Greenville STP Wastewater Treatment Plant, Hempfield Township, Pennsylvania

Greenville STP is a municipal wastewater treatment plant located in Hempfield Township, Mercer County, Pennsylvania. The facility serves a population of about 12,140 residents in the Greenville area. As a US-based plant serving a medium-sized community, Greenville STP operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Pennsylvania Department of Environmental Protection. These permits set effluent limits to protect water quality. The plant discharges treated wastewater into a local waterway that ultimately drains into the Shenango River, part of the Beaver River watershed, which flows into the Ohio River and then the Mississippi River system. The facility plays a key role in protecting downstream aquatic ecosystems.

The plant discharges into a tributary of the Shenango River, which flows into the Beaver River, a major tributary of the Ohio River. This watershed supports diverse aquatic life and provides drinking water for downstream communities. The Ohio River basin is ecologically significant, hosting numerous fish species and migratory birds. Proper treatment at Greenville STP helps prevent nutrient pollution and maintains water quality in this interconnected river system.