How far away does a gas leak have to be to cause a blast? Here’s how it works

SOUTH JORDAN – A new preliminary report from the NTSB into this month’s deadly house explosion in South Jordan revealed the gas leak didn’t start from the house. It originated under the street 150 feet away from the home. So, how far away could a leak actually cause an explosion?

KSL TV spoke with firefighters to better understand the distance a dangerous leak could travel, and discovered the length, in this case, wasn’t abnormal at all.

To cause a deadly blast like the one in South Jordan, firefighters in Draper said you need distance to make gas leaks more dangerous.

“Where it gets out toward the edge of the leak or cloud, that’s where you’ll have an ignitable mix of the gas and air,” said Batt. Chief Cody Jolley with the Draper Fire Department.

So how far away could the edge of a leak cause a blast?

“If it’s a high volume of gas that’s coming out of a line, it could go really far. I couldn’t say exactly, but a couple hundred feet potentially,” Jolley said.

According to the NTSB report, the South Jordan leak started under the middle of the road and then snaked its way 150 feet into the house.

“The biggest danger with natural gas is when it’s confined in something like a structure or underground,” Jolley said.

And making it even more dangerous, from the distance the gas traveled, firefighters said it’s possible the rotten egg smell added to the gas, to warn you of a leak, could have gone away.

“The more it mixes with air, the more tendency it’s going to want to dissipate everything, yeah,” he said.

South Jordan encouraging homeowners to purchase gas detectors after deadly blast

Firefighters said part of the reason the smell could go away is because the added odor is heavier than the gas, and the further away it goes, the more the two want to separate.

It’s unclear if that’s what happened in South Jordan, but firefighters warn that if you smell that rotten egg smell, don’t hesitate to give them a call.