DEP officials said they were taking actions to respond to OSM's concerns.
The second report, leaked to the media in summary form, described poor construction techniques, lax quality control for safety testing, and inadequate compaction of embankment materials at impoundments in West Virginia.
OSM has said those results are not final, and the DEP has disputed the findings contained in the leaked summary.
Last November, a United Mine Workers member, dozer operator Markel Koon, 58, of Shinnston, was killed when he was swept into a CONSOL Energy impoundment when part of a dike under construction collapsed.
The state Office of Miners' Health, Safety and Training cited the company, saying that the embankment "was not constructed or maintained in a manner to ensure safe operation of mobile equipment."
Lawrence Messina, a spokesman for the state Department of Military Affairs and Public Safety, criticized the protesters.
"This was the wrong way to do things, and as a result, we've had maybe a dozen Charleston firefighters on campus [at the Governor's Mansion] and at least two trucks that hopefully were not needed elsewhere in this city," Messina said. "It's definitely a public safety concern."
The mansion sits on Statehouse grounds and there is no security gate restricting public access to it. Messina said there have been discussions in the past about enhancing security on the Capitol Complex campus and that those conversations are "ongoing."