On March 20, MSHA announced it was assessing $420,300 in fines for flagrant violations at the Tower mine, also known as the Aberdeen mine, which is operated by a subsidiary of Murray Energy.

Both the violation at West Ridge announced by MSHA on Monday and the Tower violations stem from the accumulation of potentially explosive material.

In the case of the West Ridge mine, coal dust had accumulated in the crusher building and the company was ordered on three occasions - in December 2006, January 2007 and in January 2008 - to clean it up.

"The mine operator has demonstrated repeated indifference to comply," wrote Don Gibson, assistant district manager for MSHA's District 9. "Mine management has been warned and was put on notice that greater efforts were needed to control the coal dust."

MSHA assessed a $4,800 fine for each of the previous two West Ridge violations. Both are delinquent. The agency has not assessed a fine in the latest violation, but since it is deemed as flagrant, the agency could impose a fine of up to $220,000.

MSHA defines a flagrant violation as "a reckless or repeated failure to make reasonable efforts to eliminate a known violation of a mandatory safety and health standard that substantially and proximately caused, or reasonably could have been expected to cause, death or serious bodily injury."

The company did not respond to e-mails seeking comment.

MSHA found that the Tower mine contained unacceptably high levels of coal dust and liquid hydrocarbons, both of which are potentially explosive.

Last week, UtahAmerican Energy Inc., which operated the Tower mine, said it was closing the mine because of unexpected structural issues. Tower was the deepest operating mine in the United States and had experienced problems with mining coal at such extreme depths.

gehrke@sltrib.com