Shannock Valley Numine STP - Advanced Wastewater Treatment in Cowanshannock Township, Pennsylvania

Shannock Valley Numine STP is an advanced wastewater treatment facility located in Cowanshannock Township, Armstrong County, Pennsylvania. The plant serves a population of approximately 1,722 residents and has a designed capacity of 832.79 cubic meters per day, with an average discharge volume of 757.08 cubic meters per day. As a US facility, it operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permitting, which sets effluent limits to protect water quality. The plant's advanced treatment level indicates it goes beyond secondary treatment to remove nutrients or other pollutants, reflecting the regulatory requirements for sensitive watersheds. The treated effluent is discharged to a local receiving water body, which ultimately drains into the Allegheny River watershed. The Allegheny River flows into the Ohio River, then the Mississippi River, and finally the Gulf of Mexico. The plant's location in a rural area of Pennsylvania means its discharge supports local stream health and downstream aquatic ecosystems, contributing to the overall water quality of the region.

The plant discharges into a tributary of the Allegheny River, which flows through western Pennsylvania before joining the Ohio River. The Allegheny River watershed supports diverse aquatic life, including several species of freshwater mussels and fish. Downstream, the Ohio and Mississippi Rivers carry the water to the Gulf of Mexico, where nutrient loads can contribute to hypoxic zones. The plant's advanced treatment helps reduce nutrient pollution, protecting both local streams and the broader Gulf ecosystem.