MSD Polk Run Drainage Basin Wastewater Treatment Plant, Twightwee, Ohio

MSD Polk Run Drainage Basin is a wastewater treatment facility located in Twightwee, Ohio, serving a population of about 26,400 residents. It operates under the Metropolitan Sewer District of Greater Cincinnati, which manages wastewater infrastructure across Hamilton County. The plant is situated in the suburban community of Twightwee, part of Symmes Township, and plays a key role in managing local sewage and stormwater. As a medium-sized agglomeration, the plant is subject to the U.S. Clean Water Act and National Pollutant Discharge Elimination System (NPDES) permitting requirements. Facilities serving populations between 10,000 and 100,000 typically require secondary treatment as a minimum standard. The plant's treatment processes are designed to meet state and federal effluent limits to protect water quality in the receiving streams. The plant's treated effluent discharges into local tributaries that flow into the Little Miami River, a National Scenic River, and ultimately into the Ohio River. The Ohio River is a major waterway that supports diverse aquatic life, provides drinking water for millions, and is an important industrial and recreational resource. Protecting this watershed is critical for downstream communities and ecosystems.

The plant discharges into streams within the Little Miami River watershed, which flows into the Ohio River. The Ohio River is a major tributary of the Mississippi River, draining into the Gulf of Mexico. The Little Miami River is recognized for its ecological significance, supporting diverse fish and macroinvertebrate populations. The plant's operations help maintain water quality in this sensitive watershed, which is used for recreation and as a drinking water source.