PLENTYWOOD LAGOON Wastewater Treatment Plant, Sheridan County, Montana

PLENTYWOOD LAGOON is a municipal wastewater treatment facility located in Sheridan County, Montana, United States. The plant serves a population of approximately 1,853 residents, reflecting its role as a small-scale community infrastructure asset in the rural northern plains region. The plant provides secondary treatment, which is the standard biological treatment stage required under the U.S. Clean Water Act for municipal wastewater. Secondary treatment typically involves biological oxidation and settling to reduce organic matter and suspended solids. The plant's designed capacity is 1063.70 units, with a current discharge volume of 700.30 units, indicating operational headroom. The treated effluent from PLENTYWOOD LAGOON is discharged into the local watershed, which ultimately drains into the Missouri River basin. This water body supports regional aquatic life and agricultural water use. The plant's operation is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Montana Department of Environmental Quality, ensuring compliance with federal water quality standards.

The plant discharges into the Missouri River watershed, which flows into the Mississippi River and eventually the Gulf of Mexico. This basin supports diverse aquatic species and provides irrigation water for agriculture. The plant's secondary treatment helps protect downstream water quality by reducing nutrient and organic loads, which is critical in this semi-arid region where water resources are limited.