2014-07-24_PERMIT FILE - C1996083A (2)

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2.05.3 Retaining Wall Concrete retaining wall located at the B- Bench. The 8 -foot high retaining wall is approximately 50 -feet long. Hubbard Creek Shaft See Map 39 for the location of the ventilation shaft that was constructed during 2007 and 2008. It is lined with steel and has a finished diameter of 10.5 feet. The steel liner was cemented in place. Prior to drilling, the perimeter of the shaft was grouted to minimize water infiltration. Grouting was extensive in the collar area and was reduced when the shaft alignment encountered solid rock. The shaft was blind bored the entire depth of approximately 500 feet. The cuttings removed from the shaft are considered underground development waste and were therefore hauled to one of the approved gob disposal areas. The Hubbard Creek shaft has been backfilled and capped. Emergency Escape System During 2009 the Operator installed an emergency escape system over the Hubbard Creek Shaft. The hoist is 20 -feet long, 8 -feet wide and 9 -feet tall. The hoist foundation consists of six 5.5'X 5.5' 16" thick spread footings with 4 -foot tall 18 -inch diameter piers. The head frame has a 20 -foot square base, is 3 -feet by 12 -feet at the top and is 27 -feet tall. The head frame will be bolted to the existing shaft collar. The emergency escape system has been removed. Filter Building A pre- engineered metal building designed to house a filter system to clear the water obtained from the Deer Trail Ditch. The filter building is adjacent to the pump house which is located along the Deer Trail Ditch. The building is approximately 40 feet by 16 feet with an 8 -foot eave height. Concrete Drop Inlet Structure A concrete box inlet structure will be constructed at the intersection of Ditch C -24 and Culvert C -12. The box structure will be constructed out of a total of 44 cinder blocks. MR -156 2.05-21- 07/14