Blankenship said when used in gassy areas, those systems capture large amounts of methane behind longwall machines, where it can be recovered and piped to the surface, where it is sometimes sold commercially. In those mines, the large amount of methane present pushes above 15 percent of the atmospheric gases, out of the explosive range.
But, Blankenship argued, in less-gassy mines, these systems "may allow methane to linger" in the explosive range, which is roughly between 5 percent and 15 percent of the atmosphere.
Blankenship repeated Massey's complaints that the MSHA-mandated system refused the flow of fresh air at Upper Big Branch, and said agency officials had previously been "warned" about such problems by another company, Mach Mining LLC.
In September 2009, Mach Mining challenged two major citations in which MSHA inspectors alleged ventilation violations at the company's Mach No. 1 Mine in Illinois.
At that mine, Mach had wanted to deploy a "push-pull" ventilation system, with large fans pushing and pulling huge amounts of fresh air through the mine. The arrangement would have allowed Mach not to install as many other ventilation controls as mining advanced underground, the company believed.
But MSHA inspectors objected that the company had not, as required by new regulations, made a compelling case for why the mine needed to use its conveyor belt tunnel to bring fresh air into the mine. And, inspectors found -- as they also did at Upper Big Branch -- that airflow was reversed, with fresh air going in at least one location away from workers instead of toward them.
MSHA inspectors also wanted Mach Mining to more frequently evaluate the effectiveness of its ventilation system, by checking air quality in mined-out areas. Company officials wanted to simply check air as it flowed out of the mine.
In addition, MSHA inspectors found that Mach Mining was running two continuous mining machines on the same fresh-air supply, a violation of federal rules.
And they alleged that the company drove its latest longwall section too far in one direction, creating a "stair-step" effect that required additional ventilation controls to be safe.
In a January ruling, Administrative Law Judge Margaret Miller, of the Federal Mine Safety and Health Review Commission, upheld MSHA on those issues, and concluded that Mach Mining's ventilation plan "is not flexible or easily altered, making it difficult to meet changing needs as mining progresses."
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.