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Public Notice: Proposed Discharge Permits for Federal Hydroelectric Projects in the Lower Snake River

Publish Date: 01/15/2021


EPA is proposing to issue National Pollutant Discharge Elimination System (NPDES) permits for four hydroelectric generating facilities on the lower Snake River operated by the United States Army Corps of Engineers:

  • Ice Harbor Lock and Dam (WA0026816).
  • Lower Monumental Lock and Dam (WA0026808).
  • Little Goose Lock and Dam (WA0026786).
  • Lower Granite Lock and Dam (WA0026794).

These permits will address oil and grease discharges, pH, and cooling water discharges from hydroelectric generating facilities. 

On March 18, 2020, EPA proposed for public comment NPDES permits to authorize the discharges from the Lower Snake River Hydroelectric Generating Facilities. The public notice closed on May 4, 2020. The draft permits did not include heat load effluent limits. EPA is proposing changes to the draft permits to include heat load effluent limits and is seeking public comment on these limits.

On May 18, 2020, EPA issued the Lower Columbia and Snake Rivers Temperature TMDL, which included heat load wasteload allocations (WLAs) for the Lower Snake River hydroelectric generating facilities. From May 20, 2020 to August 20, 2020, EPA provided the public an opportunity to comment on the Lower Columbia and Snake Rivers temperature TMDL. During that time, the U.S. Army Corps of Engineers (USACE) submitted new information and analysis and proposed revisions to the heat load WLAs.

EPA is seeking comment on heat load effluent limits based on both the May 2020 WLAs and USACE-proposed WLAs alternatives. EPA is not seeking comment on other effluent limits or provisions in these permits. EPA will consider all comments received in the public comment period from March 18, 2020, to May 4, 2020, and this comment period prior to issuing final permits.

Related permits: Proposed Discharge Permits for Federal Hydroelectric Projects in the Lower Columbia River.

Tentative Determination

The Region 10 office of the EPA has tentatively determined to issue discharge permits to the applicants.

Water Quality Certification

EPA requested final Clean Water Act Section 401 certification of these permits from the Washington Department of Ecology (Ecology) on March 18, 2020. On May 7, 2020, Ecology provided final certifications of these permits under Section 401. One condition in Ecology’s final certifications was a condition to incorporate the wasteload allocations (WLAs) from the Lower Columbia and Snake Rivers Temperature Total Maximum Daily Load (Lower Columbia and Snake Rivers temperature TMDL). These revised draft permits now include the effluent limits that incorporate the WLAs.

Administrative Record

Electronic copies of the draft permits and technical fact sheet are available below under "Related Documents."

Copies and other information may be also requested by contacting Jennifer Wu (, 206-553-6328.

Because of COVID-19 response, there is no public access to the Region 10 EPA building at this time. Therefore, we cannot make hard copies available for viewing at our offices.

Disability Reasonable Accommodation

If you need a reasonable accommodation for a disability, please call Audrey Washington at 206-553-0523 (voice). TTY/TDD users please dial Washington Relay Service at 1-800-833-6388. Please provide one week advance notice for special requests not related to ongoing programs and services.

Applicants or Respondents

Ice Harbor Lock and Dam
2763 Monument Drive
Burbank, WA 99323
Lower Monumental Lock and Dam
5220 Devil’s Canyon Road
Kahlotus, WA 99335
Little Goose Lock and Dam
1001 Little Goose Dam Road
Dayton, WA 99359
Lower Granite Lock and Dam
885 Almota Ferry Road
Pomeroy, WA 99133

Related Documents

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