AML targets Reliance mine void

In some locations across Sweetwater County, the remnants of the county’s rich coal mining heritage can still be found in the numerous mine voids beneath the mining towns founded to extract coal needed to feed the Union Pacific trains.

In Reliance, a large mine void is causing Abandoned Mine Lands officials to plan a multiphase effort to mitigate it before it can cause any damage. The void is the result of undermining beneath the town and threatens both the county road and water line running through the town, and is believed to be beneath a few residences as well.

The problem is compounded by the fact that a mine fire burning beneath the town is burning away the pillars supporting portions of the old mine.

“The fires in Reliance started in the 30s; they’re still burning,” Doug Beahm, principal engineer with BRS, an engineering firm working with the AML, said.

The fires have burned for more than 80 years because while fire will consume the oxygen inside of a mine, a vacuum forms and creates vents at the surface to feed air into the mine. Because of the heavy rains the area experienced earlier this year, subsidence has also increased, with voids opening up in several locations across the county, including Reliance. Beahm said Reliance also has a unique problem in that the mines in Rock Springs would mine a 6 or 7-foot seam of coal, but the seams in Reliance were up to 12 feet thick. The mines utilized larger rooms than those found in Rock Springs.

Beahm said the depth of the void is approximately 50 feet from the surface, which he says is not enough cover for the void. AMl plans to use a grouting material to seal the fire away from the town’s water line and push it away from the pipe. They’ll also fill the voids with grout to prevent larger holes to open at the surface. The work is projected to cost roughly $29 million.

“If there’s an area in the whole United States that deserves AML consideration, it’s Reliance,” Commissioner Wally Johnson said about the town. “Most of us wouldn’t be here if it weren’t for those voids.”