Dive Brief:

• The Massachusetts Department of Public Utilities (DPU) has ordered National Grid to halt all non-essential work on its gas distribution system, after a utility worker briefly overpressurized the system during routine maintenance in the city of Woburn.
• The incident follows a deadly series of explosions in northern Massachusetts last month that killed one and injured 10 while setting fire to 70 homes. Overpressurization on the Columbia Gas system is the suspected cause.
• DPU officials say the moratorium will remain in place until National Grid's safety practices have been reviewed.

Dive Insight:

Massachusetts energy officials are on high alert when it comes to gas issues following last month's disaster on the Columbia system, and they shut down National Grid's work once word of the overpressurization incident came out.

National Grid said Tuesday the incident was brief, no customers were evacuated, and the mistake was corrected within a few minutes. However, the DPU has ordered National Grid to have an inspector on hand for any work that could lead to overpressurization, according to local media.

The city of Woburn put out a statement saying approximately 300 homes had gas service cut off and "the incident is isolated to those homes only and the area is safe."

National Grid said there was "no apparent damage to the system," which fed the impacted homes through three miles of gas pipeline. "Pressure-control devices at each property function as an extra safety measure to limit the flow of gas to safe and normal levels," the utility said in a statement.

National grid said it expected to be bringing customers back online Wednesday with the work completed by Thursday.

Columbia Gas, following the series of explosions on its system last month, has offered to pay for customers to switch from natural gas to another source for heating.

Those explosions hit the towns of Lawrence, Andover and North Andover, where Columbia Gas says it will replace about 45 miles of pipeline. In the immediate aftermath, almost 9,000 homes were without natural gas service.

The DPU's decision to limit National Grid's pipeline work and to require observers, fits alongside its approach to September's disaster. In the aftermath, Gov. Charlie Baker, R, put Eversource Energy in charge of recovery from explosions, finding Columbia Gas was not prepared to tackle the challenge.