Cogswell Lagoon Wastewater Treatment Plant, Cogswell, North Dakota

Cogswell Lagoon is a municipal wastewater treatment facility located in Cogswell, Sargent County, North Dakota. It serves a small population of 99 residents, reflecting the rural character of the area. The plant is situated in the northern Great Plains, a region with cold winters and low population density. The plant provides secondary treatment, a standard level for small communities in the United States. With a designed capacity of 75.71 cubic meters per day and an average discharge volume of 37.85 cubic meters per day, it operates well within its capacity. Under the U.S. Clean Water Act, such facilities are regulated through the National Pollutant Discharge Elimination System (NPDES) permit program, which sets effluent limits to protect receiving waters. The treated effluent from Cogswell Lagoon discharges into local streams that are part of the Red River of the North basin, ultimately flowing north into Lake Winnipeg in Canada. This watershed supports agricultural land use and provides habitat for fish and waterfowl. Proper treatment helps maintain water quality in this transboundary river system.

The plant's effluent enters small tributaries of the Red River of the North, which flows northward through North Dakota and Manitoba into Lake Winnipeg. This watershed is ecologically significant as a migratory corridor for birds and supports diverse aquatic life. The region's flat terrain and agricultural runoff make nutrient management important for preventing eutrophication in downstream waters.