(CN) - The federal judge overseeing the trial of former Massey Energy chief Don Blankenship granted the government's motion to exclude evidence related to the company's disagreement with a regulation on mine ventilation.
Blankenship, 65, is charged with conspiring to break mine safety rules at the Upper Big Branch mine boost production at the facility. A massive explosion there in 2010 killed 29 miners and led to an investigation that uncovered a host of problems.
U.S. District Judge Irene Berger on Oct. 6 granted the government's motion to exclude "claims that federal mine safety standards were incorrect, misguided, or imprudent."
The prosecution then filed a motion asking Berger to exclude defense arguments during opening statements and cross-examination which might seek to establish that the Mine Safety and Health Administration forced the Massey Energy Upper Big Branch mine to adopt a ventilation plan that did not use "belt air."
Belt air is the practice of bringing air into mines for miners to breathe through the same tunnels used to take coal out of the mine on conveyor belts.
The federal regulation governing use of belt air in the ventilation of a mine's working face, 30 C.F.R. §75.350(b), states that belt air may be used to ventilate a "working section" of a mine only when "evaluated and approved by the district manager in the mine ventilation plan."
In opposing the motion, attorneys for Blankenship acknowledged they would seek to introduce evidence about the difficulties Massey encountered in attempting to comply with the agency's mandates about the use of belt air at Upper Big Branch, and Massey's disagreement with these mandates.
The defense claimed that such evidence "bears directly" on the "cause of citations issued during the indictment period" and also "bears on the relationship between MSHA and Massey."
Judge Berger sided with the government.
"The plain language of this regulation requires MSHA to evaluate mine ventilation plans that propose using belt air to ventilate the mine's working face, and to reject plans that run afoul of federal mine health and safety regulations," Berger wrote. "Evidence and argument that Massey disagreed with MSHA's enforcement of the belt air regulations at Upper Big Branch is inadmissible.
"The same is true of evidence and argument that MSHA 'forced' the Upper Big Branch mine to adopt a ventilation plan that did not use belt air," Berger continued. "Such evidence clearly falls within the Court's prior ruling on 'claims that federal mine safety regulations were incorrect, misguided, or imprudent,' and must be excluded."
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