Laserfiche WebLink
David Berry <br />November 11, 2014 <br />Page 3 <br />result of the dewatered condition of the mine and the removal of a portion of the <br />overlying confining layer. <br />• Although the coal seam has been mined and temporarily dewatered, the coal seam <br />at the location of the MW -NW well is still under the influence of a pressure head <br />from ground water within the surrounding rock formations. It is this pressure <br />head and regional pressure gradient that is causing the refilling of the mine. If the <br />mine were not under the influence of a pressure head or pressure gradient, the <br />mine would never refill. <br />• The pressure head causing the refiling of the mine is evidenced by the <br />neighboring wells that exhibit water level elevations higher than the dewatered <br />mine areas. <br />• The removal of the coal material, the creation of a rubble zone in portions of the <br />mine and the temporary dewatered condition in the mine does not restrict water <br />levels in the mine at the location of the MW -NW well from recovering to levels <br />consistent with pre- mining conditions (above the top of the coal seam). <br />• Based on repeated testing of the MW -NW well, it is clear that the well is still in <br />connection with the mine workings so there is no reason to believe that the <br />condition of the well would restrict potential future water levels. <br />• The area of increased permeability associated with the mine excavation and <br />rubble zone will only impact the slope of the water table within and adjacent to <br />the location of the mine. Otherwise, the increased permeability of the mine <br />working will not impact water levels in the MW -NW well. <br />If you have any questions, need any additional information or would like to discuss these <br />concepts further, please do not hesitate to contact me. <br />Very truly yours, <br />BISHOP - BROGDEN ASSOCIATES, INC. <br />k.*a <br />Timothy A. Crawford, P.G. <br />Senior Project Manager/Hydrogeologist <br />TAC /jeb <br />Enclosures <br />2018.04 <br />www.bbawater.coni e Bishop- BrogdenAssociates, Inc. <br />