2012-12-31_REVISION - C1981014 - Laserfiche WebLink

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energy fuels coal, inc. southfield mine • post office box 459 • florence, colorado 81226 • (719) 784 -6395 December 21, 2012 Ms. Janet Binns — Reclamation Specialist Colorado Division of Reclamation Mining & Safety 1313 Sherman St — Room 215 Denver, CO 80203 RE: Technical Revision No.40 (TR -40) - Southfield Monitor Well MW -NW Energy Fuels Coal, Inc. — Permit No. C -81 -014 — Southfield Mine Dear Janet Binns: L'1 RECEIVED DEC 3 1 2012 nixision of Reclamation, Mining & Safety EFCI is in receipt of the Division's letter of November 28, 2012 concerning the Southfield mine's monitor well MW -NW. However, we find discrepancies in the Division's calculations of measurements concerning MW -NW. The elevation of the floor of the mine workings (the entry) does not determine the bottom of the well MW -NW and it should not be assumed that the bottom of the well and the floor level coincides. MW -NW was formerly used as a dewatering well and as such, a sump, lower than the floor level is required to drain the entry floor. The elevation of the mine entry floor is determined by the Southfield Permanent Closure Map, Sheet land is also referenced in TR -35, Adequacy Comments (09- 26 -03) in Response #3. EFCI concurs with the Division's stated elevation of 5,855 ft elevation of the entry floor. The elevation of the ground surface at the collar of MW -NW is determined by the Southfield Reclamation Plan map, Map 33. Accuracy of the location of MW -NW on Map 33 is confirmed in TR -35, Response #4. MW -NW is also shown on the Southfield Hydrology Map, Map 12. Both maps depict the mean of the ground surface contours at MW -NW as being 6,232.5 ft elevation. To determine the elevation of the referenced partial obstruction in the well, it is best measured from the top of the steel casing of MW -NW. It should be noted that the Division's remote camera, although very close to the partial obstruction, the camera was viewing from above the obstruction (not in contact with it). Conversely, Kent Gorham, former hydrologist with the DRMS during his inspection of MW -NW on April 17, 2012, measured 354 ft from the top of the well casing to the partial obstruction using a homogenous line probe. The well casing protrudes 1.2 ft above the surface ground level (6,233.7 elevation). Subtracting Kent Gorham's measurement of 354 ft from the elevation of the top of well casing determines the elevation of the partial obstruction to be 5,879.7 ft. EFCI concurs that the coal seam was 5.5 ft thick in the mine workings at MW -NW (typical height of mine roof was 6 ft) and concurs that the elevation of the mine roof is 5860.5 ft (or higher). These values determine a difference of 19.2 vertical ft between the mine roof and the top of the partial obstruction in MW -NW. The water test dumping 1500 gallons of water in MW -NW (4 -17 -2012) estimated a flow rate of more than 140 gallons per minute (GPM) into the well (see EFCI letter of June 8, 2012). The 4 -17 -2012