Smyrna STP - Wastewater Treatment Plant in Smyrna, Tennessee

Smyrna STP is a wastewater treatment facility serving the town of Smyrna in Rutherford County, Tennessee. The plant handles wastewater from a population of about 30,000, placing it in the medium-agglomeration category typical of suburban communities in the southeastern United States. Under the U.S. Clean Water Act, plants of this scale are required to meet secondary treatment standards through National Pollutant Discharge Elimination System (NPDES) permits issued by the state. The Tennessee Department of Environment and Conservation oversees compliance, ensuring effluent limits protect local water quality. The plant discharges into the local watershed, which drains into the Stones River, a tributary of the Cumberland River. The Cumberland River flows into the Ohio River and ultimately the Mississippi River, making the plant's operations relevant to downstream ecosystems in the Gulf of Mexico.

The plant's discharge enters the Stones River watershed, which flows into the Cumberland River, a major tributary of the Ohio River. The Cumberland River supports diverse aquatic life, including several species of freshwater mussels and fish. Downstream, the Ohio River joins the Mississippi River, contributing to the nutrient dynamics of the Gulf of Mexico. The region's moderate climate and urban-suburban land use influence runoff patterns and treatment demands.