CHELSEA STP Wastewater Treatment Plant, Chelsea, Michigan

CHELSEA STP is a municipal wastewater treatment plant located in Chelsea, Washtenaw County, Michigan. It serves a population of approximately 5,001 residents, placing it in the small-to-medium agglomeration category. The plant is situated inland, away from coastal areas, and its operations are part of the regional water infrastructure. As a US-based facility, CHELSEA STP operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Michigan Department of Environment, Great Lakes, and Energy (EGLE). For plants serving around 5,000 people, secondary treatment is typically required to meet effluent standards. The regulatory framework ensures compliance with water quality standards. The plant discharges treated wastewater into a local water body that ultimately drains into the Huron River watershed, which flows into Lake Erie via the Detroit River. This connection to the Great Lakes system underscores the importance of effective treatment to protect downstream aquatic ecosystems and drinking water sources.

CHELSEA STP discharges into a tributary of the Huron River, which flows through southeastern Michigan before joining the Detroit River and eventually Lake Erie. The Huron River watershed supports diverse aquatic life, including fish species such as smallmouth bass and walleye, and provides habitat for migratory birds. The plant's location inland and upstream of the Great Lakes means that its effluent quality directly affects the ecological health of the river system and the larger lake ecosystem.