Comparison of State and Federally Approved Water Quality Standards
Current as of April 18, 2023
Alaska Water Quality Standards (WQS) must be approved by the Environmental Protection Agency (EPA) before they can be used for actions regulated under the federal Clean Water Act (CWA).
Discrepancies between state and federally approved standards arise when:
- Alaska adopts a standard and there is a lag time between when it is approved by EPA, or
- EPA promulgates criteria for Alaska and there is a lag time between when it is promulgated and when Alaska adopts a corresponding standard.
The following table summarizes the differences between 2018 Alaska WQS[1] and federally approved statewide WQS for CWA purposes such as APDES[2] or NPDES[3] wastewater discharge permits, Total Maximum Daily Load (TMDL) allocations, and CWA Section 303(d) impaired waterbody listings.
For actions under state regulation only such as wastewater discharges to groundwater, the 2023 Alaska WQS should be used exclusively.
This summary of regulations has been prepared by the Alaska Department of Environmental Conservation and does not constitute an official version of these regulations, nor does it necessarily reflect current law. If a discrepancy is found between this factsheet and the Alaska Administrative Code (AAC), the AAC should be considered the final authority, unless the discrepancy is the result of a technical error in the Code.
| WQS | State Only Approved Criteria | Federally Approved State Criteria |
|---|---|---|
| Natural conditions (all uses) | November 13, 2022 Alaska WQS (PDF)18 AAC 70.010(d) | 2003 Alaska WQS (PDF)18 AAC 70.235(b) |
| Selenium for use (1)(C) (freshwater aquatic life criteria) | September 8, 2022 Toxics Manual (PDF)18 AAC 70.020(b)(11) | 1999 Alaska WQS (PDF) 18 AAC 70.020(b) Note 5[7]20 μg/L acute (total recoverable)5 μg/L chronic (total recoverable) |
| Carcinogens for uses(1)(A)(i) and (iii),(1)(B)(i) and (ii), (1)(C),(2)(A)(i), (2)(B)(i) and (ii), and (2)(C) and (D) | September 8, 2022 Toxics Manual (PDF) | 40 CFR 131.36 (PDF) |
[1] Alaska Pollutant Discharge Elimination System
[2] National Pollutant Discharge Elimination System
[3] 1999 Alaska WQS refers to the Department of Environmental Conservation document entitled 18 AAC 70 Water Quality Standards as amended through May 27, 1999
[4] Adoption by reference of Ambient Water Quality Criteria for Selenium – 1987, EPA 440/5‐80‐070.
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