Key Takeaways
- The Wyoming Valley Sanitary Authority rehabilitated a major interceptor line in Wilkes-Barre using a new engineering technology, reducing the cost from an estimated $75 million to $14 million.
- The solution involved steel-reinforced PVC that interlocks as it is fed through manholes into the pipe, creating a new standalone pipe within the existing line.
- The project was completed without excavating the line, which would have compromised the flood control system along the Susquehanna River.
- The authority received funding from various sources, including the federal American Rescue Plan Act and a PENNVEST loan.
- The project highlights the importance of protecting critical infrastructure and the environment, and demonstrates the effectiveness of new technologies in reducing costs and minimizing disruptions.
Introduction to the Project
The Wyoming Valley Sanitary Authority faced a significant challenge in rehabilitating a major interceptor line in Wilkes-Barre, which is located beneath the Wyoming Valley Levee. The aging reinforced concrete line, known as the authority’s East Side Interceptor, was installed in the 1960s and had reached the end of its service life. The line carries wastewater from approximately 100,000 residents in 19 municipalities to the authority’s treatment plant in Hanover Township. Given the critical nature of this infrastructure, the authority had to find a solution that would not compromise the flood control system along the Susquehanna River.
The Traditional Approach vs. New Technology
The traditional approach to rehabilitating the interceptor line would have involved excavating to remove and replace the line, which would have cost an estimated $75 million or more. This approach would have also required extensive permitting and protective measures to ensure the flood control system was not compromised. However, the authority opted for a new engineering technology that involved steel-reinforced PVC that interlocks as it is fed through manholes into the pipe, creating a new standalone pipe within the existing line. This solution was not only more cost-effective, at $14 million, but also minimized disruptions to the surrounding area.
The Installation Process
The installation process involved feeding the steel-reinforced PVC through manholes into the pipe, using a machine to wind the large spools of PVC through the line. The diameter of the line ranges from 4 to 6 feet, allowing crews to get inside during the installation. The authority’s Chief Technical Officer, Samantha Albert, noted that the solution chosen had a significant advantage in that it did not require the interceptor line to be completely dry, as it would have with a different type of liner that requires a "curing" process with heat to dry and harden. This was critical, as the interceptor line could not be deactivated to dry due to the high volume of both wastewater and stormwater it handles.
Safety Measures and Funding
To ensure the safety of crews, the contractor set up a temporary sewage bypass system, which reduced the load passing through the line during installation. The project was funded through a combination of sources, including $2 million from Luzerne County Council’s federal American Rescue Plan Act funds, a federal STAG Clean Water Community Project Funding Grant, and a Pennsylvania Infrastructure Investment Authority (PENNVEST) loan. The authority will continue to seek grants to help fund work on other segments of the interceptor.
Partnership and Completion
The project was completed by Georgia-based Ruby-Collins Inc., which has a specialized "trenchless division" to rehabilitate underground lines. The Luzerne County Flood Protection Authority, which oversees the Wyoming Valley Levee, allowed access to land at the site to complete the project and spoke favorably of the sanitary authority’s solution. The project highlights the importance of partnerships and collaboration in completing critical infrastructure projects, and demonstrates the effectiveness of new technologies in reducing costs and minimizing disruptions.
Conclusion and Future Plans
The successful rehabilitation of the East Side Interceptor is a significant achievement for the Wyoming Valley Sanitary Authority, and demonstrates the importance of protecting critical infrastructure and the environment. The authority will continue to seek grants to help fund work on other segments of the interceptor, and will work with partners to ensure that the flood control system along the Susquehanna River remains intact. As technology continues to advance, it is likely that similar projects will become more common, reducing costs and minimizing disruptions to communities.
