LEWISTON S_T PLANT - Municipal Wastewater Treatment in Lewiston, Idaho

The LEWISTON S_T PLANT is a municipal wastewater treatment facility located at 733 12th Street North in Lewiston, Idaho. Serving an estimated population of 34,068, the plant is part of the city's essential water infrastructure in Nez Perce County. As a US facility, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Idaho Department of Environmental Quality. For a community of this size, secondary treatment is typically required, with possible additional nutrient controls depending on the receiving water body's sensitivity. The plant's treated effluent is discharged into the Snake River, a major tributary of the Columbia River. The Snake River supports diverse aquatic life, including salmon and steelhead runs, and flows through the Columbia River Gorge before reaching the Pacific Ocean. The plant's discharge quality is critical for maintaining downstream water quality and ecosystem health.

The plant discharges into the Snake River, which flows into the Columbia River and ultimately the Pacific Ocean. This watershed supports important fish populations, including threatened and endangered species. The region's semi-arid climate and agricultural land use make water quality management essential for both ecological and human uses.