Pittsburgh Begins $2 Billion Sewer System Overhaul

May 21, 2018

The $2 billion sewer system upgrade in Pittsburgh has a new engineering firm who will oversee the expansion of the city's waste water treatment plant and get the overhaul of the entire system flowing.

The Pittsburgh Post-Gazette reports that every flush in Pittsburgh and 82 nearby municipalities is supposed to end up at Alcosan's plant along the Ohio River, but the complex of pumps and tanks is overwhelmed when rain pours into the sewers.

Last week the Allegheny County Sanitary Authority's board of directors voted to hire Michael Baker International to oversee the $300 million-plus Alcosan plant expansion that is part of an overall sewer system upgrade that will last until 2027 and cost at least $2 billion.

Like many aging cities, Pittsburgh's sewer system has antiquated lines, some up to 100 years old and made of brick.  When the city's population began to grow in the early 1900's, the waste water network lacked preemptive planning. After heavy rainfall, the system network is overwhelmed and according to a 2004 EPA study, 16 billion gallons of raw sewage gets dumped into area rivers. The Allegheny County Sanitary Authority manages SOAK, a sewer advisory website for residents to check on the area's overflow status.

Alcosan plans to double the plant's capacity for treating wastewater and stormwater. Michael Baker will be paid an estimated $30 million to enforce the project's schedule, keep costs under control, and meet regulations. The plant expansion is expected to reduce by 3 billion gallons the amount of wastewater that flows, untreated, into Pittsburg-area rivers and streams each year.

A view of the final effluent discharge of purified water going into the Ohio River on Monday at the Alcosan plant.(Steph Chambers/Post-Gazette)

The massive job will be broken into phases with construction likely to start in 2020.

Read more about the challenges the project will present, including creating a 'grey infrastructure'  in the Pittsburgh Post-Gazette story Massive, $2 Billion Overhaul Of Area's Sewer System Revs Up With $30 Million Contract.