Mercer Lagoon Wastewater Treatment Plant, Mercer, North Dakota

Mercer Lagoon is a municipal wastewater treatment facility located in Mercer, North Dakota, United States. The plant serves a small population of 94 residents, reflecting the rural character of the community. It is situated at 200 West Wing Street in McLean County. The plant provides secondary treatment, which is the standard level required under the U.S. Clean Water Act for municipal facilities. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The plant has a designed capacity of 37.85 cubic meters per day, matching its current discharge volume, indicating it operates at full capacity. The treated effluent is discharged into local waterways, contributing to the Missouri River watershed. The plant's operation helps protect downstream aquatic ecosystems by reducing pollutant loads. As a small facility in a rural area, it plays a key role in maintaining local water quality.

The plant discharges into the Missouri River basin, which flows through North Dakota and ultimately into the Mississippi River and the Gulf of Mexico. The local watershed supports diverse aquatic life, including fish species such as walleye and northern pike. Proper treatment is essential to prevent nutrient enrichment and protect downstream habitats.