ALCOSAN slashes CSO reduction costs to $0.38 per gallon in latest $2.4m grant cycle

ALCOSAN slashes CSO reduction costs to $0.38 per gallon in latest $2.4m grant cycleBy targeting high-impact municipal source control projects, the Allegheny County Sanitary Authority has dramatically improved the cost efficiency of its Green Revitalization of Our Waterways (GROW) program. The utility's Green Committee recommended $2.4 million in new grant awards to the full board, anchored by a major sewer separation project in Etna Borough.

The Green Committee recommended $2.4 million in Cycle 12 GROW grants for eight projects across Bellevue, Etna, Wilkinsburg, and Mount Lebanon.

A strategic shift toward highly impactful projects reduced the program's cost efficiency for overflow reduction from $2.76 per gallon a year ago to just $0.38 per gallon in Cycle 12.

The cycle is anchored by the Dewey Street sewer separation project in Etna Borough, which captures regional drainage and eliminates overflows across multiple downstream CSOs.

Data from 119 completed GROW projects shows the program is vastly outperforming initial estimates, removing 1.2 billion gallons of stormwater and over 200 million gallons of overflow annually.

The Green Committee of the Allegheny County Sanitary Authority (ALCOSAN) has recommended the approval of approximately $2.4 million in grant funding for Cycle 12 of its Green Revitalization of Our Waterways (GROW) program. Advancing to the full Board of Directors for final approval at the end of March 2026, the latest funding round highlights a drastic improvement in the program's capital efficiency. During a March 17 committee meeting, staff reported that a strategic pivot initiated a year ago has successfully refocused the GROW program on highly impactful municipal source control projects. This shift has lowered the cost efficiency for combined sewer overflow (CSO) reduction from $2.76 per gallon down to just $0.38 per gallon in the current cycle. Meanwhile, the cost efficiency for stormwater removal sits at approximately six cents per gallon, with ALCOSAN's contribution accounting for about four cents per gallon. Cycle 12 comprises eight projects across four communities: Bellevue, Etna, Wilkinsburg, and Mount Lebanon. The portfolio includes seven inflow and infiltration (I&I) projects and one major sewer separation project. The cornerstone of the current cycle's overflow reduction success is the Dewey Street project in Etna Borough. Originally awarded a GROW grant in 2021, the project faced design delays that threatened associated state funding. ALCOSAN and the borough subsequently reevaluated the design, identifying structural efficiencies that significantly increased its impact. By capturing drainage from neighboring Shaler Township, the revised project will eliminate a major CSO and reduce flows across several downstream CSOs in series down to ALCOSAN's A68 diversion structure. Staff also provided an update on the historic performance of the broader GROW program. Across 119 completed projects, initial estimates projected the removal of 661 million gallons of stormwater and 147 million gallons of overflow annually. However, post-construction flow monitoring reveals the projects are vastly outperforming expectations, actively removing 1.2 billion gallons of stormwater and well over 200 million gallons of overflow per typical year. With current municipal flow monitoring programs wrapping up in June 2026, ALCOSAN anticipates a new wave of final project reports from summer through the fall as municipalities finalize consent order agreements with environmental regulators.