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Mr. Leigh Simmons July 9, 2015 Page 2 <br />always a primary concern at any operating underground coal mining operation. The <br />Southfield Mine has been closed and sealed for over 13 1/2 years. EFCI has no way of <br />knowing the location and/or levels of methane that may be present in the sealed mine <br />workings. Furthermore, after careful consideration, EFCI chose not to conduct field <br />methane testing at MW -NW for a variety of reasons, including the additional time and <br />expense considerations. EFCI does not believe that the presence or absence of methane <br />in the existing well casing of MW -NW should be used as positive evidence of methane <br />�\ conditions elsewhere in the workings. For example, roof fall, blockages, flooding, seals <br />between mine entries, or other unknown conditions between different areas of the mine <br />could result in pockets of explosive methane levels, while other areas of the mine <br />workings may be mostly methane free. Given the circumstances and the unknown <br />conditions underground, the only reasonable and safe assumption must be that methane <br />may be present and the appropriate measures must be taken accordingly. Even if <br />methane were not measured at MW -NW, no drilling contractor would take that <br />information to mean that the sealed mine workings were methane free everywhere within <br />the sealed mine. <br />2. DRMS concern <br />Please reconsider the location for NIWNW-2. The Division feels that the replacement <br />hole should be drilled as close to the location of MWNW as possible, and in the 1 - <br />North section, since: (i) more inflow data is available at this point than at any other; <br />(ii) it is located at a local sump within the workings, and as such stands a better <br />chance of locating a pool of water; (iii) previous modeling work done by Bishop <br />Brogden and Associates was done at this location; and most importantly (iv) the <br />atmosphere within this part of the mine can be well characterized by sampling <br />directly from the casing of MW -NW. <br />EFCI response <br />EFCI previously addressed the reason for the relocated site proposed in TR -46 in the Risk <br />Evaluation that was submitted to the Division (via email 6/12/2015 10:41 am). This <br />information was in response to questions raised by the DRMS on May 27, 2015 in a <br />meeting with Gorham Energy Consultants, acting on behalf of EFCI. Please review this <br />information. EFCI has explained many times previously that the location of MW -NW <br />was chosen opportunistically because it was an existing "conduit" into the mine workings <br />that could be easily probed to possibly detect water as the workings flood and with <br />multiple readings over time, estimate the rate of flooding that would occur following <br />mine closure. It was not chosen for its outstanding attributes as an ideal location to return <br />detailed information about mine flooding and mine water quality. This fact is well <br />documented in the written record. EFCI has also explained many times that roof <br />conditions in the workings in the proximity of MW -NW were known to be very poor and <br />