The completion of a $4.7 million sewage outfall is just another piece of a long period of investment needed in the Pittsburgh region’s sewage infrastructure, according to local leaders who celebrated the completion of the project Monday.
Both the Pittsburgh Water and Sewer Authority and the Allegheny County Sanitary Authority are in the process of investing hundreds of millions of dollars per year in the region’s drinking water and sewage infrastructure. Right now, one of the biggest problems is that on rainy days, both sewage and stormwater end up in the same pipes. And to prevent the system from being overwhelmed, millions of gallons of this combination are diverted into the rivers. There are around 100 outfalls where this raw sewage pours into the rivers.
On Monday, leaders from PWSA and ALCOSAN celebrated the rehabilitation of one of those outfalls near Hazelwood Green. The outfall carries about 400 million gallons of raw sewage and stormwater, one of the biggest in the system. The flow comes from upstream neighborhoods like Oakland, Squirrel Hill, Hazelwood and the Run. But the outfall was over 100 years old, and its failure would be a problem for those neighborhoods, said Kate Mechler, PWSA’s deputy director of engineering.
PWSA and ALCOSAN leaders say now that the project is complete, there should be even fewer basement backups in those neighborhoods. Although Will Pickering, the CEO of PWSA, didn’t know exactly how many homes would be affected, he said the project was part of a larger effort to address flooding and basement backups upstream.
PWSA reinforced the pipe with rebar and applied a liner. And as part of the project, a new “flap gate” was added. The gate will prevent river water from flowing into the sewer system when it’s not raining. ALCOSAN says this will prevent about 60 million gallons of river water and sediment from creeping back into the system. The project also lowered a portion of the sewage system upstream, allowing the sewage overflows to move more quickly down to the river and making it less likely for basement backups to occur.
Over the next couple of decades, outfalls like this will see fewer sewage overflows as ALCOSAN begins to build out its multibillion-dollar Wet Weather Plan. This plan includes increasing the size of the existing sewage treatment plant and building around 15 miles of underground tunnels to capture excess stormwater and sewage.
The flap gate in the new outfall will still be useful in the upgraded system, as it prevents river water from entering, according to ALCOSAN.
Pittsburgh deputy mayor Jake Pawlak says that while many areas of the country are seeing droughts, Pittsburgh is seeing more rainfall from climate change. In the long run, he says, the region’s ample water supply will be a boon for the area, but only if we invest in it now.
“Clean drinking water, water for our health, our economy and industry is the competitive advantage of our region over the next century. It's our most precious natural resource,” he said. “And so investments in preserving the quality of that water and in preventing further water quality impairments in counteracting our history of pollution are vital.”
Pawlak said there had been a history of mismanagement and underinvestment. So PWSA and ALCOSAN need to do these projects now, even though they are expensive. Pawlak pointed to PWSA and ALCOSAN’s programs to help low-income residents pay their bills as key to ensuring these costs are “equitably dispersed across the rate-paying public.”
