Lakeside STP - Secondary Wastewater Treatment Plant in Lakeside, Montana

Lakeside STP is a municipal wastewater treatment facility located in Lakeside, Montana, serving a population of approximately 1,914 residents. The plant provides secondary treatment, a standard level for communities of this size in the United States, ensuring compliance with federal and state water quality standards. The plant has a designed capacity of 757.08 megaliters and discharges an annual volume of 529.96 megaliters. As a U.S. facility, it operates under the National Pollutant Discharge Elimination System (NPDES) permit program, which sets effluent limits to protect receiving waters. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into a local water body that ultimately drains into Flathead Lake, one of the largest natural freshwater lakes in the western United States. Flathead Lake supports diverse aquatic life and is a key recreational and ecological resource in the Flathead River Basin.

The plant's discharge enters a tributary of Flathead Lake, which is part of the Columbia River Basin. Flathead Lake is known for its clear waters and supports native fish species such as bull trout and westslope cutthroat trout. The lake's ecological health depends on careful nutrient management to prevent algal blooms, making the plant's secondary treatment and NPDES permit compliance critical for downstream water quality.