Decaturville STP - Secondary Wastewater Treatment Plant in Decaturville, Tennessee

Decaturville STP is a municipal wastewater treatment facility located at 967 Largo Road in Decaturville, Tennessee, within Decatur County. The plant serves a small population of approximately 900 residents, reflecting its role in a rural community in the West Tennessee region. The plant provides secondary treatment, a standard level required under the U.S. Clean Water Act for facilities of this scale. With a designed capacity of 870.64 million gallons and an annual discharge volume of 511.03 million gallons, the plant operates within its capacity. As a U.S. facility, it is regulated under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Tennessee Department of Environment and Conservation. The plant's proximity to the coast (within 10 km) means its treated effluent ultimately reaches the Gulf of Mexico via the Tennessee River and Mississippi River systems. This coastal discharge contributes to the nutrient load in the Gulf, where nitrogen and phosphorus can contribute to hypoxia and algal blooms. The plant's secondary treatment helps reduce organic pollutants but may not fully address nutrient removal, which is a concern for downstream aquatic ecosystems.

The plant's treated effluent flows into local waterways that drain into the Tennessee River, a major tributary of the Ohio and Mississippi Rivers, eventually reaching the Gulf of Mexico. This coastal connection places the plant within a watershed that influences the Gulf's hypoxic zone, where nutrient pollution from inland sources contributes to seasonal dead zones. The plant's secondary treatment reduces biochemical oxygen demand and suspended solids but does not specifically target nutrient removal, which is a key factor in downstream eutrophication.