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George Patterson <br />July 19, 2013 <br />Page 2 <br />On March 20, 2012, in response to a citizen's complaint, EFCI lowered a wooden block into the <br />MW -NW well to determine the depth of the well. This investigation indicated that the well was <br />obstructed above the roof of the mine workings at an elevation of approximately 5879.7 feet. An <br />April 17, 2012 investigation in which a total of 1,500 gallons of water were introduced to the well <br />confirmed that, although obstructed, the well was still in connection with the mine workings. The <br />obstruction and lack of corrective action on the part of EFCI has resulted in a Notice of Violation <br />from the DRMS. As described below, we believe the MW -NW well or another monitoring well at <br />that location is not necessary to provide data for the monitoring program. <br />Mine Refilling <br />Dewatering of the Southfield Mine was accomplished during operations by pumping water to the <br />surface. Dewatering records, attached for reference, from 1994 through 2000 were provided by <br />EFCI and reviewed to understand potential mine inflows. In 1994, EFCI terminated pumping to the <br />surface and began pumping inflows to the lower portions of the mine workings where mining had <br />terminated. All pumping within the mine ceased in 2000. Based on the dewatering records provided <br />by EFCI approximately 241.6 acre -feet were observed inflowing into the mine works or were <br />pumped within the mine to the lower portions of the mine between 1994 and 2000. Of this volume, <br />9.8 acre feet were pumped into the 1 North Sub -Mains area with the remainder of the volume <br />accumulating to the West Mains area either by pumping or by gravity. Mine inflow was monitored <br />up to September 2001 when the mine was permanently sealed. In 2001, mine inflow was reported as <br />only 5.1 acre -feet. Inflow records for the mine do not include inflow information for the 1 North or <br />2 North areas for 1998, 1999 or 2000 and previous records are misleading because these areas were <br />used intermittently as reservoirs and pumping from these areas included pumping of stored water. <br />Based on observations by EFCI personnel, inflow to the 1 North and 2 North areas is estimated to be <br />approximately 14 acre -feet per year. Inflow records were also not reported separately for the mine <br />in 1996 due to that fact that the mine did not operate due to lack of sales contracts. <br />As detailed below, based on the actual observed inflow rates, actual mine inflow to the mine is much <br />lower than originally estimated. This most likely resulted from the dewatering of coal seams, <br />fractures and neighboring mine working that occurred during mining which reduced post mining <br />inflows in comparison to dewatering rates during operation. Actual mine inflows observed between <br />1998 and 2001, after mining was completed and before the mine was sealed, averaged approximately <br />10.1 acre -feet per year (af /yr). This inflow rate is representative of the mine workings separate from <br />the North mine areas. With the addition of the estimated 1 North and 2 North area inflow rate of 14 <br />acre -feet per year, the total estimated mine inflow rate is approximately 24.1 acre -feet per year. <br />Based on a calculation presented on page 2.05.6 -32 of the plan document, the total mine workings <br />volume is 5,700 acre -feet. This is a conservative volume for the purpose of determining the timing <br />of refilling because the volume does not include any neighboring mine workings that were also <br />dewatered during mining that will now also refill along with the Southfield Mine workings. Based <br />on a previous estimate of mine inflow of 20 of /yr presented in TR -35 for the Southfield Mine, it was <br />