ALCOSAN Eyes Eco-Improvment Projects for the Next Decade, Beyond

by Karen Price


April 5, 2022

Fixing the problem of stormwater overflow into the region’s rivers and streams that occur with snowmelt and rain will be neither cheap nor easy. But it is necessary.

The Allegheny County Sewer Authority, or ALCOSAN, has a plan to make that happen.

The agency’s Clean Water Plan is an infrastructure improvement project, the scale of which has not before been seen in Western Pennsylvania. It will include the construction of a three-tunnel system, treatment plant expansion, the agency taking ownership of multi-municipal sewers and the reduction of excess water entering the system through green initiatives.

While the plan will cost $2 billion and won’t be completed for nearly a decade and a half, the result will be seven billion fewer gallons of stormwater entering the waterways every year.

“First and foremost, the Clean Water Plan’s importance is to our rivers and streams, as the end result will be fewer overflows and thereby cleaner rivers,” said ALCOSAN director of communications Joseph Vallarian. “This leads to a myriad of positives for the region — increased recreation, increased riverfront development, better water for intakes at water treatment plants. Obviously, these projects — especially the plant expansion and the regional tunnel system — are infrastructure. ALCOSAN is building infrastructure, obviously a hot topic lately.”  

Right now, about nine billion gallons of diluted, untreated wastewater enter our rivers each year from combined and sanitary sewers. Expanding ALCOSAN’s capacity to treat wastewater at its North Shore plant will help, but that’s only part of the solution. 

The Clean Water Plan also calls for the Green Revitalization of our Waterways (or GROW) plan, which includes diverting streams from entering sewers, lining and repairing pipes and using green infrastructure. It also involves working with partner municipalities to take ownership of over 200 miles of multi-municipal lines to make the system more efficient. 

Finally, the biggest component of the plan will be the construction of 16.5 miles of tunnels underneath existing infrastructure along all three rivers. 

The current system and infrastructure was built in the 1950s. ALCOSAN must work to reduce overflow into the rivers by federal decree, and failure to do so will result in fines. 

ALCOSAN is currently taking public comment on the plan. Construction could begin as early as 2025 beginning with the tunnel under the Ohio River with completion of the initial goals of the plan coming in 2036. 

The Clean Water Plan will also bring business and educational opportunities to the region.

“It is estimated (by the Pennsylvania Economy League of Greater Pittsburgh) that the tunnel projects alone will support nearly 14,000 direct jobs, 2,149 indirect jobs, and $2.6 billion in total economic output contributed to Allegheny County’s economy,” Vallarian said. “On a broader level, there are a lot of local companies working on these projects – especially the plant expansion and the coming regional tunnel system.”