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

# Supporting Information

## Regional Board 5 - Central Valley Region

Water Body Name: | Sacramento River ( Red Bluff to Knights Landing)
Water Body ID: | CAR5201000019990126140752
Water Body Type: | River & Stream

DECISION ID | 7157
Pollutant: | Unknown Toxicity
Final Listing Decision: | Do Not 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
Sources: | Source Unknown
Expected TMDL Completion Date: | 2019
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. Six lines of evidence are available in the administrative record to assess 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. 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. Twenty-four of 108 samples tested with Ceriodaphnia (survival or reproductive toxicity) exceeded the narrative toxicity objective and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Thirteen of 54 samples tested with Pimephales (survival or reproductive toxicity) exceeded the narrative toxicity objective and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 5. In addition, 2 of 44 samples tested with Selenastrum exceeded the water quality objective and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. 6. 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 7157

LOE ID: | 22633
Pollutant: | Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 44
Number of Exceedances: | 2
Data and Information Type: | TOXICITY TESTING
Data Used to Asses Water Quality: | Four-day growth tests were conducted with Selenastrum capricornutum in association with Sacramento River Watershed Program annual monitoring activities. Two of the 44 samples exhibited a significant decrease in growth as compared to the laboratory control and violated the narrative toxicity objective. The following is a summary of monitoring results by site and year. 2003 - 2004: Sacramento River near Hamilton City - None of the 4 samples exhibited a significant decrease in growth (cell numbers) as compared to the laboratory control. Sacramento River at Colusa - None of the 4 samples exhibited a significant decrease in growth (cell numbers) as compared to the laboratory control. 2006 - 2007: Sacramento River near Hamilton City - None of the 18 samples exhibited a significant decrease in growth as compared to the laboratory control. The results reported for the sample collected on 6 July 2006 were those of a re-test (SRWP 2008). Sacramento River at Colusa - Two of the 18 samples exhibited a significant decrease in growth as compared to the laboratory control. The toxic samples (growth response reported as a percentage of control response is provided in parentheses) were collected on 25 July 2006 (57) and 14 March 2007 (44). Phase I Toxicity Identification Evaluations (TIEs) were performed on the sample collected from the Sacramento River at Colusa on 14 March 2007. The sample was not toxic during the TIE testing, indicating that the toxicity was not persistent, the magnitude of the toxicity had decreased, and the contaminant that caused the toxicity was susceptible to rapid degradation. Metals and herbicides are two classes of contaminants that are of concern when algal toxicity is observed. As metals are typically conserved (i.e., toxicity from metals should not be expected to degrade over time), it is unlikely that metals could have caused the toxicity. There were no pesticides detected in the SRCOL [Sacramento River at Colusa] sample, which was extracted for analyses by the analytical lab 1.6 days after sample collection (SRWP 2008).
Data Reference: | Sacramento River watershed program (SRWP) water quality database. Davis, CA
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. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances (CVRWQCB, 2007).
Objective/Criterion Reference: | 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: | Statistically significant difference from control with a short-term chronic (4-day) growth test.
Guideline Reference: | Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-013
Spatial Representation: | Samples were collected from the Sacramento River near Hamilton City and at Colusa.
Temporal Representation: | 2003 - 2004: Sampling was scheduled to correspond to the following events/dates: mid-wet season (20 January 2004); post-organophosphate pesticide dormant spray application (3 February 2004); rice field discharge season, dry weather event (9 June 2004); and dry season, low flows (27 July 2004). 2006 - 2007: Sampling was generally conducted on a monthly basis from April 2006 through August 2007.
Environmental Conditions: |
QAPP Information: | Data quality: Good. 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):
LOE ID: | 4515
Pollutant: | Unknown Toxicity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):
LOE ID: | 26226
Pollutant: | Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 54
Number of Exceedances: | 9
Data and Information Type: | TOXICITY TESTING
Data Used to Asses Water Quality: | Seven-day growth toxicity tests were conducted with Pimephales promelas. Nine of 54 samples exhibited significant reduction in growth compared to the laboratory control and violated the narrative toxicity objective. Growth endpoints for P. promelas were not statistically compared to control results if survival endpoints were significantly less than the controls. The following is a summary of the test results by year. Growth Endpoint 1999-2000 Sacramento River near Hamilton City This location was not included in the 1998-1999 monitoring effort. Sacramento River at Colusa Three of the 12 samples exhibited significant reduction in growth compared to the laboratory control. The toxic samples were collected on the following dates (percent of control in parentheses): 19 August 1998 (81), 15 December 1998 (87), and 17 March 1999 (72). 2003-2004 Sacramento River near Hamilton City None of the 4 samples were reported to have exhibited significant reduction in growth compared to the laboratory control. However, growth endpoints for P. promelas were not statistically compared to control results if survival endpoints were significantly less than the controls, as was the case with samples collected on 9 June 2004 and 27 July 2004. The results reported for the 20 January 2004 and 3 February 2004 are those from tests modified to control pathogen-related mortality. Sacramento River at Colusa Two of the 4 samples exhibited significant reduction in growth compared to the laboratory control. The toxic samples were collected during the following dates: 9 June 2004 and 27 July 2004. The data summary does not provide the corresponding data for the control associated with each test, but rather provides the range of data for separate controls associated multiple tests. Therefore, percent of control was included in this assessment. The results reported for the 20 January 2004 and 3 February 2004 are those from tests modified to control pathogen-related mortality. 2006-2007 Sacramento River near Hamilton City None of the 17 samples exhibited significant reduction in growth compared to the laboratory control. The test organisms in the site water collected on 25 April 2007 exhibited pathogen-related mortalities and were excluded from evaluation of ambient toxicity (SRWP 2008). The 25 April 2007 sampling event was not included in this assessment. Sacramento River at Colusa Four of the 17 samples exhibited significant reduction in growth compared to the laboratory control. Toxic samples were collected on the following dates (percent of control in parentheses): 30 May 2006 (87), 6 July 2006 (81), 12 December 2006 (79), and 27 June 2007 (86). The test organisms in the site water collected on 25 April 2007 exhibited pathogen-related mortalities and were excluded from evaluation of ambient toxicity (SRWP 2008). The 25 April 2007 sampling event was not included in this assessment.
Data Reference: | Sacramento River watershed program (SRWP) water quality database. Davis, CA
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. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances (CVRWQCB, 2007).
Objective/Criterion Reference: | 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: | Statistically significant difference from control with 7-day growth toxicity tests. Significant toxicity is defined as a statistically significant (p<0.5) reduction in growth compared to the laboratory control.
Guideline Reference: | Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-013
Spatial Representation: | Samples were collected from the Sacramento River near Hamilton City and at Colusa.
Temporal Representation: | 1998 -1999: Samples were collected monthly from June 1998 through May 1999. 2003 - 2004: Sampling was scheduled to correspond to the following events/dates: mid-wet season (20 January 2004); post-organophosphate pesticide dormant spray application (3 February 2004); rice field discharge season, dry weather event (9 June 2004); and dry season, low flows (27 July 2004). 2006-2007: Sampling was generally conducted on a monthly basis from April 2006 through August 2007.
Environmental Conditions: |
QAPP Information: | Data quality: Good. Monitoring was conducted in accordance with the Quality Assurance Project Plan for Monitoring prepared for the Sacramento River Watershed Program (SRWP 1999a, 1999b, 2003, 2006). The test results reported for 20 September 2006 were those of a re-test (SRWP 2008). The test organisms in the site water collected on 25 April 2007 exhibited pathogen-related mortalities and were excluded from evaluation of ambient toxicity (SRWP 2008). The 25 April 2007 sampling event was not included in this assessment.
QAPP Information Reference(s):
LOE ID: | 26227
Pollutant: | Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 54
Number of Exceedances: | 4
Data and Information Type: | TOXICITY TESTING
Data Used to Asses Water Quality: | Seven-day survival toxicity tests were conducted with Pimephales promelas. Four of the 54 samples exhibited a significant increase in mortality compared to the laboratory control and violated the narrative toxicity objective. The following is a summary of the test results by year. Survival Endpoint 1998-1999 Sacramento River near Hamilton City This location was not included in the 1998-1999 monitoring effort. Sacramento River at Colusa One of the 12 samples exhibited a significant increase in mortality compared to the laboratory control. The toxic sample was collected on 3 February 2004 (60% survival), 62% of control. 2003-2004 Sacramento River near Hamilton City Two of the 4 samples exhibited a significant increase in mortality compared to the laboratory control. The toxic samples were collected on the following dates: 9 June 2004 (15% survival) and 27 July 2004 (5% survival). Sacramento River at Colusa None of the 4 samples exhibited a significant increase in mortality compared to the laboratory control. 2006-2007 Sacramento River near Hamilton City One of the 17 samples exhibited a significant increase in mortality compared to the laboratory control. The toxic sample (survival reported as a percentage of control response is provided in the parentheses) was collected on 12 December 2006 (45). The test organisms in the site water collected on 25 April 2007 exhibited pathogen-related mortalities and were excluded from evaluation of ambient toxicity (SRWP 2008). The 25 April 2007 sampling event was not included in this assessment. Phase I Toxicity Identification Evaluations (TIEs) were conducted using the 12 December 2006 sample. The toxicity was persistent during the TIEs. The magnitude of the toxicity was not decreased and onset of the toxicity was not delayed. None of the TIE treatments removed the toxicity (SRWP 2008). No analyte list pesticides were detected in the sample (SRWP 2008). The sample was extracted for organic analyses ~2.5 days after sample collection (SRWP 2008). Sacramento River at Colusa None of the 17 samples exhibited a significant increase in mortality compared to the laboratory control. The test organisms in the site water collected on 25 April 2007 exhibited pathogen-related mortalities and were excluded from evaluation of ambient toxicity (SRWP 2008). The 25 April 2007 sampling event was not included in this assessment.
Data Reference: | Sacramento River watershed program (SRWP) water quality database. Davis, CA
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. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances (CVRWQCB, 2007).
Objective/Criterion Reference: | 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: | Statistically significant difference from control with 7-day survival toxicity tests. Significant toxicity is defined as a statistically significant (p<0.5) increase in mortality (≥20%) compared to the laboratory control.
Guideline Reference: | Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-013
Spatial Representation: | All samples were collected from the Sacramento River above Bend Bridge.
Temporal Representation: | 1998 -1999: Samples were collected monthly from June 1998 through May 1999. 2003 - 2004: Sampling was scheduled to correspond to the following events/dates: mid-wet season (20 January 2004); post-organophosphate pesticide dormant spray application (3 February 2004); rice field discharge season, dry weather event (9 June 2004); and dry season, low flows (27 July 2004). 2006-2007: Sampling was generally conducted on a monthly basis from April 2006 through August 2007.
Environmental Conditions: |
QAPP Information: | Data quality: Good. Monitoring was conducted in accordance with the Quality Assurance Project Plan for Monitoring prepared for the Sacramento River Watershed Program (SRWP 1999a, 1999b, 2003, 2006). The test results reported for 20 September 2006 were those of a re-test (SRWP 2008). The test organisms in the site water collected on 25 April 2007 exhibited pathogen-related mortalities and were excluded from evaluation of ambient toxicity (SRWP 2008). The 25 April 2007 sampling event was not included in this assessment.
QAPP Information Reference(s):
LOE ID: | 22870
Pollutant: | Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 108
Number of Exceedances: | 19
Data and Information Type: | TOXICITY TESTING
Data Used to Asses Water Quality: | Seven-day reproduction toxicity tests were conducted with Ceriodaphnia dubia in association with Sacramento River Watershed Program annual monitoring activities at two locations (near Hamilton City and at Colusa). Nineteen (19) of the 108 samples exhibited significant reduction in reproduction compared to the laboratory control and violated the narrative toxicity objective. The following is a summary of toxicity test results by site and year.Reproduction Endpoint1999-2000Sacramento River near Hamilton CityThis location was not included in the 1998-1999 monitoring effort.Sacramento River at ColusaNone of the 12 samples exhibited significant reduction in reproduction compared to the laboratory control.1999-2000Sacramento River near Hamilton CityOne of the 11 samples exhibited significant reduction in reproduction compared to the laboratory control. The toxic sample was collected 15 February 2000 (80% of control). Sacramento River at ColusaNone of the 12 samples exhibited significant reduction in reproduction compared to the laboratory control. 2000-2001Sacramento River near Hamilton CityThis site was not included in the 2000-2001 monitoring activities.Sacramento River at ColusaFour of the 9 samples exhibited significant reduction in reproduction compared to the laboratory control. Toxic samples were collected on the following dates: 20 September 2000, 30 October 2000, 26 January 2001, and 21 June 2001 (66% of control). The data summary does not provide the corresponding data for the control associated with each test (with the exception of 21 June 2001), but rather provides the range of data for separate controls associated multiple tests. Therefore, percent of control was not calculated.2001-2002Sacramento River near Hamilton CityOne of the 4 samples exhibited significant reduction in reproduction compared to the laboratory control. The toxic sample was collected on 14 May 2002. Percent of control not included for same reason as 2000-2001 monitoring summary. Sacramento River at ColusaTwo of the 4 samples exhibited significant reduction in reproduction compared to the laboratory control. The toxic samples were collected on 21 February 2002 and 15 May 2002. Percent of control not included for same reason as 2000-2001 monitoring summary. 2002-2003Sacramento River near Hamilton CityNone of the 6 samples exhibited significant reduction in reproduction compared to the laboratory control. Sacramento River at ColusaNone of the 6 samples exhibited significant reduction in reproduction compared to the laboratory control. 2003-2004Sacramento River near Hamilton CityThree of the 4 samples exhibited significant reduction in reproduction compared to the laboratory control. The toxic samples were collected during the following dates: 20 January 2004, 9 June 2004, and 27 July 2004. Percent of control not included for same reason as 2000-2001 monitoring summary.Sacramento River at ColusaTwo of the 4 samples exhibited significant reduction in reproduction compared to the laboratory control. The toxic samples were collected during the following dates: 9 June 2004 and 27 July 2004. Percent of control not included for same reason as 2000-2001 monitoring summary.2006-2007Sacramento River near Hamilton CityTwo of the 18 samples exhibited significant reduction in reproduction compared to the laboratory control. The toxic samples were collected on the following dates (percentage of control response provided in parentheses): 25 October 2006 (82) and 25 April 2007 (74).Sacramento River at ColusaFour of the 18 samples exhibited significant reduction in reproduction compared to the laboratory control. The toxic samples were collected on the following dates (percentage of control response provided in parentheses): 20 April 2006 (83), 25 July 2006 (75), 25 April 2007 (82), and 6 June 2007 (83).
Data Reference: | Sacramento River watershed program (SRWP) water quality database. Davis, CA
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. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CVRWQCB, 2007).
Objective/Criterion Reference: | 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: | Statistically significant difference from control with 7-day reproduction toxicity tests. Significant toxicity is defined as decreased reproduction that is statistically different from controls at the 95% confidence level.
Guideline Reference: | Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-013
Spatial Representation: | Samples were collected from the Sacramento River near Hamilton City and at Colusa.
Temporal Representation: | 1998-1999: Samples werecollected monthly from June 1998 through May 1999. 1999 - 2000: Samples were collected from the Sacramento River at Colusa on a monthly basis from June 1999 through May 2000 (12 sampling events) and from the Sacramento River near Hamilton City on a monthly basis from July 1999 through May 2000 (11 sampling events). 2000 - 2001: Samples were collected on 20 July 2000, 20 September 2000, 18 October 2000, 30 October 2000, 26 January 2001, 7 February 2001, 8 April 2001, 29 May 2001, and 21 June 2001. 2001 - 2002: Sampling was scheduled to correspond to the following events/dates: late dry season, low flows (25 September 2001); seasonal first-flush storm (2-3 November 2001); significant rainfall of >0.5 inches, organophosphate pesticide application period (20-21 February 2002); and rice field discharge period, late wet season (14-15 May 2002). 2002 - 2003: Sampling was scheduled to correspond to the following events/dates: late dry season, low flows (2 October 2002); first significant storm event of season (9-10 November 2002); rain event, organophosphate pesticide dormant spray application (23-24 January 2003); late wet season, rain events (15-16 March 2003 and 5 & 13 April 2003); and rice field discharge season, dry weather event (9 June 2003). 2003 - 2004: Sampling was scheduled to correspond to the following events/dates: mid-wet season (20 January 2004); post-organophosphate pesticide dormant spray application (3 February 2004); rice field discharge season, dry weather event (9 June 2004); and dry season, low flows (27 July 2004). 2006 - 2007: Sampling was generally conducted on a monthly basis from April 2006 through August 2007.
Environmental Conditions: |
QAPP Information: | Data quality: Good. 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):
LOE ID: | 22857
Pollutant: | Toxicity
LOE Subgroup: | Toxicity
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 108
Number of Exceedances: | 5
Data and Information Type: | TOXICITY TESTING
Data Used to Asses Water Quality: | Seven-day survival toxicity tests were conducted with Ceriodaphnia dubia in association with Sacramento River Watershed Program annual monitoring activities at two locations (near Hamilton City and at Colusa). Five of the 108 samples exhibited a significant increase in mortality compared to the laboratory control and violated the narrative toxicity objective. The following is a summary of toxicity test results by site and year.Survival Endpoint1998-1999Sacramento River near Hamilton CityThis location was not included in the 1998-1999 monitoring effort. Sacramento River at ColusaNone of the 12 samples exhibited a significant increase in mortality compared to the laboratory control. 1999-2000Sacramento River near Hamilton CityNone of the 11 samples exhibited a significant increase in mortality compared to the laboratory control.Sacramento River at ColusaNone of the 12 samples exhibited a significant increase in mortality compared to the laboratory control. 2000-2001Sacramento River near Hamilton CityThis site was not included in the 2000-2001 monitoring activities.Sacramento River at ColusaNone of the 9 samples exhibited a significant increase in mortality compared to the laboratory control.2001-2002Sacramento River near Hamilton CityOne of the 4 samples exhibited a significant increase in mortality compared to the laboratory control. The toxic sample was collected on 25 September 2001 (100% mortality).Sacramento River at ColusaOne of the 4 samples exhibited a significant increase in mortality compared to the laboratory control. The toxic sample was collected on 25 September 2001 (100% mortality).2002-2003Sacramento River near Hamilton CityOne of the 6 samples exhibited a significant increase in mortality compared to the laboratory control. The toxic sample was collected on 15 March 2003 (100% mortality). Sacramento River at ColusaNone of the 6 samples exhibited a significant increase in mortality compared to the laboratory control.2003-2004Sacramento River near Hamilton CityNone of the 4 samples exhibited a significant increase in mortality compared to the laboratory control.Sacramento River at ColusaNone of the 4 samples exhibited a significant increase in mortality compared to the laboratory control.2006-2007Sacramento River near Hamilton CityOne of the 18 samples exhibited a significant increase in mortality compared to the laboratory control. The toxic sample was collected on 12 December 2006 (initial test: 0% of control response, immediate re-test: 40% of control response). It should be noted that of the 12 water samples collected from across the watershed during this sampling event (December 2006), 11 caused complete mortality of the test organisms in the initial test.Phase I Toxicity Identification Evaluations (TIEs) were conducted using the 12 December 2006 sample. Although persistent during the TIEs, the toxicity was delayed and its magnitude was decreased. Toxicity was removed by the following TIE treatments: C-8 Solid Phase Extraction and piperonyl butoxide (PBO). This suggests that dissolved non-polar organic contaminants and metabolically-activated substances, or a substance with both properties, caused the toxicity (SRWP 2008). Sacramento River at ColusaOne of the 18 samples exhibited a significant increase in mortality compared to the laboratory control. The toxic sample was collected on 12 December 2006 (initial test: 0% of control response, immediate re-test: 40% of control response). It should be noted that of the 12 water samples collected from across the watershed during this sampling event (December 2006), 11 caused complete mortality of the test organisms in the initial test.Phase I Toxicity Identification Evaluations (TIEs) were conducted using the 12 December 2006 sample.
Data Reference: | Sacramento River watershed program (SRWP) water quality database. Davis, CA
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. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CVRWQCB, 2007).
Objective/Criterion Reference: | 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: | Statistically significant difference from control with 7-day survival toxicity tests. Significant toxicity is defined as mortality (>20%) that is statistically different from controls at the 95% confidence level.
Guideline Reference: | Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-013
Spatial Representation: | Samples were collected from the Sacramento River near Hamilton City and at Colusa.
Temporal Representation: | 1998 - 1999: Samples were collected monthly from June 1998 through May 1999. 1999 - 2000: Samples were collected from the Sacramento River at Colusa on a monthly basis from June 1999 through May 2000 (12 sampling events) and from the Sacramento River near Hamilton City on a monthly basis from July 1999 through May 2000 (11 sampling events). 2000 - 2001: Samples were collected on 20 July 2000, 20 September 2000, 18 October 2000, 30 October 2000, 26 January 2001, 7 February 2001, 8 April 2001, 29 May 2001, and 21 June 2001. 2001 - 2002: Sampling was scheduled to correspond to the following events/dates: late dry season, low flows (25 September 2001); seasonal first-flush storm (2-3 November 2001); significant rainfall of >0.5 inches, organophosphate pesticide application period (20-21 February 2002); and rice field discharge period, late wet season (14-15 May 2002). 2002 - 2003: Sampling was scheduled to correspond to the following events/dates: late dry season, low flows (2 October 2002); first significant storm event of season (9-10 November 2002); rain event, organophosphate pesticide dormant spray application (23-24 January 2003); late wet season, rain events (15-16 March 2003 and 5 & 13 April 2003); and rice field discharge season, dry weather event (9 June 2003). 2003 - 2004: Sampling was scheduled to correspond to the following events/dates: mid-wet season (20 January 2004); post-organophosphate pesticide dormant spray application (3 February 2004); rice field discharge season, dry weather event (9 June 2004); and dry season, low flows (27 July 2004). 2006 - 2007: Sampling was generally conducted on a monthly basis from April 2006 through August 2007.
Environmental Conditions: |
QAPP Information: | Data quality: Good. 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):

DECISION ID | 14066
Pollutant: | Fecal Coliform
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 lines of evidence are available in the administrative record to assess this pollutant. None 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 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. None of 23 calculated geometric means exceeded the fecal coliform 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 applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 14066

LOE ID: | 22853
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 23
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Asses Water Quality: | The Department of Water Resources collected 25 samples from March 2002 to April 2004. The geometric mean per month per site was calculated from the samples and 0 out of the 23 calculated geometric means exceeded the evaluation objective.
Data Reference: | Project effects on water quality designated beneficial uses for surface waters, and results for bacterial monitoring of swimming areas in 2003. FERC Project No. 2100. Sacramento, CA: State of CA Department of Water Resources
Water Quality Objective/Criterion: | In waters designated for contact recreation (REC-1), the fecal coliform concentration based on a minimum of not less than five samples for any 30-day period shall not exceed a geometric mean of 200/100 ml, nor shall more than ten percent of the total number of samples taken during any 30-day period exceed 400/100 ml.
Objective/Criterion Reference: | 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: |
Guideline Reference:
Spatial Representation: | Samples were collected from the Sacramento River upstream of Feather River.
Temporal Representation: | Sampling occurred from March 2002 to April 2004.
Environmental Conditions: |
QAPP Information: | Data quality: Good. Quality Control for all of the elements described in section 6.1.4 of the Policy was conducted in accordance with the Laboratory QAPP developed by the State of California Resources Agency Department of Water Resources (DWR, 2005). Quality Assurance Project Plan for Oroville Facilities Relicensing FERC Project No. 2100 SP-W1. Department of Water Resources (DWR). Oroville Facilities Relicensing FERC Project No. 2100. January 2005.
QAPP Information Reference(s):

DECISION ID | 14492
Pollutant: | DDT
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Agriculture
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Two 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. Two of 6 composite fish samples exceeded the Evaluation Guideline (OEHHA FCG for DDT of 21 ug/kg) and, therefore, exceed the narrative toxicity objective, 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 14492

LOE ID: | 26123
Pollutant: | DDT
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Fish whole body
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 6
Number of Exceedances: | 2
Data and Information Type: | Fish tissue analysis
Data Used to Asses Water Quality: | Fish were collected for composite fish tissue total DDT analysis from the Sacramento River at the following locations and dates: - Colusa on 16 August 2005 (Channel Catfish) and on 11 October 2005 (Sacramento Sucker). - Grimes on 12 October 2005 (Channel Catfish) - Hamilton City on 31 October 2005 (Sacramento Sucker) - Ord Bend on 15 August 2005 (Sacramento Sucker) - Woodson Bridge on 15 August 2005 (Sacramento Sucker) The forms of DDT analyzed included: DDT (o,p), DDT (p,p), DDD (o,p), DDD (p,p), DDE (o,p), DDE (p,p), DDMU (p,p). Two composite samples that exceeded the Total DDT OEHHA screening value of 21 µg/kg. These were: - One composite sample of Channel Catfish from Colusa had 87.49 µg/kg of total DDT. - One composite sample of Channel Catfish from Grimes had 43.97 µg/kg of total DDT. Sacramento Sucker, Carp and White Catfish were captured from the Sacramento River at Veterans Bridge on 28 September 2005 and composite fish tissue samples for eac species were analyzed for different forms of DDT, including: DDT (o,p), DDT (p,p), DDD (o,p), DDD (p,p), DDE (o,p), DDE (p,p), DDMU (p,p). Two of the 3 composite fish tissue samples (for Carp and Channel Catfish) exceeded the OEHHA value of 21 µg/kg. The composite fish tissue sample for Carp had a total DDT concentration of 59.08 µg/kg. The composite fish tissue sample for Channel catfish had total DDT concentration of 109.09 µg/kg.
Data Reference: | Sacramento River Watershed Program Annual Reports for 1999-2000, 2000-2001, 2001-2002, 2002-2003, and 2003-2004; and BDAT data 1998-2003
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.
Objective/Criterion Reference: | 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: | OEHHA 2008 Fish Contaminant Goals (FCG) are based on cancer risk assessments using an 8-Ounce/Week (prior to cooking) consumption rate of 32 g/day. The FCG used as a screening value for total DDT (with a cancer slope factor of 0.34 mg/kg/day) should be less than 21 µg/kg.
Guideline Reference: | Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation: | Samples were collected from various locations: Channel Catfish and Sacramento Sucker at Colusa; Sacramento Sucker, Channel Catfish at Grimes; Sacramento Sucker at Hamilton City; Sacramento Sucker at Ord Bend; and Sacramento Sucker from Woodson Bridge.
Temporal Representation: | - On 16 August 2005 at Colusa (Channel Catfish and Sacramento Sucker). - On 12 October 2005 at Grimes (Channel Catfish). - On 31 October 2005 at Hamilton City (Sacramento Sucker). - On 15 August 2005 at Ord Bend (Sacramento Sucker). - On 15 August 2005 at Woodson Bridge (Sacramento Sucker).
Environmental Conditions: |
QAPP Information: | Data Quality: Good. Monitoring was conducted in accordance with Sacramento River Watershed Program QAPP requirements.
QAPP Information Reference(s): | Quality Assurance Project Plans prepared for Sacramento River Watershed Program

DECISION ID | 14496
Pollutant: | Dieldrin
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Agriculture
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Two 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. Two of 2 composite fish tissue samples exceed the Evaluation Guideline for Dieldrin (OEHHA Fish Contaminant Goal of 0.46 ug/kg), which exceeds the narrative toxicity objective and, therefore, 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 14496

LOE ID: | 26124
Pollutant: | Dieldrin
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Fish whole body
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 6
Number of Exceedances: | 2
Data and Information Type: | Fish tissue analysis
Data Used to Asses Water Quality: | Two of the 6 composite fish tissue samples exceeded the Dieldrin Evaluation Guigeline for Dieldrin (OEHHA FCG of 0.46 µg/kg, and this exceeds narrative toxicity objective and the allowable frequency listed in Table 3.1 of the Listing Policy. The exceedances were: i) One composite sample of Channel Catfish from Colusa had 2.03 µg/kg of Dieldrin. ii) One composite of Channel Catfish from Grimes had 3.74 µg/kg of Dieldrin.
Data Reference: | Sacramento River Watershed Program Annual Reports for 1999-2000, 2000-2001, 2001-2002, 2002-2003, and 2003-2004; and BDAT data 1998-2003
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.
Objective/Criterion Reference: | 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: | OEHHA 2008 Fish Contaminant Goals (FCG) are based on cancer risk assessments using an 8-Ounce/Week (prior to cooking) consumption rate of 32 g/day. The FCG used as a screening value for Dieldrin (with a cancer slope factor of 16 mg/kg/day) should be less than 0.46 µg/kg.
Guideline Reference: | Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation: | Samples were collected from various locations: Channel Catfish and Sacramento Sucker at Colusa; Channel Catfish at Grimes; Sacramento Sucker at Hamilton City; Sacramento Sucker at Ord Bend; and Sacramento Sucker from Woodson Bridge.
Temporal Representation: | Fish were collected on the following dates: Colusa on 16 August 2005 (Channel catfish) and on 11 October 2005 (Sacramento Sucker); Grimes on 12 October 2005 (Channel Catfish); Hamilton City on 31 October 2005 (Sacramento Sucker); Ord Bend on 15 August 2005 (Sacramento Sucker); and Woodson Bridge on 15 August 2005 (Sacramento Sucker).
Environmental Conditions: |
QAPP Information: | Data Quality: Good. Monitoring was conducted in accordance with Sacramento River Watershed Program QAPP requirements.
QAPP Information Reference(s): | Quality Assurance Project Plans prepared for Sacramento River Watershed Program

DECISION ID | 6856
Pollutant: | Mercury
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)(2006)
Revision Status | Revised
Sources: | Resource Extraction
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. One-hundred-and-ten 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. One-hundred-and-ten of 362 samples exceed the USEPA fish tissue criterion for human health 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 6856

LOE ID: | 26352
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Total
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 5
Number of Exceedances: | 3
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | Fish were sampled for tissue analysis at two locations from this reach, at Colusa and Knights Landing. A total of 3 out of 5 samples exceeded the USEPA fish tissue criterion for human health. 1) Sacramento River at Colusa: The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Sacramento Pikeminnow- one 5-fish composite sample, 0.51 ppm, 1 exceedence; Sacramento Sucker- one 6-fish composite sample, 0.08 ppm, no exceedences. 2) Sacramento River at Knights Landing: The average wet weight mercury concentration in fish tissue was 0.52 ppm for the 3 samples collected at this location. The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Largemouth Bass- 2 composite samples, 0.60 and 0.76 ppm, 2 exceedences; Sacramento Sucker- one 5-fish composite sample, 0.19 ppm, no exceedences. All 3 composite samples were collected from fish with average total lengths greater than 150 mm, which represent fish most commonly caught and consumed by sport fishers and their families.
Data Reference: | SWRCB. 2003. Toxic Substances Monitoring Program: Freshwater Bioaccumulation Monitoring Program 2001-2003. State Water Resources Control Board, Division of Water Quality. Unpublished Data.
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. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: | 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: | The USEPA Fish Tissue Residue Criterion for methylmercury in fish is 0.3 mg/kg (0.3 ppm) for the protection of human health. This is the concentration in fish tissue that should not be exceeded based on a total fish and shellfish consumption-weighted rate of 0.0175 kg fish/day. (USEPA, 2001)
Guideline Reference: | Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
Spatial Representation: | Samples were collected at two locations from this reach of the Sacramento River at Colusa and Knights Landing.
Temporal Representation: | Fish samples were collected during two sampling events on 9/13/2002 and from 10/29/2002 to10/30/2002.
Environmental Conditions: | Significant gold mining activity occurred during the Gold Rush era within the Sacramento River watershed (USGS, 2005).
QAPP Information: | Data quality: Excellent.. Quality Control for the fish sampling, tissue preparation, mercury analysis, and QA sample analysis portions of this study was conducted as described in the Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 2001-2002 (CDFG, 2003).
QAPP Information Reference(s):
LOE ID: | 26292
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Total
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 88
Number of Exceedances: | 23
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | Fish were sampled for tissue analysis at four locations from this reach. A total of 23 out of 88 samples exceeded the USEPA fish tissue criterion for human health. 1) Sacramento River at Colusa: 17 samples, 5 exceedences, range 0.04-1.34 ppm, 0.33 ppm average wet weight concentration; 2) Sacramento River near Grimes: 34 samples, 6 exceedences, range 0.01-1.68 ppm, 0.23 ppm average wet weight concentration; 3) Sacramento River at Hamiliton City: 18 samples, 6 exceedences, range 0.01-1.76 ppm, 0.32 ppm average wet weight concentration; 4) Sacramento River at Ord Bend: 19 samples, 6 exceedences, range 0.01-1.50 ppm, 0.37 ppm average wet weight concentration. Fish tissue was analyzed from Carp, Largemouth Bass, Rainbow Trout, Redear Sunfish, Sacramento Pikeminnow, Sacramento Sucker and Smallmouth Bass. All 88 samples were collected from fish with total lengths greater than 150 mm, which represent fish most commonly caught and consumed by sport fishers and their families.
Data Reference: | CVRWQCB. 2004. TMDL Fish Tissue Sampling- Cache Creek and Sacramento River Watersheds. Central Valley Regional Water Quality Control Board; and California Department of Fish and Game. Unpublished Data. August 2004.
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. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: | 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: | The USEPA Fish Tissue Residue Criterion for methylmercury in fish is 0.3 mg/kg (0.3 ppm) for the protection of human health. This is the concentration in fish tissue that should not be exceeded based on a total fish and shellfish consumption-weighted rate of 0.0175 kg fish/day. (USEPA, 2001)
Guideline Reference: | Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
Spatial Representation: | Samples were collected at four locations from this reach of the Sacramento River: near Colusa at the Bridge Street bridge; near Grimes and RM 125; near Hamilton City at the Hwy 32 bridge; and near Ord Bend at the Ord Ferry Road bridge.
Temporal Representation: | Fish samples were collected during one sampling event from 10/14/2003 to 10/16/2003.
Environmental Conditions: | Significant gold mining activity occurred during the Gold Rush era within the Sacramento River watershed (USGS, 2005).
QAPP Information: | Data Quality: Excellent.. Quality Control for all of the elements described in section 6.1.4 of the Policy was conducted in accordance with the Laboratory QAPP developed by Moss Landing Marine Laboratories (MLML, 2005). This data was also collected and analyzed in accordance with the CALFED Mercury Project QAPP (Puckett and van Buuren, 2000).
QAPP Information Reference(s):
LOE ID: | 26350
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Total
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | One 5 fish composite sample of Hardhead was collected from this reach of the Sacramento River. The wet weight mercury concentration of this fish tissue sample was 0.13 ppm, which does not exceed the USEPA criterion. The composite sample was collected from fish with an average total length greater than 150 mm, which represents fish most commonly caught and consumed by sport fishers and their families.
Data Reference: | SWRCB-DWQ. 2002. Toxic Substances Monitoring Program: Freshwater Bioaccumulation Monitoring: TSM Program Data 1978-2000. State Water Resources Control Board, Division of Water Quality
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. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: | 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: | The USEPA Fish Tissue Residue Criterion for methylmercury in fish is 0.3 mg/kg (0.3 ppm) for the protection of human health. This is the concentration in fish tissue that should not be exceeded based on a total fish and shellfish consumption-weighted rate of 0.0175 kg fish/day. (USEPA, 2001)
Guideline Reference: | Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
Spatial Representation: | Samples were collected at one location from this reach of the Sacramento River downstream from Hamilton City near the confluence with Pine Creek.
Temporal Representation: | The fish sample was collected on 7/30/1981.
Environmental Conditions: | Significant gold mining activity occurred during the Gold Rush era within the Sacramento River watershed (USGS, 2005).
QAPP Information: | Data quality: Excellent.. Quality Control for the fish sampling, tissue preparation, mercury analysis, and QA sample analysis portions of this study was conducted as described in the Toxic Substance Monitoring Report for 1981 (La Karo et al., 1982).
QAPP Information Reference(s):
LOE ID: | 22595
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Total
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 166
Number of Exceedances: | 53
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | Fish were sampled for tissue analysis at six locations from this reach. A total of 53 out of 166 samples exceeded the USEPA fish tissue criterion for human health. 1) Sacramento River near Butte City: 20 samples, 10 exceedences, range 0.04-0.75 ppm, 0.33 ppm average wet weight concentration; 2) Sacramento River downstream from Colusa: 46 samples, 19 exceedences, range 0.04-0.90 ppm, 0.33 ppm average wet weight concentration; 3) Sacramento River downstream from Grimes: 33 samples, 8 exceedences, range 0.03-0.96 ppm, 0.26 ppm average wet weight concentration; 4) Sacramento River at Hamiliton City: 27 samples, 4 exceedences, range 0.01-1.15 ppm, 0.21 ppm average wet weight concentration; 5) Sacramento River at Ord Bend: 20 samples, 5 exceedences, range 0.02-1.14 ppm, 0.23 ppm average wet weight concentration; 6) Sacramento River at Woodson Bridge: 20 samples, 7 exceedences, range 0.02-1.26 ppm, 0.35 ppm average wet weight concentration. Fish tissue was analyzed from Channel Catfish, Hardhead, Largemouth Bass, Rainbow Trout, Redear Sunfish, Sacramento Pikeminnow, Sacramento Sucker and Steelhead Trout. All 166 samples were collected from fish with total lengths greater than 150 mm, which represent fish most commonly caught and consumed by sport fishers and their families.
Data Reference: | Fish Mercury Project, Year 1 Annual Report, Sport Fish Sampling and Analysis. Collaborating parties: San Francisco Estuary Institute, California Department of Fish and Game, Moss Landing Marine Laboratories, California Office of Environmental Health Hazard Assessment. Final Technical Report. CBDA Project # ERP 02D-P6729. May 2007
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. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: | 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: | The USEPA Fish Tissue Residue Criterion for methylmercury in fish is 0.3 mg/kg (0.3 ppm) for the protection of human health. This is the concentration in fish tissue that should not be exceeded based on a total fish and shellfish consumption-weighted rate of 0.0175 kg fish/day. (USEPA, 2001)
Guideline Reference: | Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
Spatial Representation: | Samples were collected at six locations from this reach of the Sacramento River: near Butte City at the Hwy 162 bridge; 5 miles downstream from Colusa near Moons Bend; 1.5 miles downstream from Grimes near Eddys Ferry; near Hamilton City at the Hwy 32 bridge; near Ord Bend appoximately 0.2 miles downstream of the Ord Ferry Road bridge; and directly downstream from the Woodson Bridge crossing.
Temporal Representation: | Fish samples were collected during three sampling events: from 8/15/2005 to 8/17/2005; from 10/11/2005 to 10/12/2005; and on 10/31/2005.
Environmental Conditions: | Significant gold mining activity occurred during the Gold Rush era within the Sacramento River watershed (USGS, 2005).
QAPP Information: | Data quality: Excellent.. Quality Control for all of the elements described in section 6.1.4 of the Policy was conducted in accordance with the Laboratory QAPP developed by Moss Landing Marine Laboratories (MLML, 2005). This data was also collected and analyzed in accordance with the CALFED Mercury Project QAPP (Puckett and van Buuren, 2000).
QAPP Information Reference(s):
LOE ID: | 26346
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Total
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 93
Number of Exceedances: | 29
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | Fish were sampled for tissue analysis at four locations from this reach. A total of 29 out of 93 samples exceeded the USEPA fish tissue criterion for human health. 1) Sacramento River downstream from Colusa: 22 samples, 9 exceedences, range 0.03-1.04 ppm, 0.32 ppm average wet weight concentration; 2) Sacramento River at Knights Landing: 41 samples, 13 exceedences, range 0.04-1.00 ppm, 0.29 ppm average wet weight concentration; 3) Sacramento River near Hamiliton City: 15 samples, 6 exceedences, range 0.05-0.55 ppm, 0.24 ppm average wet weight concentration; 4) Sacramento River at Tisdale Boat Ramp: 15 samples, 1 exceedence, range 0.08-0.32 ppm, 0.17 ppm average wet weight concentration. Fish tissue was analyzed from American Shad, Carp, Channel Catfish, Chinook Salmon, Hardhead, Largemouth Bass, Redear Sunfish, Sacramento Pikeminnow and Sacramento Sucker. All 93 samples were collected from fish with total lengths greater than 150 mm, which represent fish most commonly caught and consumed by sport fishers and their families.
Data Reference: | Fish Mercury Project, Year 2 Annual Report, Sport Fish Sampling and Analysis. Final Report. October 2007
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. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: | 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: | The USEPA Fish Tissue Residue Criterion for methylmercury in fish is 0.3 mg/kg (0.3 ppm) for the protection of human health. This is the concentration in fish tissue that should not be exceeded based on a total fish and shellfish consumption-weighted rate of 0.0175 kg fish/day. (USEPA, 2001)
Guideline Reference: | Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
Spatial Representation: | Samples were collected at four locations from this reach of the Sacramento River: 5.6 miles downstream from Colusa near Moons Bend; 0.5 miles upstream of the Colusa Basin Drainage Canal input near Knights Landing; near Hamilton City and Jenny Lind Bend; and near the Tisdale Weir boat ramp.
Temporal Representation: | Fish samples were collected during three sampling events on 5/9/2006, 7/25/2006 and from 8/2/2006 to 8/2/2006.
Environmental Conditions: | Significant gold mining activity occurred during the Gold Rush era within the Sacramento River watershed (USGS, 2005).
QAPP Information: | Data quality: Excellent.. Quality Control for all of the elements described in section 6.1.4 of the Policy was conducted in accordance with the Laboratory QAPP developed by Moss Landing Marine Laboratories (MLML, 2005). This data was also collected and analyzed in accordance with the CALFED Mercury Project QAPP (Puckett and van Buuren, 2000).
QAPP Information Reference(s):
LOE ID: | 26348
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Total
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 9
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | Fish were sampled by SRWP for tissue analysis at two locations from this reach, at Colusa and downstream from Hamilton City. A total of 2 out of 9 samples exceeded the USEPA fish tissue criterion for human health. 1) Sacramento River at Colusa: The average wet weight mercury concentration in fish tissue was 0.20 ppm for the 5 samples collected at this location. The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Carp- one 5-fish composite sample, 0.19 ppm, no exceedences; Sacramento Pikeminnow- 2 composite samples, 0.15 and 0.30 ppm, 1 exceedence; Sacramento Sucker- one 5-fish composite sample, 0.06 ppm, no exceedences; and Striped Bass- 1 sample, 0.30 ppm, 1 exceedence. 2) Sacramento River downstream from Hamilton City: The average wet weight mercury concentration in fish tissue was 0.14 ppm for the 4 samples collected at this location. The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Sacramento Pikeminnow- 2 composite samples, 0.22 and 0.29 ppm, no exceedences; and Sacramento Sucker- 2 composite samples, both 0.03 ppm , no exceedences. All 9 samples were collected from fish with total lengths greater than 150 mm, which represent fish most commonly caught and consumed by sport fishers and their families.
Data Reference: | Sacramento River Watershed Program Annual Reports for 1999-2000, 2000-2001, 2001-2002, 2002-2003, and 2003-2004; and BDAT data 1998-2003
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. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: | 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: | The USEPA Fish Tissue Residue Criterion for methylmercury in fish is 0.3 mg/kg (0.3 ppm) for the protection of human health. This is the concentration in fish tissue that should not be exceeded based on a total fish and shellfish consumption-weighted rate of 0.0175 kg fish/day. (USEPA, 2001)
Guideline Reference: | Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
Spatial Representation: | Samples were collected at two locations from this reach of the Sacramento River: near Colusa at the Bridge Street bridge; and downstream from Hamilton City near the confluence with Pine Creek.
Temporal Representation: | Fish samples were collected during two sampling events conducted during 1998 and 2000.
Environmental Conditions: | Significant gold mining activity occurred during the Gold Rush era within the Sacramento River watershed (USGS, 2005).
QAPP Information: | Data quality: Excellent.. Quality Control for all of the elements described in section 6.1.4 of the Policy was conducted in accordance with the Sacramento River Watershed Program QAPPs prepared by Larry Walker Associates (LWA, 1998; LWA, 2000).
QAPP Information Reference(s): | Quality Assurance Project Plans prepared for Sacramento River Watershed Program

DECISION ID | 13025
Pollutant: | PCBs (Polychlorinated biphenyls)
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
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.5 (Bioaccumulation of Pollutants in Aquatic Fish Tissue) of the Listing Policy. Under section 3.5 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 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 six samples exceed the OEHHA fish contaminant goal for human health (3.6 ng/g) 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 13025

LOE ID: | 25694
Pollutant: | PCBs (Polychlorinated biphenyls)
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Fish fillet
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 6
Number of Exceedances: | 4
Data and Information Type: | Fish tissue analysis
Data Used to Asses Water Quality: | Samples were analyzed for the presence of 48 individual PCB congeners and Aroclors 1248, 1254 and 1260. For the purpose of this assessment, data considered were the sum of PCB congeners (total PCBs), reported as ng/g, wet weight. The OEHHA and SWAMP recommend use of total PCBs for evaluating contamination. The values for each of the PCB congeners were surrogate corrected. For the purpose of determining the sum of PCB congeners, results for individual congeners that were below the reporting limit (0.199 ng/g) were treated as non-detects. Total PCBs in four of the six composite samples collected from the Sacramento River between Red Bluff and Knights Landing exceeded 3.6 ng/g. Total PCBs by species (composite sample) were as follows: 102.499 ng/g in channel catfish collected at Colusa, 9.151 ng/g in channel catfish collected at Grimes, 6.504 in Sacramento sucker collected at Colusa, 5.767 in Sacramento sucker collected at Woodson Bridge, and 3.431 in Sacramento sucker collected at Ord Bend. For the Sacramento sucker composite sample collected at Hamilton City, none of the PCB congeners that were analyzed were recorded at values above the reporting limit (0.199 ng/g). Composite samples consisted of equal-weight tissue samples from up to five fish of similar size and combined into a single 200 g composite sample (SRWP 2006).
Data Reference: | Sacramento River watershed program (SRWP) water quality database. Davis, CA
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. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: | 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: | The California Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal for total PCBs in fish is 3.6 ng/g (3.6 ppb), wet weight, to protect human health. This concentration in fish tissue should not be exceeded, based on a total fish and shellfish consumption rate of 8 ounces per week (prior to cooking) (32 g/day) (OEHHA 2008). This goal incorporates a maximum cancer risk level of one in a million (no more than one additional cancer in a population of one million people consuming these fish).
Guideline Reference: | Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Spatial Representation: | Samples were collected from the Sacramento River at Colusa, Grimes, Hamilton City, Ord Bend, and Woodson Bridge.
Temporal Representation: | Fish samples were collected at Colusa on 16 August 2005 and 11 October 2005; Grimes on 12 October 2005; Hamilton City on 31 October 2005; Ord Bend on 15 August 2005; and Woodson Bridge on 15 August 2005.
Environmental Conditions: |
QAPP Information: | Sampling and analyses were conducted in accordance with the Quality Assurance Project Plan, Sacramento River Watershed Program, Monitoring 2005-2007 (SRWP 2006). Fish tissue samples were collected by the California Department of Fish and Game Moss Landing Marine Lab, using protocols detailed in Sampling and Processing Trace Metal and Synthetic Organic Samples of Marine Mussels, Freshwater Clams, Marine Crabs, Marine and Freshwater Fish and Sediments: DFG Method 102 (CDFG 2001). A holding time violation was noted in the dataset for all samples included in this line of evidence. The amount of time by which the holding time was exceeded was not provided.
QAPP Information Reference(s):

DECISION ID | 4613
Pollutant: | Chlorpyrifos
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2006)
Revision Status | Original
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. None of the measurements exceed the water quality guideline. Based on the readily available data and information, the weight of evidence indicates that there is insufficient 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 CDFG criteria used complies with the requirements of section 6.1.3 of the Policy. 2. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 3. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 4. None of the 36 samples obtained from 1998, 1999 and 2000 from this site exceeded the CDFG criteria. 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: | 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.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 4613

LOE ID: | 2663
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 36
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | Data was obtained from the USGS NWISweb data, a 1998, 1999 and 2000 California Department of Pesticide Regulation SWDB study, SRWP 1998-2000 database. None of 36 samples exceeded the CDFG criteria. Some of the concentrations were cited as less than values and as such could not be used in this assessment. (USGS, 2005), (LWA, 2002b).
Data Reference: | Placeholder reference 2006 303(d)
Water Quality Objective/Criterion: | 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. Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the executive Officer. Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of pesticides in excess of the Maximum Contaminant Levels set forth in California Code of Regulations, Title 22, Division 4, Chapter 15.
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: | Samples were taken from the following locations on the Sacramento River: Colusa, Hamilton, the Colusa Drain and Bryte.
Temporal Representation: | Samples were taken from 1996 - 2001.
Environmental Conditions: |
QAPP Information: | Data from USGS reports are considered of adequate quality per section 6.1.4 of the Policy. Data from the Sacramento River Watershed Program (SRWP) Waters Quality Database (Larry Walker Associates, April 2002) are considered adequate.
QAPP Information Reference(s):

DECISION ID | 4668
Pollutant: | Diazinon
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2006)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | Two 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 insufficient 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 CDFG criteria used complies with the requirements of section 6.1.3 of the Policy. 2. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 3. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 4. Six of 179 samples exceeded the CDFG criteria and these do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. Additionally, when the chronic criteria could be applied, 2 out of 20 data set averages (4-day) exceeded the chronic criteria. 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: | 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.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 4668

LOE ID: | 2664
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 166
Number of Exceedances: | 6
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | There were 181 samples total but 15 were considered to be of "questionable" quality and therefore were not used for this assessment. Of the remaining 166 samples, 6 exceeded the acute criteria. When the chronic criteria could be applied, 2 out of 20 data set averages (4-day) exceeded the chronic criteria. (Dileanis et al., 2002), (Dileanis, 2003a), (Dileanis, 2003b), (Holmes et al., 2000), (LWA, 2002b).
Data Reference: | Placeholder reference 2006 303(d)
Water Quality Objective/Criterion: | 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. Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the executive Officer. Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of pesticides in excess of the Maximum Contaminant Levels set forth in California Code of Regulations, Title 22, Division 4, Chapter 15.
Objective/Criterion Reference: | Placeholder reference 2006 303(d)
Evaluation Guideline: | CDFG Hazard Assessment Criteria - 0.16 ug/L 1-hour average (acute), 0.10 ug/L 4-day average (chronic). (Siepman & Finlayson, 2000; Finlayson, 2004).
Guideline Reference: | Placeholder reference 2006 303(d)
Spatial Representation: | Samples were taken from the following locations on the Sacramento River: at Bend Ferry Rd Bridge, Butte City, Colusa, Hamilton City, Vina and the Colusa Drain.
Temporal Representation: | Samples were taken from 1994 - 2001.
Environmental Conditions: |
QAPP Information: | Data from USGS reports are considered of adequate quality per section 6.1.4 of the Policy. Data from the Sacramento River Watershed Program (SRWP) Waters Quality Database (Larry Walker Associates, April 2002) are considered adequate.
QAPP Information Reference(s):
LOE ID: | 2665
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 13
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | None of the 13 samples exceeded the CDFG criteria. (Spector et al., 2004).
Data Reference: | Placeholder reference 2006 303(d)
Water Quality Objective/Criterion: | 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. Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the executive Officer. Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of pesticides in excess of the Maximum Contaminant Levels set forth in California Code of Regulations, Title 22, Division 4, Chapter 15. Pesticide concentrations shall not exceed those allowable by applicable antidegradation policies (see State Water Resources Control Board Resolution No. 68-16 and 40 C.F.R. Section 131.12). Pesticide concentrations shall not exceed the lowest levels technically and economically achievable. A trend in declining water quality has not been established per the Policy in section 3.1.10.
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: | All samples were taken at the Sacramento River at Colusa
Temporal Representation: | Two storm events were sampled for the 2004 TMDL project in the Sacramento River Basin. For storm 1 sampling was conducted from 28 January to 3 February. For storm 2 the sampling period began on 16 February and extended until 21 February.
Environmental Conditions: |
QAPP Information: | Data from CDFA are considered of adequate quality.
QAPP Information Reference(s):