INSPEC03682 - Laserfiche WebLink

Home Browse Search

III. COMMENTS -COMPLIANCE Below are comments on the inspection. The comments include discussion of observations made during the inspection. Comments also describe any enforcement actions taken during the inspection and the facts or evidence supporting the enforcement action. This was a partial inspection of the West Elk Mine conducted on June 1, 2004 by Mike Boulay of the DMG. Mike Peacock of Mountain Coal Company was present during the entire inspection. Weather conditions were sunny and warm and ground conditions were dry. The purpose of this inspection was to observe permanent sealing of methane drainage wells. Plugging and abandonment procedures were observed at two methane drainage wells (15-3.5 and 16-04). Other sites were also inspected including an active methane drainage well (MDW) location and several reclaimed MDW sites: The MDW sites aze permitted as small azea exemptions with silt fence being the primary means of sediment control. The procedures utilized by MCC for permanent sealing of methane drainage wells include: • Placement of rubber bridge plug at the lowest point or until refusal in the blank well casing; • Running tremmie pipe into casing and determining depth of bridge plug; • Placing mixture of Hole Plug and water via tremmie pipe to a level approximately twenty feet above bridge plug and ensuring that gas flow to the surface has ceased; • Pumping approximately 100 feet of cement (Quick Crete) via tremmie pipe; • Filling remainder of hole to approximately ten feet below ground surface (bgs) with bentonite slurry; • Placing cement plug from ten feet bgs to within three feet of the surface and ---~----- --~a~'~anin ----- • Marking and surveying the hole. Lang Exploratory Drilling is the contractor being utilized for sealing the methane drainage wells. At MDW 15-3.5 the bridge plug hit refusal at 317 ft. bgs. The total depth of this MDW is 1196 ft. Pouring the final twenty feet of bentonite slurry was observed at this well. At MDW 16-04 the placement of the rubber bridge plug, running tremmie pipe and placing Hole Plug was observed. The bridge plug hit refusal at approximately 276.5 ft. bgs and the total depth of MDW 16-04 is 1105 R. The silt fence was slightly damaged at MDW 15-3.5. Please continue to maintain sediment control around the base of the small azea exemptions and make repairs to silt fence as needed to ensure compliance. Please ensure that the calculated well volumes of Hole Plug, cement, and bentonite slurry versus how much of each material is actually used to plug each MDW site is included in the abandonment reports submitted to the Division.