Dominion pipeline safety discussed
Twin 36-inch pipes stretch across Calvert, Charles counties
Dominion Transmission sponsored a pipeline safety workshop Oct. 6 in Solomons for its 48 miles of natural gas pipeline that meanders across Calvert and Charles counties and into Virginia to connect with the national grid.
While the information session was open to anyone, it was geared toward excavation contractors and first responders to get them thinking and working together with the pipeline operator to be able to tackle accidental breaks, leaks and explosions in the twin 36-inch pipes — as well as other, smaller distribution lines. Twenty people, including two representatives from Dominion, attended the session at the Holiday Inn Solomons Conference Center and Marina.
“You’ve got to be able to work on the fly. You’ve go to work together,” said Brian Hedgecock, a
presenter with Paradigm Liaison Services, the company hired by oil and gas companies to host information workshops.
“In a small, rural area, without a lot of resources, you need to get together and work out what needs to be done,” Hedgecock said, speaking from experience as a Kansas state trooper who handles a bomb sniffing dog.
Along with the large gas transmission lines, there are also networks of smaller distribution lines in the area, as well as other buried utilities, that require the need for contractors to call 811, which is “Miss Utility” in Maryland — but is used across the nation under other names.
“It’s in every state in the United States of America,” Hedgecock said. “If you dig in Mother Earth, you’ve got to call 811. It’s state law.”
Hedgecock explained that contractors or homeowners are required to call two business days before any digging so company officials can inspect to make sure there are no pipelines or other utilities that could be damaged by the excavation.
While smaller gas lines are dangerous if they’re pierced, a problem with the two large gas transmission lines could result in an immediate impact area nearly 800 feet from the break and an “evacuation radius-radiant heat” zone of 2,600 feet, or a half mile, according to the PowerPoint presentation at the session.
Tom Israel, Dominion’s eastern area compliance coordinator, said 27 miles of the large transmission line in Southern Maryland is in “high consequence areas,” which for gas pipelines are areas that have population within the impact zone. Federal regulations require extra effort and analysis to “ensure the integrity of the pipelines” in those areas, according to the information booklet handed out at the session.
Dominion’s Claude Theis, the pipeline supervisor for Southern Maryland, said the transmission lines are automated in such a way that a drop in the 1,100 pounds-persquare-inch pressure from a leak or break would flag operators to pinpoint the leak and remotely close large valves — block gates — before and after the break to stop the flow of gas. There are seven block gates in the two lines in Southern Maryland about 8 miles apart.
“We’re very automated,” Theis said. “When we see a drop in pressure, it’s a red flag all over the place.”
A local fire official asked how long it would take for the gas to bleed down. Neither Israel nor Theis knew exactly, but said they’d get that information to the emergency personnel.
“It takes a long time. That’s a lot of gas,” Israel said about the volume of gas in the pipe between the blocking gates. Natural gas is lighter than air so even as the pressure diminishes, it will still burn into the air or dissipate if it hasn’t been ignited, he said.
A later video clip in the presentation concerning a natural gas incident advised fire crews to “let it burn,” because natural gas is colorless and odorless — the main transmission lines usually don’t have the “rotten egg smell” added like in distribution lines — and without the flame, it becomes an invisible hazard.
Hedgecock said one of the most important things the oil and gas companies can do is create relationships with local first responders to disseminate information and even train them so that, if an emergency arises, everyone is on the same page.
“I think that’s one of the things the oil and gas companies do that’s the most important,” he said.
Joe O’Neill of Hughesville, the safety officer at the Benedict Volunteer Fire Department and Rescue Squad, said he attended one the safety sessions in 2014 in Waldorf and shares what he’s learned with his fellow firefighters back at the station.
“It’s good to know these things and to be thinking about them,” the 45-year volunteer fire veteran said. “When I went back [the last time], I did an overview for the troops.
“To see the size of these pipes is amazing,” he added.
Brian Hedgecock of Paradigm Liaison Services talks about emergency response to natural gas pipeline incidents Oct. 6 in Solomons. The workshop was sponsored by Dominion Transmission Inc.