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NPDES Permit for Grand Coulee Dam in Washington

Below is EPA's National Pollutant Discharge Elimination System (NPDES) permit and supporting documents for the U.S Bureau of Reclamation Grand Coulee Dam discharging to the Columbia River in Washington and on the Confederated Tribes of the Colville Reservation.

Permit number: WA0026867
Effective date: December 1, 2023
Modified: December 19, 2024
Permit expires: November 30, 2028

NPDES Permit, Grand Coulee Dam, #WA0026867 (pdf) (584.57 KB, December 19, 2024)
Modified final discharge permit.
NPDES Permit Fact Sheet, Grand Coulee Dam, #WA0026867 (pdf) (919.49 KB, January 2022)
Technical basis for permit.
Response to Comments on Draft NPDES Permit for Grand Coulee Dam, #WA0026867 (pdf) (366.55 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 #WA0026867 (pdf) (290.27 KB, September 30, 2023)
Water quality certification for discharges to state waters.

Related permits: NPDES Permit for Grand Coulee Dam Wastewater Treatment Plant (WA0024163)