Kevin Stricklin, head of coal mine safety, will walk senators through the steps the Mine Safety and Health Administration took before approving the plans to cut into the 500-foot thick coal barriers that were helping to support the roof, according to his prepared testimony, obtained by The Salt Lake Tribune.
Stricklin's comments come as the Senate Health, Education, Labor and Pensions Committee begins its inquiry into the August mine collapse that entombed six miners - Kerry Allred, Don Erickson, Luis Hernandez, Juan Carlos Payan, Brandon Phillips, Manuel Sanchez - and into the later bump that killed three rescuers and injured six others.
The House Education and Labor Committee is scheduled to hear Wednesday from five of the deceased miners' family members and Utah Gov. Jon Huntsman Jr.
Discussions of mining the thick coal walls first took place in the spring of 2006, Stricklin says, before Crandall Canyon was purchased by UtahAmerican Energy and Robert Murray. Murray bought the mine in August 2006, and requested approval in January to do retreat mining - a practice in which the pillars supporting the roof are cut away allowing the roof to fall in - in the coal barriers.
As part of its review, MSHA looked at technical analyses done by Agapito Associates Inc., a Colorado based engineering firm, requesting clarification on some issues in the report. The agency then sent its own experts to Crandall Canyon to observe conditions and recommended some changes, Stricklin said.
The company said last week it would not address issues relating to approval of its mine plan while MSHA is investigating the matter.
The retreat mining plan was approved in February, and work progressed until March, when a major bump - where pressures in the mine cause coal to burst from the roof or pillars - significantly damaged the mine and prompted operators to abandon efforts to recover the pillars in the north barrier.
Stricklin says the bump was not officially reported to MSHA; the company maintains it didn't have to report the event. The MSHA investigation will consider whether the event should have been reported, Stricklin said.
Despite the problems retreat mining in the north barrier, when mine operators asked MSHA to approve a similar plan in the south barrier, it was quickly OK'd on June 15.
MSHA experts recommended against cutting away eight pillars in the south barrier to protect ventilation tunnels. The pillars are in the area where the six miners were working on Aug. 6 when a massive bump caused a major collapse, trapping them underground.
Robert Ferriter, director of the Mine Safety and Health Program at the Colorado School of Mines, said that, given the problems that were experienced in the north barrier and the similarities in the type of mining and conditions, "one could reasonably anticipate the occurrence of additional coal mine bumps.
"The risk was quite clear," Ferriter said in his prepared testimony.
Ferriter quotes several reports by a Bureau of Land Management inspector, noting deteriorating conditions, bumps and roof falls in the area being mined.
BLM had already refused in 2004 to allow mining of the pillars between the barriers, determining the enormous pressures had caused them to deteriorate so badly that the plans to try pillar recovery were "wishful thinking."
But when it came to mining the barriers themselves, BLM allowed work to proceed but urged caution.
Ferriter said that, based on the BLM reports, "It is obvious that mining conditions in the barrier pillars were extremely hazardous, yet removal of coal pillars from the barrier pillars continued."