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George V. Patterson, Energy Fuels Coal, Inc. <br />Page 2 <br />July 1, 2015 <br />Rule 4.18 –Protection of Fish, Wildlife,and Related Environmental Values <br />The rulerequires that an operator must, to the extent possible, prevent, control, and suppress coal <br />fires. Therisk of fire has not yet been well characterized. <br />Please attempt to measure theconcentrationof methane within the mine workings. <br />1. <br />This couldbe achievedby pumping air out of MWNW and sampling the air <br />withdrawn from the cavity. <br />Please reconsider the location for MWNW-2. The Division feels that the <br />2. <br />replacement hole should be drilled as close to the location of MWNW as possible, <br />and in the 1-North section,since:(i) more inflow data is available at this point than <br />at any other;(ii) it is located at a local sump within the workings, and as such <br />stands a better chance of locating a pool of water; (iii) previous modeling work done <br />by Bishop Brogden and Associates was done at this location; and most importantly <br />(iv) the atmosphere within this part of the mine can be well characterized by <br />sampling directly from the casing of MWNW. <br />3. <br />Coal fires have been documented in the immediate vicinity of the Southfield mine, <br />possibly associated with the Double Dick mine, which operated in the Vermejo and <br />Brookside seams, and with the Black Diamondstrip mine(Renner,2005).The Inactive <br />Mines Program routinely drill into active mine fires and do not view it as an especially <br />hazardousactivity, since the fire tends to consumeany availablemethane.The biggest <br />riskis consideredto bethe venting of combustion gases to the drilling crew, so a multi <br />gas meter should besitedat the driller’s station. The meter will alarm if any of the gas <br />constituents becomes a health andsafety issuewhich will allowthe area to be evacuated <br />until the atmosphere reaches safe levels. <br />Casingis setas soon as is practicable; generally within an hour or two of completing the <br />hole. Aninternallythreaded steel casing is used;open at whatever interval is required <br />within the mine void. Apacker is set just above the mine void and the annulus is grouted <br />in place to just below ground surface, in the manner proposed by Young Drilling <br />Company. <br />Please survey the area for recent evidence of underground fires. <br />4.The explosive range of methane is known to be5-15%under normal temperature and <br />pressure conditions (Zabetakis, 1965).Ifthe results of sampling determine that methane <br />is present within its explosive rangeprecautionsmust be takento ensure that the drilling <br />does not cause a spark, or even excessive heat as the bit / drill stem enter the mine void. <br />The Inactive Mines Program within the Division has considerable experience of this type <br />of work and is of the opinion that it is relatively straightforward for a competent drilling <br />contractor. <br />