Group looks to unearth streams buried century ago
PITTSBURGH (AP) – An environmental research group at Carnegie Mellon University has suggested unearthing streams, some buried for more than a century, as part of a massive sewer upgrade project in Allegheny County. The 3 Rivers-2nd Nature group, funded by a grant from the Heinz Endowment, said more than half of Allegheny County’s 23 buried streams could be “daylighted.”
In the late 1800s, combined sewers were installed that would carry storm water and human waste through the same channels, effectively syphoning natural streams.
Other streams were buried in an effort to create flat land for industrial or housing projects. Hillsides were cut away to fill in valleys and their rivers.
A study by 2nd Nature suggests at least 12 of the streams would be good candidates to be unearthed. The project would return the natural surface flow to streams, some with names that have long been forgotten.
The subsurface streams add nearly 2 million gallons of water daily to the 190 million gallons that flow through the county’s North Side treatment plant.
That volume can double during a storm.
One such stream recovery project is currently underway.
The city and the Army Corps of Engineers are spending $7.7 million to relocate and repair sewer lines that feed the city’s only free-flowing stream for the last 90 years.
Nine Mile Run, though it is not buried, periodically disappears into broken sewer mains.
“It’s an important kind of project,” said John Schombert, executive director of 3 Rivers Wet Weather Demonstration Project. “It will create a warm water fishery in an urban setting.”
The project will restore natural features to the stream that flows through Frick Park and improve the wildlife habitat around it.
The Justice Department and Environmental Protection Agency in 1996 ordered 50 of 83 communities and the authority that controls county sewers – known as Alcosan – to clean up sewage problems or face fines. The upgrades are expected to cost approximately $2 billion.
“People ought to be able to get something back, more than sewers, from spending all this money.”
The study said not every stream should be uncovered, but recommended one of the first could be a long-buried stream that would flow into Chartiers Creek.
That stream has the potential to create sizable wetlands that would serve as a habitat for fish in Chartiers Creek and other aquatic life.