Mini-System 35 Sewer Rehabilitation Project

The Mini-System #35 Sewer Rehabilitation Project is a sanitary sewer rehabilitation project focused on preventing groundwater infiltration into the sanitary sewer.

Project Goal

The goal of this Project is to make the sanitary sewer watertight. Princeton currently pays to treat more wastewater than residents and businesses actually produce. By reducing the amount of clean groundwater that enters the sanitary sewer system, Princeton will be able to reduce the costs associated with wastewater treatment. Additionally, the process used to seal the pipes will extend their useful life, forestalling more invasive infrastructure replacement projects and disturbances to private property.

Scope of Work

The Project involves repair work on both the public sewer pipes (mains) and the private sewer pipes serving each property (laterals) in the Project area. The Project primarily involves injecting a non-toxic chemical grout into the joints and cracks of sanitary sewer pipes, to eliminate groundwater leaking into the sanitary sewer system. Chemical grouting is a trenchless technology which does not require any digging. 

Please Note: The scope of work was modified in response to bids received under the original scope. Some areas were removed from the project resulting in fewer sections of sewer to be rehabilitated. The Mini-System #35 Updated Project Area Map indicated the sections of sewer which will be rehabilitated during this work. The pipes that were removed from the project will be rehabilitated under a separate future project.


National Water Main Cleaning Company, of Kearny New Jersey, will be the contractor for this project. 

Right of Entry Agreements

In order to complete the Project, Princeton will need temporary access to the portions of the public sanitary sewer system located on private property. Right of Entry Agreements were mailed to affected residents on February 11, 2022. 

Project Notifications

Visit the Notify Me page to sign up for project notifications. Engineering - Mini-System #35 Sewer Rehabilitation Project is listed in the News Flash category. You may need to scroll down to see this list. Click the icons on the left to sign up for email and/or text notifications. You must register on the website to receive notifications. 

Community Meeting

A community Zoom meeting is scheduled for February 23, 2022 at 6:00 p.m. to answer any questions regarding the Project and the Right of Entry Agreements. Please go to the Mini-System #35 Sewer Rehabilitation Project Virtual Community Meeting event on the Calendar to register for and join the meeting.

Relevant Documents

Mini-System #35 Updated Project Area Map

Mini-System 35 Updated Project Area Map
  1. Engineering Department

    Physical Address
    400 Witherspoon Street
    Princeton, NJ 08540

    Fax: 609-688-2026

  2. Andrew Filippi

    Sewer Engineer