Originally installed in 1914, our crews are currently rehabilitating a water main that runs beneath the river by installing a carbon fiber lining inside the pipe. Carbon fiber water main lining is used because it provides a fast, strong, and minimally disruptive way to rehabilitate aging or damaged pipes, especially large diameter transmission mains, like the one we’re working on for this project.
This upgrade is essential to maintain long‑term reliability.
The pipe is a 48" riveted steel main that dates from 1914 and is over 1,000 feet long!
Project Schedule & Work Hours:
| Status | In Progress |
| Start Date | 9/1/2025 |
| End Date | Mid-Summer 2026 |
Work Hours: Equipment must stay operational overnight due to the need to keep the pipe dewatered.
About the Work:
To perform the work safely, crews must enter the pipe, which runs along the river bottom at 26th street over to the North Shore. To access this large, underwater pipe, we must dewater it. Our equipment must continuously run to maintain a safe and functional work environment.
We understand the equipment creates noise, and this is difficult, especially during overnight hours. Our teams are doing what they can to reduce noise in the evenings wherever possible. Construction is expected to continue through mid‑summer.
Why are we doing carbon fiber lining?
Carbon fiber reinforced polymer (CFRP) systems are corrosion‑resistant and highly durable. Once installed, it slows deterioration and give utilities a long-term solution without the cost and complexity of full pipe replacement, extending the service life by 50+ years.
This work restores structural strength without full replacement. Carbon fiber composites are extremely strong and lightweight. When applied inside a pipe, it creates a new structural “pipe within a pipe,” allowing old water mains to regain or exceed its original pressure rating.
Carbon fiber relining also minimizes the need to excavate roads. Instead of digging up long sections of roadway, crews access the pipe through small pits or existing manholes. This means:
- Fewer traffic disruptions and road closures
- Shorter construction timelines
- Less street restoration work
- Lower impact on residents and businesses
This is an immense benefit in dense urban areas like Pittsburgh.