MARIANNA STP - Advanced Wastewater Treatment in West Bethlehem Township, Pennsylvania

MARIANNA STP is a municipal wastewater treatment facility located in West Bethlehem Township, Washington County, Pennsylvania. The plant serves a population of approximately 1,576 residents, classifying it as a small-scale treatment facility within the state's wastewater infrastructure. The plant employs advanced treatment processes, exceeding the secondary treatment standard required by the U.S. Clean Water Act. With a designed capacity of 1,162.12 million gallons per year and an actual discharge volume of 405.04 million gallons per year, the facility operates well below its capacity, indicating room for future growth or seasonal variability. The treated effluent from MARIANNA STP is discharged into local waterways that ultimately drain into the Ohio River basin. The plant's advanced treatment helps protect downstream water quality in the region, supporting aquatic life and recreational uses in the watershed.

The plant discharges into tributaries of the Ohio River, which flows into the Mississippi River and eventually the Gulf of Mexico. The watershed supports diverse aquatic ecosystems and is an important migratory corridor for fish species. Advanced treatment at this facility helps reduce nutrient loading and protects downstream water quality.