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NPDES Permit for Chief Joseph Dam in Washington

Below is EPA's National Pollutant Discharge Elimination System (NPDES) permit and supporting documents for the U.S. Army Corps of Engineers Chief Joseph Dam discharging to the Columbia River in Washington and on the Confederated Tribes of the Colville Reservation.

Permit number: WA0026891
Effective date: December 1, 2023
Permit expires: November 30, 2028

NPDES Permit, Chief Joseph Dam, #WA0026891 (pdf) (384.37 KB, May 18, 2023)
Final discharge permit.
NPDES Permit Fact Sheet, Chief Joseph Dam, #WA0026891 (pdf) (2.49 MB, January 2022)
Technical basis for permit.
Response to Comments on Draft NPDES Permit for Chief Joseph Dam, #WA0026891 (pdf) (488.38 KB, May 2023)
EPA's responses to public comments on the January 2022 draft permit.
Confederated Tribes of the Colville Reservation Clean Water Act 401 Certification for NPDES Permits #WA0026891 and #WA0026867 (pdf) (389.42 KB, September 29, 2022)
Water quality certification for discharges to tribal waters.
Washington Dept. of Ecology Clean Water Act Section 401 Certification for NPDES Permit #WA0026891 (pdf) (329.47 KB, September 30, 2022)
Water quality certification for discharges to state waters.