PRINCETON MINI SYSTEM #36 SANITARY SEWER REHAB

The Municipality of Princeton recently closed on a $6.3 million loan with the New Jersey Water Bank to rehabilitate its Mini System #36 and #36A. These wastewater collection subsystems include a mix of lined and unlined 8- to 15-inch sewer pipes, along with their associated tap connections, maintenance holes, and lateral lines tied into those structures.

This project focuses on reducing infiltration and inflow (I&I), the excess groundwater and stormwater that enter the sanitary system and strain treatment capacity. To accomplish this, Princeton will use a combination of comprehensive TV inspection and capital grouting techniques to identify and seal leaks throughout the system.

Capital grouting is a trenchless rehabilitation method used to stop I&I without replacing entire pipe segments. After the system is televised and leak points are mapped, crews inject specialized grout materials through the pipe wall, joints, or service connections. The grout fills voids surrounding the pipe, seals cracks and defective joints, and stabilizes the soil around the infrastructure. Once cured, the grout forms a watertight barrier that prevents groundwater from entering and helps restore the structural integrity of aging assets.

This approach is cost-effective, minimally disruptive, and extends the useful life of existing infrastructure. By investing in targeted I&I control, Princeton is taking a proactive step to protect wastewater treatment capacity, reduce operating costs, and improve long-term system reliability.