Derry Borough STP: Wastewater Treatment in Derry, Pennsylvania

Derry Borough STP is a municipal wastewater treatment facility located in Derry, Westmoreland County, Pennsylvania. Serving a population of about 2,991, the plant is part of the region's infrastructure for managing domestic wastewater from this small borough in the Laurel Highlands area. As a US facility, the plant operates under the National Pollutant Discharge Elimination System (NPDES) permit program, which is authorized by the Clean Water Act. For small communities like Derry, secondary treatment is typically required to meet effluent limits that protect water quality. The plant's design and operation are overseen by the Pennsylvania Department of Environmental Protection. The treated effluent from Derry Borough STP is discharged into a local waterway that ultimately drains into the Ohio River basin. The receiving waters support aquatic life and are part of the larger Mississippi River watershed, which flows into the Gulf of Mexico. Protecting these waters is important for regional ecology and downstream communities.

The plant's discharge enters a tributary of the Ohio River, which flows into the Mississippi River and eventually the Gulf of Mexico. This watershed supports diverse aquatic species and is used for recreation and drinking water. The plant's treatment helps reduce nutrient and pollutant loads, protecting downstream ecosystems from eutrophication and contamination.