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George Patterson <br />July 19, 2013 <br />Page 4 <br />North area of the mine is hydrogeologically connected. <br />Conceptual Model No. 3 — The seals in the 1 North, 2 North and 3 North areas do not restrict water <br />flow and allow for localized hydrogeologic connection, but, due to the mine layout these areas are <br />separated from the rest of the mine and the North areas refill as a single unit. <br />This conceptual model assumes that the entire North area of the mine is hydrogeologically <br />connected with itself, but is disconnected from the rest of the mine workings. This conceptual <br />model is supported by the lack of a water level in the MW -NW well which would be expected if <br />some level of hydrogeologic connection did not exist. This conceptual model assumes that due to <br />the layout of the mine and specifically the isolation of the North area of the mine, the North area <br />refills as a single unit. <br />Based on the closure map, there is approximately 1,494 acre -feet of mine volume in the 1 North, 2 <br />North and 3 North areas that is below the MW -NW monitoring elevation of 5860.5 feet. Based on <br />the North area inflow rate of approximately 14 acre -feet per year, water would not reach the <br />monitoring elevation of the MW -NW well for approximately 106 years or until the year 2106. <br />Refilling Conclusions <br />Due to the fact that it is apparent that the 1 North, 1 '/z North and 2 North areas confined by the mine <br />seals is in fact in connection with some portion of the rest of the mine, water is not expected to reach <br />the monitoring elevation of the MW -NW for between 106 to 120 years, or between the years 2106 <br />and 2120. <br />Existing Monitoring wells MW -23 and MW -65 <br />The MW -65 well is completed in the Dirty Jack o' Lantern coal seam down gradient from the mine <br />workings and MW -23 is completed in the Red Arrow coal seam up gradient from the mine <br />workings. The mine workings targeted coal from both the Dirty Jack o' Lantern and Red Arrow coal <br />seams which are now hydrogeologically connected locally by the mine workings. Accordingly, <br />local to the mine workings, the seams will act as a single hydrogeologic unit. MW -23 and MW -65 <br />are, therefore, completed at intervals that are in hydrogeologic connection with the mine workings <br />and the monitoring of water quality from the two wells will provide information regarding changes <br />in water quality resulting from the mining operation. Both wells are currently saturated and samples <br />can be collected and analyzed for the purpose of the monitoring program. <br />Water level measurements collected from the MW -23 and MW -65 will also provide information <br />regarding water level changes in the seams resulting from the dewatering of the mine. As presented <br />in the Southfield Mine 2012 Annual Hydrologic Report and attached as Figure 2 and 3 from that <br />report, water levels in both monitoring wells dropped by approximately 70 and 40 feet, respectively, <br />when mining and dewatering activities began indicating that the wells are hydrogeologically <br />