The violations are included in a report released Thursday by the state Office of Miners' Health, Safety and Training. Officials planned an afternoon news conference to discuss the fourth and final report on the nation's worst coal mining disaster in four decades at Massey Energy's mine near Montcoal.
The report comes the day after federal prosecutors charged the mine's former superintendent with fraud and signaled they are going after other Massey employees, likely higher up the management ladder.
The state's conclusions about the cause of the explosion largely mirror those of previous reports: The machine cutting through sandstone to reach the coal created the heat or spark that methane needed to ignite. Broken water sprayers then failed to stop the fireball from turning into a much more powerful series of explosions fueled by coal dust.
The state's report said foremen Ricky J. Foster and Terry W. Moore repeatedly failed to clean conveyor belts and apply rock dust to certain areas in the mine from December 2009 until the explosion on April 5, 2010. Mine operators use pulverized limestone to cover and neutralize highly explosive coal dust.
One of the "most disturbing facts" investigators said they learned about rock-dusting practices at Upper Big Branch was the failure to treat one side of the longwall mining machine during the eight months it operated. Some 5,400 feet of the 6,700-foot-long coal panel was mined between September 2009 and April 2010 "without any record of rock dust being applied," the report said.
Both foremen signed safety inspection logs to indicate they were aware of coal dust accumulation and the need for rock dusting, the report said, but there is no record suggesting either fixed the problems. The log books also had "lack of clarity and full disclosure" about the extent of the hazards underground.
"Extreme brevity of information was used on a daily basis," when more detail could have helped workers on subsequent shifts protect themselves, the report said.
State law proposes only $250 fines for individual violations, but the agency could seek suspension or revocation of the foremen's licenses and certifications.
"Individuals involved in the day-to-day decision making at the mine must be held accountable regardless of their title," the report said. "The mine foreman is the highest-ranking official that current state law addresses."
Neither Foster nor Moore cooperated with investigations by the federal Mine Safety and Health Administration and the United Mine Workers. They are listed among 18 Massey executives and mine managers who invoked their right to avoid self-incrimination and refused to testify.
The superintendent charged Wednesday did the same.
Gary May, 43, was charged with conspiracy to defraud the federal government, accused of disabling a methane monitor on a mining machine and falsifying safety records. Prosecutors said May also manipulated the mine's ventilation system during inspections to fool safety officials about air flow.
He could get up to five years in prison if convicted.
May is the highest-ranking company official charged so far.
The other, former security chief Hughie Elbert Stover, will be sentenced next week for lying to investigators and trying to destroy documents. U.S. Attorney Booth Goodwin is urging a federal judge to make an example of Stover by giving him the maximum - 25 years in prison.
The charges against May were contained in a federal information, a document that typically signals a defendant's cooperation with prosecutors. May has declined comment.
The state's report said methane, which occurs naturally in underground mines, was coming from several sources, including cracks in the floor.
Massey, bought out last summer by Virginia-based Alpha Natural Resources, has long argued that a sudden inundation from a crack overwhelmed all safety systems.
The state acknowledged the crack was likely "a major source of gas" and noted it was linked to three previous methane releases and ignitions. But like MSHA, it rejected Massey's theory, saying the gas is easily moved by air currents, and air flow at the main production area was about 700 feet per minute before the blast.
The report said the gas apparently collected behind roof-supporting shields on the longwall machine, and a nearby roof fall obstructed the air flow, allowing that accumulation to go undetected.
