The 4th U.S. Circuit Court of Appeals on Thursday affirmed former Massey Energy Co. CEO Donald Blankenship’s conviction for conspiring to violate federal mine safety laws and regulations. 

Mr. Blankenship was sentenced to a year in federal prison last April and ordered to pay a $250,000 fine for his role in the Upper Big Branch mine explosion in West Virginia that killed 29 miners in 2010. He was acquitted of all felony charges, but convicted of a misdemeanor conspiracy charge for willfully violating U.S. mine health and safety standards.

The U.S. Mine Safety & Health Administration repeatedly cited Massey for violations at the Upper Big Branch mine, with MSHA identifying 549 violations in 2009 alone and the mine receiving the third-most serious safety citations of any mine in the United States, according to court documents. Many of these violations related to improper ventilation and accumulation of combustible materials — problems that were key contributing factors to the accident. 

Mr. Blankenship was aware of the violations at the Upper Big Branch mine in the years leading up to the accident, receiving daily reports showing the numerous citations for safety violations at the mine, according to court documents. He also received warnings from a senior Massey safety official about the serious risks posed by the violations at Upper Big Branch.

The appeals court rejected Mr. Blankenship’s contention that the U.S. District Court in Beckley, West Virginia, should have dismissed the indictment and that it violated his Sixth Amendment rights by denying him the opportunity to engage in additional cross-examination of a key witness. It also rejected arguments that the District Court errantly instructed the jury regarding the meaning of “willfully” violating federal mine safety and health standards and that the court’s instructions improperly permitted the jury to convict him even if he did not know a particular act or omission would lead to a violation. 

“After careful review, we conclude the district court committed no reversible error,” the Richmond, Virginia-based appeals court said in its ruling published on Thursday. “Accordingly, we affirm.”