Multiple Leaks Spur Emergency Shutoff of Nat. Gas to All of Hinsdale

Hinsdale has been without natural gas services since March 19 after multiple leaks were reported and detected in the community raising concerns that the problem was widespread and required the company to halt services.

According to Montana-Dakota Utilities spokesman Mark Hanson, the decision to halt services was made on Friday and the community was notified of the interruption and a plan to fix the pipes was initiated. Hanson told the Courier that the company received a call early last week concerning gas odor. That call was followed by a few other calls that led the company to dispatch a leak survey crew to check the town. During the survey the crew discovered multiple leaks across the whole of the community and after excavating portions of pipe they determined that the infrastructure was "not in the best of shape" according to Hanson.

"We ended up finding multiple leaks," explained Hanson. "It was at a point where, for safety concerns, we shut down the gas flow on Friday evening about 5:30. And we're doing a complete replacement of the gas system in town."

The cause of the leaks is currently unknown. Hanson said the company is focusing on restoring services to the 135 customers effected by the outage before they investigate the cause. He did say that it is possibly due to corrosion on the steel pipes that were installed in the 1960s, but he could not say for certain.

Over the weekend (March 20 and 21), the company finished preconstruction work to include engineering, sourcing contractors and prepping and surveying the new pipe routes as well as the existing utility infrastructure. As of March 22, the company was making preparations to bore a new pipeline into the ground beginning with a mainline that will run off of the natural gas pump site near the veterans' hall down the alley towards the school. That construction was set to begin Monday evening.

Hanson said the pipe will have to settle for eight hours before it can be connected to existing businesses, schools or homes. Once that has occurred the company will restore service to the school and other customers along the route of the new pipe before adding pipe out to the remainder of the community.

"We have crews on site, and they are doing some prep work," Hanson said. "We had to get emergency locates for all the underground utilities done, which I think they have them done for the first few phases of out project."

A timeline for the construction was not available on March 22, and Hanson could not offer a timeline for the project. He did say that it will rely heavily on the conditions of the ground and how easily the new pipe can be drilled.

"We don't have an exact timeline yet, since we haven't really started," he explained. "Early indications are that it looks favorable for the type of soil and rock, but we'll know tomorrow (March 23) for our community meetings of what our crews have seen to that point. And we'll have a better handle on a complete timeline."

In the meantime, MDU has been providing electric space heaters to customers and businesses in the community to fill the heating gap for the time being. Heaters were also delivered to Hinsdale School. A community-wide meeting was also planned for Tuesday afternoon (after the Courier's print deadline) at the American Legion Post in Hinsdale where further details on the plan to restore service and the timing of the operation will be made available to the public. MDU will also be handing out more space heaters to customers who need them at that meeting.

MDU will be investigating the cause of the leaks in the future after services have been restored. Hanson said the pipes had been leak checked in 2018 and only one leak was detected during that survey. The company will also seek to answer why the leaks were all detected so close together and determine whether the cause was a concern. He added that it looks as though the existing pipelines were installed in the 1960s and that corrosion overtime is common for the steel pipes.

He also said leaks are commonplace across the company's infrastructure and the severity of leaks and the proximity to buildings usually determines the immediacy of the problem and whether the company monitors it-such as in the case of small, isolated leaks-or whether it requires immediate repair-such as when it is a large leak or near a structure. Companies are required to leak survey pipes regularly as part of federal regulations. According to MDU, the leak surveys are performed annually for all the areas designated as Business Districts and on a four-year rotation for all areas outside of Business Districts. Federal regulations require a five-year rotation; however MDU uses a more stringent four-year rotation..

An emergency project of this scale is also unprecedented, explained Hanson. The utility's spokesman said that while pipelines are constantly being replaced or repaired this was the first time an emergency replacement was being done to an entire community simultaneously. It was also the first time numerous leaks were detected across a community without a discernable cause or proximity.

"When they did the leak survey it wasn't concentrated in a certain area," explained Hanson. "So, the decision was made we're just going to replace everything and ensure that the whole system is safe."

MDU also does not believe the problem extends beyond Hinsdale either. Given the 2018 Hinsdale leak survey results and the scale of the current problem, the company will be looking at the causes and deciding future actions but at present they believe Hinsdale to be an isolated case that does not affect other communities.

"It's something that's not normal that's happened, and we need to nail that down first," Hanson said. "But we don't believe that it's anything [that has happened] outside of this community."