3 Rivers Wet Weather was created specifically to help 83 Allegheny County municipalities, including the City of Pittsburgh, develop a long-term, regional solution to the wet weather problem. The sewage collection systems, consisting of nearly 4,000 miles of pipes, in these communities flow into one wastewater treatment plant—the Allegheny County Sanitary Authority (ALCOSAN).
The municipal collection systems in the following communities transport sewage to the Allegheny County Sanitary Authority (ALCOSAN) treatment facility located on Preble Avenue in the Woods Run area of Pittsburgh. If a community has a municipal authority, it is also listed below.
Girty's Run Joint Sewer Authority
McCandless Township Sanitary Authority
North Versailles Township Municipal Authority
Ohio Township Sanitary Authority
Penn Township Sewage Authority
Peters Township Sanitary Authority
Plum Borough Municipal Authority
The Municipal Authority of the Township of Robinson
Municipal Authority Township of South Fayette
West Mifflin Sanitary Sewer Municipal Authority
Wilkinsburg-Penn Joint Water Authority