Fort Benton Lagoons Wastewater Treatment Plant, Montana

Fort Benton Lagoons is a municipal wastewater treatment facility located in Fort Benton, Montana, along Lagoon Service Road. The plant serves a population of approximately 1,464 residents in this rural community along the Upper Missouri River. As a lagoon-based system, it provides secondary treatment to meet state and federal water quality standards. The plant has a designed capacity of 609.45 volume units and discharges an average of 552.67 volume units, indicating it operates below its design capacity. Under the U.S. Clean Water Act, the facility is subject to National Pollutant Discharge Elimination System (NPDES) permitting, which sets effluent limits to protect receiving waters. Secondary treatment is the minimum standard for municipal plants in the United States, ensuring removal of organic matter and suspended solids. The treated effluent is discharged into the Missouri River watershed, which flows eastward to join the Mississippi River and ultimately the Gulf of Mexico. This stretch of the Missouri River supports diverse aquatic life, including native fish species such as pallid sturgeon and paddlefish. The plant's location in a semi-arid region means that maintaining water quality in the river is critical for downstream ecosystems and agricultural users.

The plant discharges into the Missouri River basin, part of the larger Mississippi River system that drains into the Gulf of Mexico. The Upper Missouri River in Montana supports a cold-water fishery and provides habitat for species like the endangered pallid sturgeon. Downstream, the river flows through agricultural and natural landscapes, where nutrient loading from wastewater can contribute to algal blooms and hypoxic zones in the Gulf.