Calvert City STP - Wastewater Treatment Plant in Calvert City, Kentucky

Calvert City STP is a municipal wastewater treatment facility located in Calvert City, Marshall County, Kentucky. The plant serves a population of about 4,000 people, reflecting a small to medium-sized community in the western part of the state. As a U.S. facility, the plant is subject to the Clean Water Act and National Pollutant Discharge Elimination System (NPDES) permitting, administered by the Kentucky Division of Water. For a plant of this scale, secondary treatment is typically required, with possible additional nutrient removal if discharging into sensitive waters. The plant's treated effluent ultimately reaches the Tennessee River, a major tributary of the Ohio River, which flows into the Mississippi River and the Gulf of Mexico. This downstream connection places the plant within a large, ecologically significant river basin that supports diverse aquatic life and provides drinking water for millions.

The plant discharges into the Tennessee River watershed, which flows into the Ohio River and then the Mississippi River before reaching the Gulf of Mexico. This river system supports a variety of fish and wildlife, including several species of freshwater mussels and migratory birds. The Tennessee River is also a source of drinking water and recreation for downstream communities.