| Water Body Name: | Thoms Creek (Modoc County) |
| Water Body ID: | CAR5265201520090108162222 |
| Water Body Type: | River & Stream |
DECISION ID |
10390 |
Region 5 |
Thoms Creek (Modoc County) |
||
| Pollutant: | Escherichia coli (E. coli) |
| 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 |
| Regional Board Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status.
Two lines of evidence are available in the administrative record to assess this pollutant. One 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. One of 10 available concentrations exceeded the USEPA E. coli Objective for Water Contact Recreation and this does not exceed the allowable frequency using Table 3.2 of the Listing Policy. In addition, 1 of 10 available concentrations exceeded the USEPA E. coli Objective for Non-Contact Recreation and this does not exceed the allowable frequency using 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 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 decision be approved by the State Board. |
| USEPA Action (if applicable): | |
|
|||||
| LOE ID: | 21032 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Non-Contact Recreation | ||||
| Number of Samples: | 10 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | 1 of the 10 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for E.Coli Bacteria. The exceeded results are as follows: 6/23/2004 - a sample taken at Lower Thomas Creek had a result of 1200MPN/100 mL. | ||||
| Data Reference: | SWAMP data entered by SWRCB into BDAT database | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CRWQCB, 2006) | ||||
| 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: | E.Coli Bacteria levels should not exceed 409 MPN/100 mL in any single sample (USEPA E.Coli Guideline) | ||||
| Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002 | ||||
| Spatial Representation: | Samples were collected at Lower Thomas Creek. Samples were collected at Upper Thomas/Thomas Creek. | ||||
| Temporal Representation: | The samples were collected from May 20 2004 to Jan 20 2005 | ||||
| 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): | |||||
|
|||||
| LOE ID: | 21031 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 10 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | 1 of the 10 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for E.Coli Bacteria. The exceeded results are as follows: 6/23/2004 - a sample taken at Lower Thomas Creek had a result of 1200MPN/100 mL. | ||||
| Data Reference: | SWAMP data entered by SWRCB into BDAT database | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CRWQCB, 2006) | ||||
| 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: | E.Coli Bacteria levels should not exceed 235 MPN/100 mL in any single sample (USEPA E.Coli objective) | ||||
| Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002 | ||||
| Spatial Representation: | Samples were collected at Lower Thomas Creek. Samples were collected at Upper Thomas/Thomas Creek. | ||||
| Temporal Representation: | The samples were collected from May 20 2004 to Jan 20 2005 | ||||
| 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 |
9781 |
Region 5 |
Thoms Creek (Modoc County) |
||
| Pollutant: | pH |
| 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 |
| Regional Board Conclusion: | This pollutant is being considered for listing under sections 3.2 of the Listing Policy. Under section 3.2 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 1 of 20 available concentrations exceeded the water quality objective and this does not exceed the allowable frequency using Table 3.2 of the Listing Policy. Table 3.2 of the listing policy recommends listing if a sample size of 20 has 5 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 decision be approved by the State Board. |
| USEPA Action (if applicable): | |
|
|||||
| LOE ID: | 21047 | ||||
| Pollutant: | pH | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Cold Freshwater Habitat | ||||
| Aquatic Life Use: | Cold Freshwater Habitat | ||||
| Number of Samples: | 20 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | 1 of the 20 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for pH. | ||||
| Data Reference: | SWAMP data entered by SWRCB into BDAT database | ||||
| 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 Lower Thomas Creek. Samples were collected at Upper Thomas/Thomas Creek. | ||||
| Temporal Representation: | The samples were collected from Sep 22 2003 to Jan 20 2005 | ||||
| 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): | |||||