Laserfiche WebLink
35 <br /> <br />coal and overburden aquifers. <br />E. Summary of Existing Situation <br />Based on our analysis we have concluded that the overburden waters <br />in the project site are unconfined except in the vicinity of well 111 <br />where the overburden aquifer is locally confined. F1e are fairly confident <br />that the coal seam is indeed a confined aquifer. The fact that the <br />piezometric head in the overburden is greater than in the coal suggest <br />that there would be a tendency for water to move from the overburden <br />into the coal if sufficient permeability existed. Evidence that such is <br />not the case is provided by a_ comparison of the water quality in the <br />two.zones. The dissolved solids concentration in the overburden water <br />is greater than in the coal waters by a factor of 2 or more. If there <br />were significant hydraulic communication between the two aquifers the <br />dissolved solids content of the two waters should not show such a dis- <br />parity. <br />Groundwater discharge through the coal seam was about 0.1 acre foot <br />per year, This discharge is so small that it can be neglected for all <br />practical purposes. Flow from the overburden to Ennis Draw was estime~ed <br />at approximately 5.4 acre feet per year. <br />It is not possible to calculate the actual flow from the south <br />through Ennis Draw based upon data presently available to us. However, <br />we do believe that the discharge through the draw from the south is <br />significantly greater than the lateral inflow contributions from the over- <br />burden in the study area. Evidence that such is the case is provided by <br />a comparison of the water quality in the overburden and Ennis Draw. The <br />fact that the overburden waters, with a dissolved solids concentration <br />of 7025 ppm, discharge into the draw suggests that the much lower dissolved <br />Y <br />