BEAVER — Federal regulators and the coal industry are struggling to come up with a new rule to strengthen underground mine seals.Under a new federal law, the U.S. Mine Safety and Health Administration has until Dec. 15 to finalize the rule.MSHA officials hope to publish a draft proposal sometime in May.“We’re diligently working toward that goal,” said Erik Sherer, an MSHA engineer working on the rulemaking. “This is a very steep learning curve for all of us.”During a meeting Thursday, coal industry officials complained that the changes being discussed could be too costly and time-consuming for mine operators.“We need a clear approval system,” said Jack Trackemas, director of technical services for Foundation Coal. “We don’t want to make it prohibitive to seal areas.”Last year, Congress ordered MSHA to toughen its mine seal standards after seal-related explosions in West Virginia and Kentucky killed a total of 17 miners.On Jan. 2, 2006, 12 miners died at the Sago Mine in Upshur County after lightweight foam block seals failed to contain an explosion inside a sealed-off part of the International Coal Group mine.On May 20, 2006, five miners died at the Kentucky Darby Mine when a cutting torch ignited methane that had leaked from behind a poorly constructed seal.
In the wake of the two disasters, mine safety advocates have revisited MSHA’s 1992 rule change that allowed seals to be built of “alternate” construction materials, such as the lightweight Omega Blocks used at Sago and Darby.Since 1969, federal law has required mined-out areas of underground coal mines to either be properly ventilated or “be isolated from the active workings of the mine with explosion-proof seals or bulkheads.”When it rewrote federal mine ventilation rules in 1992, MSHA decided to define “explosion-proof” as being able to withstand a blast of 20 pounds per square inch. At the time, MSHA cited a 1971 report from the federal Bureau of Mines as backing up that figure.But at an MSHA “Ventilation Summit” this week, Sherer, an agency senior engineer, said that the report does not really back up MSHA’s regulation.
“There’s not really a lot to support it,” Sherer said.In fact, the 1971 report noted that other countries had much stricter seal standards, and that explosions could be much stronger than 20 pounds per square inch.
Several hundred industry officials gathered for the two-day MSHA summit, held at the agency’s National Mine Health and Safety Academy outside Beckley. On Thursday morning, participants spent about four hours discussing mine seals.On Feb. 9, the National Institute for Occupational Safety and Health issued a draft report calling for federal mine seals to be able to withstand blasts of between 50 and 640 pounds per square inch, depending on whether mine operators monitor gases behind the seals and how large the sealed areas are.“The explosive forces are probably more dire than we had anticipated, said Karl Zipf, a NIOSH engineer and lead author of the agency’s report.As an example, Zipf said meeting the 640-psi standard would require a five-foot thick concrete seal for a 10-foot high mine tunnel.Zipf said NIOSH recommends that operators instead choose to more closely monitor the methane and other gases behind seals, a move that would allow seals to meet a standard of 50 or 120 pounds per square inch.“My recommendation, my preference, is to monitor and manage the atmosphere behind the seals and avoid construction of 600-psi seals altogether,” Zipf said. “If we don’t monitor, and allow anything to accumulate back there, that is an extremely dangerous situation.”
Trackemas said the coal industry prefers seal plans that require “no additional actions once [seals are] installed.”During a question-and-answer session, one industry official questioned whether any seals could actually be definitely called “explosion proof.”Sherer replied that he agreed, but that MSHA’s hands are tied by the “explosion proof” requirement of the federal mine safety law.“A lot of people talk about explosion-resistant being a preferred term,” replied Sherer. “Basically, I agree with that, but at the present time I don’t think we can do that.“It’s something we’ll have to run by our legal counsel during the rulemaking,” he said.