Heyburn State Park S_T FA Wastewater Treatment Plant, Benewah County, Idaho

Heyburn State Park S_T FA is a wastewater treatment plant located in Benewah County, Idaho, United States. It serves a population of approximately 192,882 people, making it a large agglomeration under US EPA guidelines. The plant operates as part of the municipal wastewater infrastructure for the region. The plant provides secondary treatment, which is the standard level required by the US Clean Water Act for most municipal facilities. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The plant has a designed capacity of 193.06 million gallons per day and currently discharges 37.85 million gallons per day, indicating it operates well below its capacity. The treated effluent is discharged into the local watershed, which ultimately drains into the Spokane River and then the Columbia River system. The Columbia River basin supports diverse aquatic life and is an important ecological corridor in the Pacific Northwest. The plant's location inland and away from the coast reduces direct marine impact, but its discharge still affects freshwater ecosystems.

The plant's treated effluent enters the local watershed, which flows into the Spokane River and eventually the Columbia River, a major river system in the Pacific Northwest. The Columbia River basin supports salmon runs, steelhead, and other native fish species, making water quality management critical. The plant's secondary treatment helps reduce pollutants before discharge, protecting downstream aquatic habitats.