The report is part of a settlement made with the U.S. Department of Justice. As part of the settlement, the company also agreed to install significant new safety technology, create a trust to fund health and safety research, and take other steps to improve safety practices.

In the letter, a lawyer representing Alpha said the company began taking steps to improve Massey operations immediately after the June 2011 merger. The company says it has brought in special teams and outside consultants to assess and correct safety issues. It also says a significant number of staff was assigned to address compliance issues. As a result, Alpha said it has seen an overall decline in coal dust-related citations.