La Conner Treatment Wastewater Plant, La Conner, Washington

La Conner Treatment is a municipal wastewater facility located in La Conner, Washington, United States. It serves a small population of 1,115 residents, reflecting the scale of this rural community in Skagit County. The plant's location near the Swinomish Channel and Skagit Bay places it in a coastal environment. The plant provides secondary treatment, a standard level for small communities under the U.S. Clean Water Act. Its designed capacity is 870.64 thousand cubic meters per year, with an actual discharge volume of 567.81 thousand cubic meters, indicating operational headroom. As a U.S. facility, it operates under an EPA NPDES permit issued by the Washington State Department of Ecology, which sets effluent limits to protect water quality. The treated effluent discharges into the Swinomish Channel, which flows into Skagit Bay and ultimately the Puget Sound. This estuarine environment supports diverse aquatic life, including salmon runs and shellfish beds. The plant's coastal proximity requires careful nutrient and pathogen control to prevent eutrophication and protect marine habitats.

The plant discharges into the Swinomish Channel, a tidal estuary connecting to Skagit Bay and the greater Puget Sound. This watershed supports critical salmonid habitats and shellfish harvesting areas. Coastal discharge requires compliance with stringent water quality standards to protect the sensitive marine ecosystem from nutrient loading and pathogens.