ONAWAY STP - Secondary Wastewater Treatment Plant in Onaway, Michigan

ONAWAY STP is a municipal wastewater treatment facility located in Onaway, a small community in Presque Isle County, Michigan, United States. The plant serves a population of approximately 1,039 residents, reflecting its role as a small-scale treatment facility for the local area. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 492.10 m³/day and an average daily discharge of 378.54 m³/day, the facility operates below its capacity. Under the U.S. Clean Water Act, such plants are regulated through National Pollutant Discharge Elimination System (NPDES) permits, which set effluent limits to protect water quality. The treated effluent is discharged into a local water body, likely a tributary of the Black River or Thunder Bay River, which ultimately flows into Lake Huron. Lake Huron is one of the Great Lakes, a vital freshwater resource supporting diverse aquatic life and providing drinking water for millions. The plant's operations help protect this sensitive ecosystem from nutrient pollution and pathogens.

The plant discharges into a local stream that drains into the Black River or Thunder Bay River system, both of which flow into Lake Huron. Lake Huron is a large freshwater lake with significant ecological importance, supporting fish species such as lake trout and walleye, and providing habitat for migratory birds. The watershed is primarily forested and rural, with low industrial impact, making nutrient management critical to prevent algal blooms in the lake.