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October 23, 2020 C-1980-007/West Elk Mine LDS <br />are approximately 100' apart. The fifth, fourth and third entries had been or were being backfilled at the time of <br />the inspection, and would be sealed - the final design of the bulkhead seals will require MSHA approval. The <br />second entry had not yet progressed as far south as those to the west, and the first had already been dropped as it <br />was no longer required to satisfy ventilation requirements. <br />At the time of the inspection contractors with RACS, LLC. of Delta, CO were on site, with a small <br />pneumatic drill rig mounted on a skid -steer. The drill rig was being used to construct holes to grout the backfilled <br />material with the aim of reducing its permeability. The holes were being constructed using the "casing advance" <br />technique, which is effective in unconsolidated material. A 5.5" casing is advanced in 5' lengths, with the drill <br />stem inside of it. When the hole reaches consolidated material it is advanced a little further (8-12"), then the drill <br />stem is withdrawn while the casing remains in place. The first section of casing is withdrawn and cement grout is <br />poured into the hole with a bucket. This process is repeated until all of the casing has been removed and the hole is <br />full of grout. At this point a steel plate with a pass -through port is placed over the hole and held down with the <br />bucket of a back -hoe, the cement grout is then pressurized to approximately 150 psi using a grout pump, forcing it <br />into the pore space of the fill material. The contractors were working on the second hole at the time of the <br />inspection. Mr. Poulos expected that a total of 8-12 holes would be constructed in all and estimated that the total <br />depth of the first hole was around 30' (thirty feet) and that it had been completed to the roof of the coal seam <br />rather than the floor. <br />SUPPORT FACILITIES - Rule 4.04: <br />No recent work had taken place on the MVB pads, holes and roads for the SS2 panel and the gate <br />remained locked. <br />A row of sandbags had been placed for sediment control around the perimeters of the SS and SS2 pads. <br />The use of sandbags to control runoff from the pads is not required by the mining permit (C1980007). Fresh straw <br />bales for sediment control had been placed along the roads accessing the pads. <br />The mobile flare was in operation on the the SS1-5 pad. Mr. Poulos was able to monitor the concentration <br />of methane in the stream of gas coming from the borehole, its flow rate, and the temperature of the flame (to <br />verify complete combustion), using his phone. <br />DOCUMENTS RECEIVED <br />N/A <br />OTHER (SPECIFY) <br />N/A <br />Number of Partial Inspection this Fiscal Year: 5 <br />Number of Complete Inspections this Fiscal Year: 1 <br />Page 3 of 24 <br />