Excess coal dust found inside doomed West Virginia mine

West Virginia's Upper Big Branch (UBB) mine contained excess amounts of combustible coal dust when an explosion ripped through it with deadly results in April, the Mine Safety and Health Administration (MSHA) revealed Friday.

Kevin Stricklin, MSHA's head of coal mine safety, told reporters that 1,423 samples taken from the Massey-owned mine after the blast — representing roughly 80 percent of all samples taken — were out of compliance with MSHA coal dust standards.  

Under current rules, mine operators are required to dilute coal dust through a process known as rock dusting (which usually means dousing mine walls with limestone dust). Rock dusting should occur throughout the day, to make the highly combustible coal dust inert in case of an explosion.  

Some Massey miners, however, have said the company discouraged frequent rock dusting, which distracted workers from what was supposed to be their central focus: mining coal. 

Former Massey miner Chuck Nelson, for instance, said rock dusting was commonly done only at the end of the shift — or after miners were warned that safety inspectors were on site.

"They call and tell us to start hanging our curtains, start cleaning the coal dust up, start rock-dusting the ribs — get everything right because he’s on his way in there," Nelson said in an interview from his West Virginia home earlier in the year. "But as soon as they’re on their way outside — before they get outside — these line curtains are jerked down again. They’re back to doing the same old business as usual."

The official cause of April's UBB disaster, which killed 29 miners, has yet to be identified. But based on the sheer size of the blast, mine safety experts suspect that ignited methane, combined with the presence of coal dust, is the culprit.

Stricklin said Friday that more samples than 80 percent would likely have failed MSHA's tests just before the blast, which would have burned up much of the coal dust.

The details about the UBB's non-compliance with MSHA's coal dust standards were first reported Thursday by The Charleston Gazette's Ken Ward Jr.