A construction restoration project is underway in the greater Lawrence area of Massachusetts as Columbia Gas of Massachusetts aims to restart natural gas service to customers by mid-November.

The plan includes installing gas main lines and service lines, as well as installing and testing gas meters that measure and regulate gas flow to homes and businesses.

An independent evaluator is being brought in by Massachusetts regulators to examine the safety of the state’s entire natural gas distribution system following a series of fatal explosions and fires on Sept. 13 in the Merrimack Valley linked to the Columbia Gas system.

Emergency responders converged in Lawrence, Andover and North Andover after gas explosions and fires killed one man, injured about 25 people and destroyed or damaged dozens of homes. The National Transportation Safety Board is investigating, and Columbia Gas said it would undertake the replacement program.

The utility is deploying nearly 200 construction crews as part of a combined workforce of about 3,000 employees and contractors. The project has a tentative completion date of Nov. 19, “with progressive restoration of customers’ gas service,” the utility said.

“We’ve been working with partners at every level of government, with our first responders and departments of public works in our planning efforts to rebuild the system,” said the utility’s chief recovery officer Joe Albanese. “Our early actions, supported by the National Guard, helped meet some immediate community needs. Now we turn to our current effort in support of the primary mission – to restore gas service to homes and businesses.”

NiSource’s chief restoration officer Pablo Vegas said, “As we continue to support those in need, we are now unveiling our planned path to restoring service, and will be sharing our plans and progress as we move forward. We know it takes actions, not just words, to show our commitment.”

Columbia Gas has identified eight work zones, defined into 63 projects, that would run in parallel across the three communities to organize and plan restoration efforts.

The utility outlined three main areas of work to be done. The first is to make homes/businesses “gas ready,” with construction crews installing the main gas lines. The gas ready current scope of work includes installing about 45 miles of pipeline and 6,100 service lines.

The second major initiative is to make home/businesses “house ready,” by assessing gas appliances and piping, as well as testing gas lines. The third is to relight systems once the structures are gas and house ready. A Columbia Gas representative plans to visit each home or business to perform additional safety checks and restore gas service.