Winchester S_T Facility Wastewater Treatment Plant, Idaho

The Winchester S_T Facility is a municipal wastewater treatment plant located in Winchester, Idaho, serving a small population of 245 residents. As a secondary treatment plant, it provides biological treatment to remove organic matter and suspended solids, meeting the standard requirements under the U.S. Clean Water Act for communities of this size. The plant's designed capacity is 132.49 megaliters per year, with an annual discharge volume of 109.78 megaliters, indicating it operates below its capacity. Under the National Pollutant Discharge Elimination System (NPDES), plants of this scale are typically permitted by the Idaho Department of Environmental Quality, ensuring compliance with water quality standards for the receiving water body. The treated effluent is discharged into a local waterway that ultimately drains into the Clearwater River basin, which flows into the Snake River and then the Columbia River, reaching the Pacific Ocean. The plant plays a key role in protecting the water quality of these downstream ecosystems, which support diverse aquatic life and recreational activities.

The plant discharges into a tributary of the Clearwater River, which flows into the Snake River and then the Columbia River, eventually reaching the Pacific Ocean. The Clearwater River basin supports important salmon and steelhead runs, making water quality protection critical for these migratory fish species. The plant's secondary treatment helps reduce nutrient and organic loads that could otherwise impact downstream aquatic habitats.