Overview

Project Completion - the project was substantially completed in December of 2025, and the final punch list activities will occur in the Spring of 2026.

This project will help the Town of Nantucket to upgrade its current sewer forcemain infrastructure by installing a third pipe that will eventually allow the Town to retire its old 16-inch pipe that experienced a catastrophic failure during the winter of 2018, and perform an internal assessment of its exiting 20-inch ductile iron pipe that has been in operation since 1986. The assessment of the 20-inch ductile iron pipe will determine the course of action for the pipe rehabilitation. Once complete, the Town will have 2 reliable sewer forcemains that provide a much-needed system redundancy and reduce the risk of any future failures of the sewer system. In addition to installing a new sewer forcemain, the Town is taking advantage of replacing aged infrastructure along the forcemain alignment by replacing aged water mains, gravity sewers, and drainage upgrades where feasible. Once the new pipeline installation is completed, restoration work will begin along the alignment.

Per approval of the force main route by the Select Board, the project will include the installation of a new sewer force main that connects the Sea Street Pump Station (SSPS) to the Surfside Wastewater Treatment Facility (WWTF). The project will also include upgrades to water, sewer, and drain utilities along the Town-approved sewer force main route:

• APPROXIMATE LENGTH OF PROPOSED SEWER FORCE MAIN: 18,140 LF
• APPROXIMATE LENGTH OF PROPOSED WATER MAIN REPLACEMENT: 5,360 LF
• APPROXIMATE LENGTH IF PROPOSED GRAVITY SEWER REPLACEMENT: 4,900 LF
• APPROXIMATE LENGTH OF PROPOSED STORM DRAIN REPLACEMENT: 445 LF

Needs Assessment

Two sewer force mains currently connect the SSPS and the WWTF: a 20-inch force main installed in 1981, and a 16-inch force main installed in the 1930s and later rehabilitated in 1983-1984. These two force mains carry up to 3 million gallons per day of wastewater and account for approximately 70% of the collected sewage to the WWTF. Following the catastrophic failure of the 16-inch force main during the Winter of 2018, the Town conducted a study on the pipe to confirm its condition. The study concluded that due to the age and condition of the 16-inch force main, it should no longer be relied upon to convey wastewater flows from the SSPS to the WWTF without an additional backup pipe. As a result of the assessment, the Town has proceeded with the design and construction of a third force main from the SSPS to the WWTF. Once completed, the Town will be able to rehabilitate the existing aging 20-inch force main and retire the existing 16-inch force main.

Project Areas

Town streets where construction of the force main and associated utilities will be installed include:

• Sea Street
• Step Lane
• Centre Street
• Lily Street
• Liberty Street
• Winter Street
• Pine Street
• Silver Street
• Pleasant Street
• Atlantic Avenue
• Surfside Road
• S. Shore Road

A section of this force main falls within the historic downtown area. As such, brick sidewalks and curbing affected by construction will restored in accordance with the Town of Nantucket HDC standards as required by the project’s contract documents. All construction will occur within the existing Town-owned right-of-way.

As a part of the Sea Street Pump Station Sewer Force Main No. 3 (SSPSFM3) project, vibration monitors have been installed in town. These electronic devices look like small black suitcases (or Pelican boxes) and have placed along Step Lane and along the rest of the project route (including Sea Street, Center Street, Lily Street, Liberty Street, Winter Street, and Pine Street). These devices will help monitor vibrations during construction, as well as the other geotechnical instruments already installed along the route. If you have any questions on this or any aspects of the SSPSFM3 project, please reach out to the Nantucket Sewer Department.

Project Coordinators

• Town of Nantucket – Town Administration & Sewer Department
• Owner’s Project Representative – Hazen and Sawyer
• Design Engineer – Environmental Partners Group, LLC.
• Construction Contractor – Robert B. Our

Weekly Construction Hours

• Monday – Friday 7:30 AM – 5 PM

Road Closures

Road closures related to this project will no longer be posted on this page. They will now be included in our weekly update on our dedicated Road Closures page. Please visit the page and subscribe to receive updates directly to your inbox.