Savvy engineering keeps Etna’s storm water from traveling to ALCOSAN and lightens the burden on the region’s aging sewer system.
On the quiet block of Butler Street bounded by Bridge and Freeport in Etna, there are few signs to indicate a massive infrastructure project is underway. Only twelve new trees and a meandering iron grate hint at what’s underfoot.
Beneath the pavement rests a new system of pipes and tanks capable of catching and slowly releasing over 1,600 cubic feet of storm water. A $415,500 grant from the Environmental Protection Agency allowed Etna to complete this first stage of a multi-phase overhaul intended to divert storm water into the ground instead of flowing into the regional sewer system, operated by the Allegheny County Sanitary Authority (ALCOSAN).
Etna, like many communities along the rivers, has a history of flooding. When it pours, storm water can overwhelm the aging system and send untreated water flowing into rivers and streams. Green infrastructure like Etna’s can prevent storm water from ever reaching ALCOSAN, which reduces the burden on the treatment plant as well as the likelihood of sewage overflow.
Estimates suggest that over 35 years, Etna’s green infrastructure master plan will save $5.5 million to both ALCOSAN and the borough by annually diverting 16.1 million gallons.
“It just makes sense – an ounce of prevention is still worth a pound of cure,” says Executive Director of ALCOSAN, Arletta Scott Williams. “Everything we do to keep storm water out of our sewers helps, and the benefits of having a more beautiful and inviting community – and lower costs – through green design is the icing on the cake.”
Another less visible benefit says system designer and borough engineer, Don Newman, is that those millions of gallons of diverted water will recharge local groundwater systems.
Availability of future funding will determine the pace of revamping Etna’s storm water management. But a small parking lot wedged between Walnut and School Streets demonstrates that even small infrastructure advances can have a big impact. With space for just nine cars—ten if you count the one reserved for the pastor of the First Congregational Church—the lot was rebuilt to manage water runoff for an area ten times its size. It’s capable of processing 540,000 gallons.
Newman sees Etna as proof of concept for green infrastructure.
“What we’re really excited about is demonstrating how you can do this. It shows that in very well-developed, densely packed commercial centers you can make this stuff work.”
Now that the construction equipment is gone, Etna doesn’t look much different. For many, like the boy using the smooth new parking lot as a bike shortcut, the infrastructure changes will succeed not by being obvious, but by making the borough more livable.
Stefanik’s Next Generation Contracting built the new system. Don Newman is an engineer with Buchart Horn, Inc.