| Water Body Name: | Agatha Canal (Merced County) |
| Water Body ID: | CAR5412000020090110150509 |
| Water Body Type: | River & Stream |
DECISION ID |
15933 |
Region 5 |
Agatha Canal (Merced County) |
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| Pollutant: | pH |
| Final Listing Decision: | List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Sources: | Source Unknown |
| Expected TMDL Completion Date: | 2021 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.
One line of evidence are available in the administrative record to assess this pollutant. Seven 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. Seven of 28 samples exceed the pH objective found in the Basin Plan and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
| USEPA Action (if applicable): | USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant. |
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| LOE ID: | 20963 | ||||
| Pollutant: | pH | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Warm Freshwater Habitat | ||||
| Aquatic Life Use: | Warm Freshwater Habitat | ||||
| Number of Samples: | 28 | ||||
| Number of Exceedances: | 7 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | 7 of the 28 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for pH. | ||||
| Data Reference: | San Joaquin River SWAMP Monitoring Data - Grassland Bypass | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | pH levels should not be lower than 6.5 or higher than 8.5 (Basin Plan Objective) | ||||
| Objective/Criterion Reference: | Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Samples were collected at Agatha Canal @ Mallard Road. | ||||
| Temporal Representation: | The samples were collected from Oct 27 1995 to Feb 18 1997 | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program. | ||||
| QAPP Information Reference(s): | |||||
DECISION ID |
9499 |
Region 5 |
Agatha Canal (Merced County) |
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| Pollutant: | Selenium |
| Final Listing Decision: | List on 303(d) list (being addressed by USEPA approved TMDL) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Sources: | Source Unknown |
| TMDL Name: | Grasslands Marshes Selenium TMDL |
| TMDL Project Code: | 1209 |
| Date TMDL Approved by USEPA: | 05/26/2000 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | Regional Board Conclusion:
This pollutant is being considered for listing under sections 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Data is available from 1 line of evidence for this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification for placing this water segment-pollution combination on the section 303(d) list. The recommendation is based on staff findings that 18 of 334 available concentrations exceeded the water quality objective and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. According to BinomBal listing is recommended if a sample size of 334 has 29 or more samples that exceed the evaluation criteria. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. State Board Review and Conclusion: The April 19, 2010 State Water Board staff report for the 2010 Integrated Report found that an incorrect water quality objective was mistakenly used to evaluate the water quality data for selenium and make a Do Not List decision. State Water Board staff re-evaluated the available data and the line of evidence and recommendation has been revised. Based on the result of data re-evaluation, State Water Board staff recommend to List Agatha Canal for selenium. Based on comments received on the April 19, 2010 State Water Board staff report for the 2010 Integrated Report, State Water Board staff recommended to move this this water body from the 303(d) list Category 5 to the "Being Addressed Category" for selenium because this listing is covered under the Selenium TMDL for Grasslands Marshes. On August 4, 2010 the State Water Board approved the staff listing recommendation to place this water body on the 303(d) list (being addressed by a USEPA approved TMDL) for selenium. The final language for the recommendation is: This pollutant is being considered for listing under sections 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Data is available from 1 line of evidence for this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water body-pollutant combination on the section 303(d) list. The recommendation is based on staff findings that 19 of 131 monthly means exceeded the water quality objective and this exceeds the allowable frequency using Table 3.1 of the Listing Policy. According to the binomial equation, listing is recommended if a sample size of 131 has 12 or more samples that exceed the evaluation criteria. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the following changes to the decision: An incorrect water quality objective was used to evaluate the water quality data for selenium and make a Do Not List decision. State Water Board staff re-evaluated the data and the line of evidence and recommendation has been revised. Based on the result of data re-evaluation, State Water Board staff recommend to List Agatha Canal for selenium. After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list in the "Being Addressed Category" because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem but there is an approved TMDL in place to address the problem. |
| USEPA Action (if applicable): | |
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| LOE ID: | 20954 | ||||
| Pollutant: | Selenium | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Total | ||||
| Beneficial Use: | Warm Freshwater Habitat | ||||
| Aquatic Life Use: | Warm Freshwater Habitat | ||||
| Number of Samples: | 131 | ||||
| Number of Exceedances: | 19 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Nineteen of the 131 monthly means exceeded the evaluation objective for Selenium. There were 10 out of 526 exceedances of the instantaneous maximum. | ||||
| Data Reference: | San Joaquin River SWAMP Monitoring Data - Grassland Bypass | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | Selenium levels for Salt Slough and constructed and re-constructed water supply channels in the Grassland watershed should not exceed 2 ug/L (monthly mean) or 20 ug/L (instantaneous Maximum). | ||||
| Objective/Criterion Reference: | Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Samples were collected at Agatha Canal @ Mallard Road. | ||||
| Temporal Representation: | The samples were collected from October 27, 1995 to October 25, 2007. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program. | ||||
| QAPP Information Reference(s): | |||||