Project Overview

National Grid is standardizing the gas main between Lowell and Tewksbury to enhance the overall safety and reliability of the existing gas distribution network through inline inspection technology, also referred to as a “Smart Pig”. The Smart Pig Technology utilizes sensors which are capable of detecting changes in pipe wall thickness and internal and external anomalies, such as third party damages or corrosion.

The use of this technology will eliminate the need to conduct ongoing excavations along the line to conduct pipeline inspections. Construction methods and schedules will vary along the route.



Project map

Project Specifications

  • Replace ~2.5 miles of existing pipe to 12” diameter between Riverneck Rd, Chelmsford to Wilbur Street, Lowell for effective Smart Pig operation
  • Utilize Horizontal Directional Drilling (HDD) under Route 495 and Lowell Connector to eliminate need for highway excavation or road closures.
  • Replace small sections of pipe in Chelmsford and Tewksbury.
  • Install Smart Pig inspection device launcher at Tewksbury Take Station.
  • Install Smart Pig inspection device receiver at Wilbur Regulator Station in Lowell.
  • Prior to start of construction, the work areas will be prepped for vegetation management needs, placement of sediment and erosion controls and/or other necessary environmental protections.
  • Existing infrastructure will be marked out by Dig Safe prior to start of excavation.

Project Schedule

Nov 2017 – Oct 2021

Stakeholder Outreach

November 2017

ENF Filing

January 2018

ENF Received

March 2018

EFSB Application Filling

Summer 2018

DEIR Filing

May 2019

FEIR Filing

June 2019

FEIR Certificate Received

Spring 2022

Construction Start

12 months

Construction Estimate