Allegheny County Sanitary Authority
Allegheny County Sanitary Authority (also known as ALCOSAN) is a municipal authority in Allegheny County, Pennsylvania that provides wastewater treatment services to 83 communities, including the city of Pittsburgh. Its principal sewage treatment plant is along the Ohio River downstream from Pittsburgh (see satellite photo).
Source: Wikipedia — Allegheny County Sanitary Authority (CC BY-SA 4.0)