Overview

The Capacity Management Operations and Maintenance (CMOM) Program for the sewer system completed the first round of the Island-wide infrastructure assessment in 2021. Pipe and manhole defects were inventoried and prioritized. A recent construction project repaired the higher priority defects using a combined method of Excavated Point Repairs (i.e. replacing only a small segment of damaged pipe), and Trenchless Pipe Lining (described below). This project repaired 95 segments of damaged pipe throughout Sconset and Town and was completed in 2022.

Methods

Trenchless Pipe Lining
Two methods of pipe lining have been used on Nantucket to repair cracks and holes in pipe walls: Cured-in-Place Pipe (CIPP) and Interior Spot Repairs (ISRs). CIPP is a method that lines the entire length of the pipe using a fabric tube that is placed in the pipe using the manhole, and the resein within the liner is cured with steam for 2-3 hours to create a hard, dry structural pipe within the existing pipe. The ISR method patches 5-10 feet of the pipe using a different resin, which cures in 2 hours at ambient temperature without the need for steam. This option is ideal if the pipe segment only had one isolated defect. Using these methods, two, sometimes three pipe segments (500-800 feet) could be lined in a single day all without having to excavate in the street or pave afterwards.

Open Cut Trenching
In the cases where existing piping is determined to be undersized or in a state of deterioration that is ineligible for the CIPP or ISR methods, traditional open cut trenching is required. During excavation, the sewer pipe is replaced in its entirety until it may connect with viable existing pipe. Other utilities (e.g. water mains, storm drains) may be repaired or replaced while the trench is open, which is coordinated with the respective utility entities before the start of the project, and in certain cases during the work if something is discovered to be in disrepair.

Current Focus

Continuing to address the more severe defects, a second construction project has been initiated that will replace entire lengths of sewer pipe that were determined to be deteriorated and undersized. The buried Utility Improvements on Vestal Street, East Dover Street, Pleasant Street (Cherry Street to New Street), King Street, Shell Street and Center Sias Street were completed by February 2025. Final surfacing for East Dover and King Street were completed in the fall of 2024. Forthcoming final surfacing for Vestal Street, Pleasant Street, Shell Street and Center Street) is expected to occur in the spring and fall of 2025.

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.