ASHLAND LAGOONS Wastewater Treatment Plant, Ashland, Montana

ASHLAND LAGOONS is a municipal wastewater treatment facility located in Ashland, Montana, a small community in Rosebud County. The plant serves a population of about 1,100 residents and operates as a lagoon system providing secondary treatment. As a secondary treatment facility, ASHLAND LAGOONS meets the standard requirements under the U.S. Clean Water Act for municipal wastewater treatment. The plant's designed capacity is 238.48 m³/day, with an average discharge volume of 579.17 m³/day, indicating it handles flows above its nominal capacity. The plant is regulated under the National Pollutant Discharge Elimination System (NPDES) permitting program, which sets effluent limits to protect water quality. The treated effluent from ASHLAND LAGOONS is discharged into a local waterway within the Tongue River watershed, which eventually flows into the Yellowstone River and then the Missouri River system. This region supports diverse aquatic life and is part of the larger Mississippi River drainage basin. The plant's operation is critical for protecting downstream water quality in this semi-arid region.

The plant discharges into a tributary of the Tongue River, which flows into the Yellowstone River, a major tributary of the Missouri River. This watershed supports a variety of fish species, including cold-water fisheries, and provides habitat for migratory birds. The semi-arid climate of southeastern Montana makes water quality management particularly important for maintaining ecosystem health and agricultural uses downstream.