Historic Civil War Era 48-in. Outfall Sewers Fully Renewed Using CIPP Technology in Hoboken, NJ: Fid-Bau Portal

Historic Civil War Era 48-in. Outfall Sewers Fully Renewed Using CIPP Technology in Hoboken, NJ

Wade, Mark / Pocci, Fredric / Tobia, John / Camali, Gene

The North Hudson Sewerage Authority owns and maintains a combined sewer system including twin 48-in. outfall sewers that date back to the Civil War. In general, both outfalls are tidally influenced and completely inaccessible. Both outfalls had fallen into such a state of disrepair that traditional and state-of-the-art mechanical and hydraulic pipeline cleaning tools could not even be used to investigate and assess their condition. Specifically, impenetrable amounts of hard sediment, calcification, and tuberculation had choked these grey iron pipelines to such an extent that the only viable solution was direct hand-mining of these calcified pipes with pneumatic chipping hammers to reopen and restore their full diameter. Further complicating the rehabilitation were the deflections, large cavities, transitions, and curves in the outfalls as they crossed below a very large and active rail yard. A cured-in-place pipe liner was ultimately chosen from a wide range of technology options to structurally reline the outfalls. Rehabilitation of each outfall also had to take place while keeping at least one in service beneath 18 active and parallel New Jersey Transit Rail tracks at the Hoboken Terminal. The greatest value for the Authority in terms of long-term infrastructure improvements and incorporating sustainable design was the extended service life combined with significant increase in conveyance capacity to prevent future wet-weather flooding of the combined sewer system. The use of CIPP trenchless solutions provided a cost-efficient alternative to a nearly impossible replacement or relocation strategy that would have required major disruptions to the City of Hoboken, the New Jersey Transit, and other critical transportation infrastructure. Ultimately, the project was completed with virtually no disruption to these critical assets.