Coulee Dam S_T FAC Wastewater Treatment Plant, Coulee Dam, Washington

Coulee Dam S_T FAC is a municipal wastewater treatment facility located in Coulee Dam, Washington, serving a population of approximately 2,138 residents. The plant is situated in Okanogan County and provides secondary treatment, a standard level for communities of this size under the US Clean Water Act. The facility has a designed capacity of 1,741.28 megaliters and treats an annual discharge volume of 946.35 megaliters. As a secondary treatment plant, it uses biological processes to remove organic matter and suspended solids before discharge. The plant operates under the National Pollutant Discharge Elimination System (NPDES) permit program, which sets effluent limits to protect water quality. The treated effluent is discharged into the Columbia River basin, which flows through the Pacific Northwest and ultimately reaches the Pacific Ocean. The plant plays a key role in protecting the local watershed, including the Columbia River, which supports diverse aquatic life and provides water for irrigation, recreation, and hydropower.

The plant discharges into the Columbia River basin, a major river system that drains into the Pacific Ocean. The Columbia River supports salmon runs, steelhead, and other native fish species, making water quality critical for ecological health. The plant's secondary treatment helps reduce nutrient and pollutant loads, protecting downstream habitats in the river and estuary.