Priest River STP - Blanchard, Idaho Wastewater Treatment Plant

Priest River STP is a municipal wastewater treatment plant located in Blanchard, Idaho, serving a population of 1,751. The facility provides secondary treatment, a standard level for small communities in the United States, ensuring compliance with Clean Water Act requirements. The plant has a designed capacity of 946.35 volume units and a current discharge volume of 855.50, indicating it operates below capacity. As a US facility, it is regulated under the National Pollutant Discharge Elimination System (NPDES), which sets effluent limits to protect water quality. The treated effluent is discharged into a local water body that drains into the Priest River system, part of the Pend Oreille River basin, ultimately reaching the Columbia River and the Pacific Ocean. The plant plays a key role in protecting downstream aquatic habitats and recreational waters.

The plant discharges into the Priest River watershed, which flows into the Pend Oreille River, a major tributary of the Columbia River. This river system supports diverse fish populations, including salmon and trout, and provides critical habitat for migratory birds. The secondary treatment process helps reduce nutrient and pathogen loads, safeguarding water quality in this ecologically sensitive region.