Sewer Regionalization and ALCOSAN Wet Weather Plan

ALCOSAN's wastewater treatment plant in Woods Run, Pa.

PEC worked with other local civic and environmental organizations to address the region’s stormwater management problem. Additionally, we submitted recommendations to make ALCOSAN’s Wet Weather Plan more effective.


The Allegheny County  Sanitary Authority (ALCOSAN) owns and operates 90 miles of interceptor lines and a 250 million gallon per day wastewater treatment plant, which receives sewage and stormwater from 83 local municipalities. But like so many other urban areas, Allegheny County’s wastewater treatment system is aging and outdated, leaving the region with a serious combined sewer overflow (CSO) and sanitary sewer overflow (SSO) problem.

In 2008, the U.S. Environmental Protection Agency (EPA) entered into a consent decree with ALCOSAN, aimed at developing a wet weather plan for reducing CSO’s into the area’s watersheds. Meanwhile, the Pennsylvania Department of Environmental Protection (DEP) signed consent orders with all 83 of ALCOSAN’s municipal customers, requiring each to complete feasibility studies for controlling their CSO’s.

But with no regional strategy for coordinating sewage collection and treatment, compliance with the Clean Water Act would be improbable. At ALCOSAN’s request, the Allegheny Conference on Community Development convened a review panel to address regionalization of the ALCOSAN system and make recommendations. The 34-member panel, which included PEC, developed alternatives for regionalizing ALCOSAN’s decentralized system in order to help improve the area’s water quality.

Simultaneously, ALCOSAN released its Wet Weather Plan that called for one of the largest public works initiatives in the region’s history to  improve water quality for the region’s watersheds and implement solutions to regulatory compliance. As part of the public process, PEC submitted recommendations to ALCOSAN to promote greater use of green infrastructure, regional coordination, and source reduction throughout the system.

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