| Pollutant: |
Specific Conductivity |
| 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: |
Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available |
| |
| 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. |
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| State Board Review of Regional Board Conclusion and Recommendation: |
|
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| State Board Decision Recommendation: |
After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded. |
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Line of Evidence (LOE) for Decision ID 162998, Specific Conductivity
|
Region 1 |
Cape Mendocino HU, Capetown HA, Bear River |
|
| |
| LOE ID: |
318715 |
| |
| Pollutant: |
Specific Conductivity |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
Total |
| |
| Beneficial Use: |
Cold Freshwater Habitat |
| |
| Number of Samples: |
1 |
| Number of Exceedances: |
1 |
| |
| Data and Information Type: |
PHYSICAL/CHEMICAL MONITORING |
| Data Used to Assess Water Quality: |
Water Board staff assessed specific conductivity data for USGS California Water Science Center and determined that calendar year 2015 exceeds both the 90% and 50% upper limits, so that 1 of 1 sample exceeds the water quality objective. |
| Data Reference: |
WQX from the NWQMP for the 2026 Integrated Report in Region 1 |
| |
| SWAMP Data: |
Non-SWAMP |
| |
| Water Quality Objective/Criterion: |
Per the Basin Plan (NCRWQCB 2007): The 90% upper limit specific conductance objective at 77 F is350 micromhos (or mS/cm2). The 50% upper limit specific conductance objective at 77 F is 150 micromhos (or mS/cm2). The 90% and 50% upper limits represent the 90/50 percentile values for a calendar year. 90% or 50% or more of the values must be less than or equal to the upper limit. |
| Objective/Criterion Reference: |
Water Quality Control Plan (Basin Plan) for the North Coast Region |
| |
| Evaluation Guideline: |
|
| Guideline Reference: |
| |
| Spatial Representation: |
This sample was collected at sampling station name: BEAR R A CAPETOWN CA; station code: USGS-11469550. |
| Temporal Representation: |
This sample was collected on 8/24/2015. |
| Environmental Conditions: |
|
| QAPP Information: |
QAPP for USGS California Water Science Center |
| QAPP Information Reference(s): |
QAPP for USGS Data Collected during the 2026 Integrated Report Cycle |
| |
| Pollutant: |
Temperature, water |
| 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: |
Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. |
| |
| 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. |
| |
| State Board Review of Regional Board Conclusion and Recommendation: |
|
| |
| State Board Decision Recommendation: |
|
| |
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Line of Evidence (LOE) for Decision ID 158682, Temperature, water
|
Region 1 |
Cape Mendocino HU, Capetown HA, Bear River |
|
| |
| LOE ID: |
329284 |
| |
| Pollutant: |
Temperature, water |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
None |
| |
| Beneficial Use: |
Cold Freshwater Habitat |
| |
| Number of Samples: |
1 |
| Number of Exceedances: |
1 |
| |
| Data and Information Type: |
PHYSICAL/CHEMICAL MONITORING |
| Data Used to Assess Water Quality: |
Water Board staff assessed USGS California Water Science Center data for Cape Mendocino HU, Capetown HA, Bear River to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature. |
| Data Reference: |
WQX from the NWQMP for the 2026 Integrated Report in Region 1 |
| |
| SWAMP Data: |
Non-SWAMP |
| |
| Water Quality Objective/Criterion: |
Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. At no time or place shall the temperature of any COLD water be increased more than 5 degrees Fahrenheit (F) above natural receiving water temperature (Basin Plan, North Coast Region). |
| Objective/Criterion Reference: |
Water Quality Control Plan (Basin Plan) for the North Coast Region |
| |
| Evaluation Guideline: |
According to Carter (2008) the lethal temperature evaluation guideline for salmonid spawning, egg incubation & fry emergence is 20C. |
| Guideline Reference: |
Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region |
| |
| Spatial Representation: |
The samples were collected at 1 monitoring site: USGS-11469550 (BEAR R A CAPETOWN CA). |
| Temporal Representation: |
The samples were collected between the dates of 2015-08-24 and 2015-08-24 |
| Environmental Conditions: |
|
| QAPP Information: |
QAPP not required for USGS projects |
| QAPP Information Reference(s): |
QAPP for USGS Data Collected during the 2026 Integrated Report Cycle |
| |