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Eroded Streambank Wall Gets an Extreme Makeover

Retaining wall edition.

Published Oct. 30, 2020
The U.S. Army Corps of Engineers Pittsburgh District, in partnership with Pleasant Hills Authority, hosted a ribbon-cutting ceremony on Oct. 21 to signify the completion of the Streambank Protection Project.

The U.S. Army Corps of Engineers Pittsburgh District, in partnership with Pleasant Hills Authority, hosted a ribbon-cutting ceremony on Oct. 21 to signify the completion of the Streambank Protection Project.

The U.S. Army Corps of Engineers Pittsburgh District, in partnership with Pleasant Hills Authority, hosted a ribbon-cutting ceremony on Oct. 21 to signify the completion of the Streambank Protection Project.

The U.S. Army Corps of Engineers Pittsburgh District, in partnership with Pleasant Hills Authority, hosted a ribbon-cutting ceremony on Oct. 21 to signify the completion of the Streambank Protection Project.

The U.S. Army Corps of Engineers Pittsburgh District, in partnership with Pleasant Hills Authority, hosted a ribbon-cutting ceremony on Oct. 21 to signify the completion of the Streambank Protection Project.

The U.S. Army Corps of Engineers Pittsburgh District, in partnership with Pleasant Hills Authority, hosted a ribbon-cutting ceremony on Oct. 21 to signify the completion of the Streambank Protection Project.

Approximately 20 people gathered near what appeared to be an insignificant wall to celebrate the completion of a project that has an enormous impact on six communities.

The U.S. Army Corps of Engineers Pittsburgh District, in partnership with Pleasant Hills Authority, hosted a ribbon-cutting ceremony in front of the newly completed retaining wall along the Lick Run streambank in Jefferson Hills, Pennsylvania, Oct. 21.

If you ever drove down Cochran Mill Road in Jefferson Hills, you unknowingly passed Lick Run Stream. Driving pass, you probably would not noticed the erosion at bottom of the steep bank. You also would not have seen that erosion was also slowly compromising the sewage treatment facility infrastructure located just along these banks – a facility that handles an average of 3-million gallons of sewage per day for 8,300 Allegheny County residents living in Pleasant Hills, Baldwin, South Park, Whitehall, Bethel Park, and Jefferson townships.

The consequences of the Pleasant Hills Authority Wastewater Treatment Plant failing prompted the $1.3-million restoration project. It repaired 1,700 feet of streambank, delivering a permanent solution to this ongoing issue.

"These are the types of projects we love to do because they provide direct value to our community. And there is something special that happens when you can provide a true public service," said Lt. Col. Albert Butler, deputy commander, Pittsburgh District, during his opening remarks.

In attendance was Chairman of Pleasant Hills Authority, Richard "Dick" Nieman. He said the original flow of Lick Run Stream was redirected to accommodate adequate space for the facilities. However, this action turned out to be a temporary solution. Nieman explained how a major hurricane in the 1970s caused the stream to revert to its original course. Over time, the erosion worsened and jeopardized the facility's aeration tanks, influent pipeline, storage tanks, and other infrastructure.

"We have been fighting a battle ever since," said Nieman. "It was suggested we go look for the people who are experts at this kind of thing, the U.S. Army Corps of Engineers."

Under Section 14 of the Flood Control Act of 1946, the corps is given authorization to partner with a non-federal sponsor to plan and construct emergency streambank and shoreline protection for public facilities in danger of failing due to natural erosion.

Andrea Carson, who worked closely with the stakeholders on the project, explains the importance.

"Through our different authorities, we can assist communities such as this one. It allows the corps to partner, cost-share projects, help study the issue and find a solution," said Carson.

The district's Planning and Environmental Branch's goal is to form partnerships with local communities to resolve water resource management issues. The team completed the feasibility study using a cost-share agreement of 65 percent Pittsburgh District and 35 percent PHA split. Carson added, "In the case of this project at Lick Run, we can take that study into design and implementation, which is why we are here today."

Construction began on March 17 with a five-person crew from Aspen Construction Company. They installed the retaining wall using a combination of riprap and precast concrete-modular block with adequate draining using construction fabric and gravel.

Lt. Col. Butler said, "This was a very real problem in our community that we were able to be actively engaged in."

The Lick Run Streambank Protection Project was completed in less than a year from when the contract was awarded on September 27, 2019 to the completion of construction on June 26, 2020. The derived solution resolves erosion issues, permitting the PHA Wastewater Treatment Plant to continue to serve its communities for decades to come.