Cusick Wastewater Treatment Plant - Small Municipal Facility in Washington

The Cusick Wastewater Treatment Plant is a municipal facility located in Cusick, a small town in Pend Oreille County, Washington, United States. It serves a population of 360 people, reflecting its role as a small-scale treatment system in a rural setting. The plant provides secondary treatment, which is the standard level required under the U.S. Clean Water Act for municipal wastewater facilities. With a designed capacity of 264.98 megaliters and an annual discharge volume of 227.13 megaliters, the plant operates within its capacity. As a U.S. facility, it operates under a National Pollutant Discharge Elimination System (NPDES) permit issued by the Washington State Department of Ecology, ensuring compliance with federal water quality standards. The plant's treated effluent is discharged into the local watershed, which ultimately drains into the Pend Oreille River, a tributary of the Columbia River. The Columbia River system supports diverse aquatic life and is a critical resource for the Pacific Northwest, including salmon runs and other native species. The plant's secondary treatment helps protect downstream water quality in this ecologically significant basin.

The plant discharges into the Pend Oreille River basin, which flows into the Columbia River, the largest river in the Pacific Northwest. The Columbia River system supports critical salmon and steelhead runs, as well as diverse aquatic ecosystems. Secondary treatment reduces organic pollutants and suspended solids, helping to maintain water quality in this important migratory corridor.