The Select Board on Monday heard from the town’s fire chief and an Eversource representative about a gas main leak that occurred on Dec. 8 at the Eversource liquefied natural gas facility on Wilson Street.

The town sent out a statement on the day of the incident. It highlighted the quick response by the Hopkinton Fire Department. The situation was similar to what had occurred at a large-scale training drill at the facility in May 2023. It also stated that there was no danger to the public at any time.

The Independent reached out to HFD Chief Gary Daugherty and Eversource on Dec. 10 with follow-up questions but received no response.

HFD response recapped

Chair Joe Clark said he thought it was important for the town to hear about what happened from those involved to give residents “peace of mind around this incident.”

Daugherty explained that a call came in at around 9:30 a.m. that day reporting a gas leak in the area of 52 Wilson Street.

“We upgraded the response from just an engine company to a full first alarm because it was coming in from the plant,” he said.

Firefighters were met by LNG staff members, who led them to the leak. The HFD started vapor suppression in coordination with the plant’s staff. Firefighters also set up air monitoring systems.

“Eversource actually identified the leak and shut down the flow to that pipe,” said Daugherty.

The fire chief added that the Department of Fire Services Hazardous Materials Emergency Response Division also responded to provide additional air monitoring stations throughout the nearby neighborhoods.

Stressed Daugherty: “At no time did we get any type of gas readings outside of the immediate area of the leak.”

The incident was terminated at about 5 p.m., he added. It took several hours for the 1,500-foot pipe to be drained.

LNG director explains situation

Jim Blackburn, Eversource’s director of liquefied natural gas (LNG), explained the facility’s layout to the board. It consists of three LNG storage tanks that store the liquefied gas. The gas is purchased during the summer, when prices are lower, he said. Eversource draws on those tanks in the winter. He compared the process to electric battery storage.

He noted that the plant is “extremely important” because it is the largest of Eversource’s 10 LNG facilities in New England.

Blackburn said the leak was discovered at 9:18 a.m. on Dec. 8. Staff immediately shut down the pumps and implemented an emergency shutdown plan within two minutes. It initially was thought to be a water leak.

As the pipe leaked, the liquid became vaporized, he added. The line and the area around it were isolated to prevent the gas from igniting. It took several hours for the vapor to drain out of the line, which then was “purged from service.”

Added Blackburn: “From our perspective, I think the emergency response actually worked very well.”

Blackburn said the event happened on the “uphill side” of Wilson Street, the older part of the facility. Located at 52 Wilson Street, this section was constructed in 1967. The three tanks were built in the mid-1970s.

The line transported the gas to the vaporizers at 55 Wilson Street, he added.

Because the line has not been modified since its installation, Blackburn said the facility’s capital plan called for upgrading the pipe supports this coming summer. The update might have prevented this situation, he noted.

Kizner blasts LNG rep

Member Matthew Kizner asked about the results of an internal investigation by Eversource. Blackburn said it has not been concluded yet. A report will be shared with the Department of Public Utilities (DPU) and a federal regulatory commission, he added.

“I would imagine and hope that there has been a significant after-action here,” said Kizner, “given that you had a large-scale unintended gas leak and discharge in an immediate civilian population area of a potentially life-threatening material.”

Since the event, Blackburn said an examination showed the “high-stress area that ultimately resulted in this failure.” A second “failure” at an “upstream location” may have led to the leak. Another minor repair was made at a third site.

Kizner asked if a review of the pipe’s anchor points is part of “routine maintenance.”

Said Blackburn: “Going forward, it will be.”

“It’s hard to feel a strong degree of comfort with this facility given that you seem to be learning about its inadequacies in real time here,” responded Kizner.

Blackburn said a pipe support inspection plan will be implemented as part of the facility’s maintenance procedures as a “lesson learned.”

Member Brian Herr asked how many safety professionals are on-site at the plant daily. Blackburn said there are none.

Blackburn added that the plant is “currently offline from vaporization” until the pipe is repaired. He hopes to be able to start up again next week if the DPU approves.