A $4.5 billion clean-water fix is about to go underground

Work is expected to begin this summer on a centerpiece of what could become one of the largest public works projects in recent Allegheny County history.

ALCOSAN’s board recently approved a $1.1 billion bid to build a 4.9-mile Ohio River Tunnel, the first of three underground channels designed to capture sewage-laced stormwater before it reaches the Ohio, Allegheny, and Monongahela rivers, and other waterways.

Pittsburgh is one of several cities around the country grappling with aging systems built to carry stormwater and sewage through the same pipes.

Once complete, “the rivers and the streams that the tunnels are supporting will be much, much cleaner,” said Jonathan Burgess, director of the Pittsburgh Water Collaboratory at the University of Pittsburgh.

Right now, even a tenth of an inch of rain can overload the system, sending untreated stormwater and sewage into the rivers in what is known as a “combined sewer overflow.”

Under federal pressure to comply with the 1972 Clean Water Act, communities from Washington, D.C., to Columbus, Ohio, have spent billions of dollars digging tunnels and overhauling aging systems to keep raw sewage out of waterways.  

In Allegheny County, that mandate now carries a multibillion-dollar price tag — and the promise of cleaner rivers that could reshape aquatic ecosystems, as well as how residents use and experience the region’s waterfronts.

“This truly has been a long time coming,” Arletta Scott Williams, executive director of ALCOSAN, said at the board meeting where the contract for the first tunnel was approved.    

Altogether, the three tunnels are the centerpiece of ALCOSAN’s Clean Water Plan, also known as the Wet Weather Plan, which was developed to meet requirements under the Clean Water Act.

The entire Clean Water Plan is projected to cost more than $4.5 billion, up from $2.2 billion in 2022.  

Kimberly Kennedy, director of engineering and construction, said the $2 billion figure is from 2010 and is outdated. “Costs for everything have gone up,” she said.

The Clean Water Plan will be “primarily funded through rates,” said Jill Snyder, director of communications.  

In 2018, ALCOSAN increased rates by 7.5% to pay for the Clean Water Plan.

Since 2019, rates have increased by 7% annually under a measure set to expire this year. But the sewer authority anticipates that annual increases will continue to be necessary, Kennedy said.

Once the plan is implemented, there will be more spots along the river open to recreation, Burgess said. “Ideally, those places will be not just clean and healthy to engage with, but offer recreational access and opportunities for us to get on the water.”

Under a 2020 modification to a 2008 consent decree, ALCOSAN committed to reducing sewer overflows into regional waterways by an estimated 6.6 billion gallons annually by 2036, according to the EPA. A consent decree is a legally binding, court-approved agreement — in this case, between ALCOSAN and the EPA. The Clean Water Plan was created to meet the requirements of that agreement.

The first major construction contract for the tunnels was awarded to Brayman Construction Corporation and The Lane Construction Corporation. Lane is a U.S. subsidiary of Webuild Group, based in Milan, Italy. Brayman’s chairman and CEO, Stephen Muck, is based in Butler County.  

The companies, together known as Steel City Tunnel Partners, submitted the lowest of three bids; the other two topped $1.2 billion.  

ALCOSAN expects to give Steel City Tunnel Partners notice to proceed in June, which “starts their clock,” Kennedy said. Under the contract, the companies must complete the project within six years and five months following the notice.

Of the $1.1 billion contract, $52 million is an earmarked “contingency,” meaning it will not be spent automatically, only with authorization, Kennedy said.

ALCOSAN has already spent around $45 million on the Ohio River Tunnel, including design, salaries for the construction management team, and preparatory construction, according to Kennedy. Including additional planning, property acquisition, and overall program management costs, total spending so far is about $80 million.

Kennedy expects the Allegheny River Tunnel to begin construction in 2029 and be completed by 2035, according to the implementation timeline on the ALCOSAN website. A final tunnel, the Monongahela River Tunnel, is projected to begin construction in late 2030 and be completed by 2037.

But timelines for the entire three-tunnel project could shift based on data gathered during the construction of the Ohio River Tunnel.

“Once we have that data, then we’ll be able to say, ‘OK, based on that — does this timeframe make sense for the next two tunnels,’” Kennedy said. “Based on real data from Pittsburgh geology, in this condition.”

HEADER IMAGE:  Work could begin this summer on multiyear project by ALCOSAN to protect the rivers against sewage overflows. Erin Yudt/Pittsburgh Media Partnership Newsroom

Hannah Frances Johansson is a reporter for the Pittsburgh Media Partnership Newsroom. She holds a master's degree from the UC Berkeley Graduate School of Journalism. Reach her at hannah.johansson@pointpark.edu.

‍The PMP Newsroom is a regional news service that focuses on government and enterprise reporting in southwestern Pennsylvania. Find out more information on foundation and corporate funders here.