The City of Newark was looking for engineering services through design, bid and construction for the rehabilitation of an existing 24” diameter water main located in a concrete tunnel that runs south across Haynes Avenue and then east along the right of way of Haynes Avenue. Specifically, the project entailed accessing the 24” diameter water main through three (3) access vaults located along the tunnel. A portion of the water main within and directly exiting the tunnel was removed to allow installation of a cast in place pipe liner. Once the liner was installed, the section of water main that was removed was replaced with new. In order to access the water mains, portions of the existing vaults, namely the top slab had to be removed and replaced with new.
PS&S staff, while with another firm performed the design and bid phase services for this project. PS&S was awarded the contract for engineering services through the construction phase included on site construction observation.
The existing 24” water main was located in an existing below grade tunnel. Adjacent to this water main, within the same tunnel, was an existing 20” high pressure water main. Care had to be taken during construction to ensure that damage did not occur to the 20” water main. In addition, the tunnel which the water main was installed is over 100 years old. During construction it was determined that a portion of the tunnel had to be cut out and replaced in order to install the cast in place pipe liner. Lastly, in order to perform the work, the 20” water main had to be bypassed. The City of Newark’s valves were found to be non-operational during construction. In addition, the water main on Bessemer Street, which was to be bypassed, was found to feed a major Amtrak facility.
THE PS&S SOLUTION
PS&S had on site construction observation and meetings with the Contractor to stress the need to protect the existing high pressure water main. During construction, a portion of this water main was found to be leaking. PS&S worked with the Contractor to repair the leak and maintain operation of this main.