Assistant Secretary of Labor for Mine Safety and Health
Internal Review Report - Big Branch Slurry Impoundment Failure
January 21, 2003
In the early morning hours of Wednesday, October 11, 2000, an inrush of water and slurry poured from the Martin County Coal Corporation's Big Branch impoundment into the adjacent 1-C underground mine. An estimated 306 million gallons of slurry flowed from the impoundment into the mine. The slurry burst through the mine portals and flowed into tributaries of the Big Sandy River, visibly contaminating waterways as far downstream as the Ohio River.
While no one was injured in the incident, significant environmental damage resulted. It was fortunate that no fatalities occurred. In fact, a mine examiner had exited the underground mine only 15 minutes before the slurry breakthrough.
MSHA completed its investigation into the slurry spill incident in October 2001. The investigators found that Martin County Coal Company failed to follow its approved sealing plan for the impoundment. As a result, seepage led to internal erosion between the impoundment and the underground mine. While warning signs of increased seepage were present, the company failed to take action before catastrophic failure occurred. MSHA's investigators issued two citations to Martin County Coal Company, for "unwarrantable failure" violations directly contributing to the incident. These violations were assessed the maximum civil penalties allowed by law.
At the time we released the incident investigation report, I also stated that we needed to do more -- we needed to review and improve the way MSHA oversees these impoundments. I ordered an internal review into MSHA's management procedures and inspection practices prior to this incident at the Big Branch impoundment and impoundments nationwide.
The purpose was to determine if MSHA's management systems were adequate, and how they could be improved. A better managed MSHA will mean greater safety for miners.
I appointed an internal review team composed of well qualified MSHA personnel from outside the district where the incident occurred and independent of the investigation team. The group reviewed existing policies and procedures, inspection records, and data in MSHA's computer system. They also interviewed employees with personal knowledge of pertinent events.
Their review and recommendations are now complete. Today I discussed the results with all the employees in MSHA's District 6, and we have already started taking action on the findings.
The internal review team focused on two main areas: approval of plans for impoundments, and inspection of those impoundments. They identified several systematic weaknesses, which we already have corrected or are correcting.
Among the significant findings, at the time of the Big Branch slurry spill MSHA:
- Needed national guidelines for impoundment plan approval;
- Had a backlog of impoundment plans awaiting review;
- Was not always consistent in the frequency, quality and documentation of impoundment inspections; and
- Had issued a large array of information, policies and instructions on impoundment safety over many years.
As a result of this internal review, MSHA has already taken appropriate action in some areas. To eliminate backlogs, we are adopting new procedures under which significant new impoundment plans will get prompt review by Technical Support specialists, while more routine modifications are handled locally. In addition, we are working to clarify and consolidate all of the numerous directives on our books and will issue a new impoundment inspection handbook.
The internal review team also noted that MSHA has no established method to verify the full extent of underground workings as depicted on mine maps. This also was an issue in the Quecreek Mine inundation in Somerset County last summer. Recently we held a technical symposium to collect information on new technology that may provide answers. We are pursuing several promising suggestions.
During 2001 and 2002, the U.S. mining industry had its two safest years on record. We need to maintain that momentum and build on it. Now our goal is to make safety a value throughout the mining industry and take the industry to the next level in safety and health performance. When we strengthen MSHA's own management process, that means we can make more effective use of all the tools provided in the law - enforcement, education and training, and technical assistance.
MSHA Publishes Internal Review on Kentucky Slurry Spill Agency Acts to Eliminate Weaknesses
Martin County Coal Corporation (PDF)