Southside Sewer System Wastewater Treatment Plant, Bonner County, Idaho

Southside Sewer System is a municipal wastewater treatment facility located on Lakeshore Drive in Bonner County, Idaho, serving a population of approximately 1,253 residents. The plant operates under the regulatory framework of the U.S. Clean Water Act, which requires secondary treatment for municipal wastewater to protect water quality. As a small-scale facility, it plays a key role in managing local wastewater in this rural area of northern Idaho. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 340.69 thousand gallons per day and a current discharge volume of 264.98 thousand gallons per day, the facility operates below its capacity, indicating room for future growth. The plant is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Idaho Department of Environmental Quality, ensuring compliance with federal and state water quality standards. The treated effluent is discharged into the local watershed, which ultimately drains into the Pend Oreille River and then to the Columbia River system, reaching the Pacific Ocean. This water body supports diverse aquatic life and is important for regional ecology. The plant's operations help protect downstream water quality in this sensitive inland watershed.

The plant discharges into the local watershed that feeds the Pend Oreille River, a major tributary of the Columbia River system. The Columbia River basin supports critical salmon runs and diverse aquatic habitats. The plant's secondary treatment reduces organic pollutants and suspended solids, helping to maintain water quality in this ecologically important region.