The Washington State Department of Ecology (Ecology) is proposing to revise the state surface water quality criteria for temperature In rivers, lakes, and reservoirs.
Water temperature is a vital factor influencing the health and survival of native fish. Each species in the aquatic community responds differently to water temperature. Thus, temperature plays a large part in determining the health of aquatic communities.
Temperature affects embryonic development, juvenile growth, adult migration, competition with non-native species, and influences the relative risk and severity of disease. Concerns about the temperature standards vary. Some people have suggested the existing standards are unnecessarily stringent, others believe the standards are not cold enough to protect native salmon.
In an effort to respond to these concerns, Ecology conducted a detailed review of the technical literature and the merits of the existing criteria. With one exception, we found that the existing criteria only needed minor revision to be brought up to date with the current fisheries research and to meet the demands of the federal Endangered Species Act. The one exception is bull trout, where the existing standards were found to be significantly inadequate to protect the tributary spawning and rearing areas of the endangered cold water species. In addition to setting criteria to protect specific species and their life-stages, the proposal includes a limit on how hot a discharge of wastewater can be to prevent the instant death of fish swimming through the discharged wastewater.
| Current Water Quality Criteria for Temperature | |||
| Key Species or Life-Stage Protected | 1-Day Maximum | 7-Day Average of Daily Maximums | 21-Day Average |
| Class AA (Extraordinary Salmon Spawning) | 16-C (60.8-F) | ||
| Class A (Excellent Salmon Spawning) | 18-C (64.4F) | ||
| Class B (Salmon Rearing) | 21-C (68F) | ||
| Lakes and Reservoirs | No change from natural levels |
| Proposed Water Quality Criteria for Temperature | |||
| Key Species or Life-Stage Protected | I-Day Maximum | 7-Day Average of Daily Maximums | 21-Day Average |
| Bull Trout and Dolly Varden Char | 11.5-C (52.7F) | ||
| Spawning of Salmon, Steelhead, and Trout | 13-C (55.4-F) | 9-C (48.2-F) | |
| Rearing of Salmon, Steelhead, and Trout | 17-C (62.6-F) | 14-C (57.2F) | |
| Rearing of Redband Trout | 18-C (64.4-F) | 16-C (60.8-F) | |
| Warm Water Fish | 25-C (77-F) | 20-C (68-F) | |
| Mixing Zone Temp. Limit | 33-C (91.4F) |
Over the past two years, Ecology - along with Oregon, Idaho, the tribes, and federal agencies has participated with the U.S. Environmental Protection Agency (EPA) to develop temperature criteria suitable for our entire region. While Washington State's recommendations have been informed by our participation in the larger regional process, the two efforts at this point are still somewhat different. Ecology will carefully consider the final EPA criteria guidance as well as public comments on the EPA guidance before making any formal changes to the state's temperature criteria.
Please visit our website at www.ecy.wa.gov/programs/wq/swqs for more information. To obtain copies of any of the focus sheets or discussion documents or to be added to the mailing list, contact Ann Kahler at (360) 407-6404.
The Department of Ecology will hold public hearings before adopting any of the proposed changes. Hearings are currently anticipated for the spring of 2002. If you have submitted your name to either our mailing list or our e-mail list serve, we will directly notify you of the dates and locations of the upcoming public hearings. If you have e-mail and would like to receive electronic updates on the water quality standards revisions, please send a message to swqs&ecy.wa.gov with "Subscribe" as the subject heading.
If you have any comments on the proposed changes to the water quality standards, please contact:
| Mark Hicks | Department of Ecology | E-mail: mhic461@ecy.wa.gov |
| PO Box 47600 | (360) 407-6477 | |
| Olympia WA 98505-7600 | (360) 407-6006 (TDD) |
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