Massachusetts regulators plan to hire an independent evaluator to examine the safety of the state’s natural gas distribution system following a series of fatal explosions and fires earlier this month in the Merrimack Valley.

Emergency responders converged on Lawrence, Andover and North Andover on Sept. 13 after gas explosions and fires linked to a system overseen by NiSource Inc. unit Columbia Gas of Massachusetts killed one man, injured about 25 people and destroyed or damaged dozens of homes. The National Transportation Safety Board is investigating, and Columbia Gas has a “massive replacement program” of the area’s system underway.

The Massachusetts Department of Public Utilities (DPU) on Wednesday said it would use state of emergency authority granted by Gov. Charlie Baker to “direct all natural gas distribution companies operating in the commonwealth to fund the statewide examination.” The DPU action “is intended to assess, out of an abundance of caution, the safety of pipeline infrastructure throughout the commonwealth and follows a similar precedent set by the state of California to conduct a third party review following a natural gas incident in 2010.”

A power glitch at the Pacific Gas & Electric Co. (PG&E) natural gas terminal in Milpitas, CA, was blamed in 2010 for opening a pipeline control valve, which in turn caused a surge in pressure before the San Bruno, CA, gas pipeline ruptured, killing eight people. In addition to state fines and years of investigations, PG&E was found guilty two years ago by a federal jury in San Francisco on five of 11 counts for violating gas pipeline safety regulations related to the tragedy.

“The safety and security of all communities is the top priority of our administration, and out of an abundance of caution, I have directed the utilities to work with an independent evaluator to carry out this comprehensive safety review,” Baker said of the planned DPU evaluation in Massachusetts. “This review will help improve accountability for utilities and add another layer of oversight for all natural gas infrastructure.”

DPU Chair Angela O’Connor said regulators work continually “to ensure the safety of residents and the commonwealth’s energy infrastructure, and the independent evaluator’s review will further the department’s efforts by performing an additional examination of the physical condition and safety of the distribution system, as well as the operational and maintenance functions of natural gas companies.”

Once selected, the independent evaluator would be instructed to examine the physical integrity and safety of the gas distribution system, as well as “the operation and maintenance policies and practices of all natural gas distribution companies operating within the commonwealth.”

Additionally, the evaluator is to report with any “necessary recommendations” at the end of the contract. The examination is to “complement but not duplicate” the investigation by the NTSB.

The DPU plans to hire the evaluator through an expedited procurement in consultation with the Pipeline and Hazardous Materials Safety Administration, which has granted state regulators delegated authority to conduct pipeline safety activities.

The scope of the independent evaluator’s assessment, with respect to physical distribution, is to analyze:

The portion of the assessment related to operating and maintaining the distribution system is to examine gas distribution companies’ “written operation and maintenance policies and procedures for their respective distribution systems, including safety protocols and incident response.”

In addition, the assessment is to review “whether there are sufficient personnel, including inspectors, and management structures and communication protocols in place” at the distribution companies to ensure that safety and incident response protocols may be operationalized.

The assessment also is to analyze operating pressure protocols, including maximum allowable pressures and procedures in the event of abnormalities, compliance with the state’s “Dig Safe” statute and gas companies’ recordkeeping.