ENTIAT S_T FACILITY Wastewater Treatment Plant, Chelan County, Washington

The ENTIAT S_T FACILITY is a municipal wastewater treatment plant located in Chelan County, Washington, United States. It serves a population of 1,635 residents and operates as part of the region's water infrastructure. The plant is situated near Lake Chelan, a major natural lake in the Cascade Mountains. The plant provides secondary treatment, which is the standard level required by the US Clean Water Act for municipal wastewater. Its designed capacity is 416.39 megaliters per year, with an actual discharge volume of 302.83 megaliters per year. As a facility in Washington State, it operates under the National Pollutant Discharge Elimination System (NPDES) permit program administered by the Washington State Department of Ecology. The treated effluent is discharged into the Lake Chelan watershed, which drains into the Chelan River and ultimately the Columbia River. Lake Chelan is a deep, oligotrophic lake that supports diverse aquatic life and is an important recreational and ecological resource. The plant's secondary treatment helps protect water quality in this sensitive lake environment.

The plant discharges into the Lake Chelan basin, which flows via the Chelan River to the Columbia River. Lake Chelan is a deep, oligotrophic lake known for its clear waters and supports a variety of fish species, including kokanee salmon and lake trout. The downstream Columbia River is a major Pacific Northwest waterway that provides critical habitat for salmon and steelhead. Protecting water quality in this watershed is essential for maintaining aquatic biodiversity and recreational uses.