference 2006 303(d)
Spatial Representation: | In 2001, Elk Grove Creek was monitored by the Regional Board at two sites - at Waterman Road and at Emerald Vista Drive.
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 | 5179
Pollutant: | Diazinon
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 | Revised
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
Weight of Evidence: | This pollutant is being considered for removal on the section 303(d) list under sections 2.2 and 4.2 of the Listing Policy. Under 4.2 of the Policy, a minimum of one line of evidence is needed to assess listing status. One 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 removing this water segment-pollutant combination from the section 303(d) list. There is sufficient justification to place it in the Being Addressed portion of the 303(d) list because a TMDL has been completed and approved by RWQCB and USEPA, and is 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 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1 of the Policy. 3. Five of 11 available 4-day average concentrations exceeded the 4-day average maximum concentration criterion and these exceed the allowable frequency listed in Table 4.1 of the Listing Policy. In addition, 4 of 11 available 1-hour average concentrations exceeded the 4-day average concentration criterion and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. The Sacramento County Urban Creeks TMDL has been approved by the Central Valley Water Board in 2004 and approved by USEPA on 11/30/2004. 5. 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 5179

LOE ID: | 2643
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 6
Number of Exceedances: | 4
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | 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. In 2001, 6 samples were taken at 3 sampling sites; 2 samples at Waterman Road were non-detects; the 2 samples taken at Emerald Vista Drive and Florin Creek at Franklin Blvd. exceeded the CDFG criteria (Spector et al., 2004).
Data Reference: | Placeholder reference 2006 303(d)
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 Plans 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: | In 2001, Elk Grove Creek was monitored by the Regional Board at two sites - at Waterman Road and at Emerald Vista Drive.
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: | San Joaquin River TMDL Quality Assurance Project Plan.
QAPP Information Reference(s):
LOE ID: | 22082
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 11
Number of Exceedances: | 5
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | Eleven water samples were collected from Elk Grove Creek from February 2002 through February 2007, representing 11 4-day average concentrations and 11 1-hour average concentrations.5 of 11 four-day average concentrations exceeded the four day maximum concentration guideline of 0.100 µg/L.4 of 11 one-hour average concentrations exceeded the maximum 1-hour concentration of 0.160 µg/L.
Data Reference: | Sacramento stormwater urban tributary NPDES permit monitoring data, 2003 to 2007
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 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
| Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | California Fish and Game Hazard Assessment Criteria - 0.160 µg/L 1-hour average and 0.100 µg/L 4-day average concentration (Siepmann and Finlayson, 2000 and 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 collected from Elk Grove Creek at Laguna.
Temporal Representation: | Samples were collected on 02/02/2004, 02/18/2004, 04/13/2004, 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.Stream located in an urban area.
Environmental Conditions: |
QAPP Information: | Monitoring was conducted in accordance with Municipal Storm Water Permitting Program. Data was collected by the Sacramento Stormwater Quality Partnership for their municipal separate storm sewer systems permit.
QAPP Information Reference(s):