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• as along the western flank. The northern-most fault occuring on <br />the nose of the anticline apparently dies to the north (where it <br />subparallels the strike) and increases in displacement to the south <br />where it has a magnitude of at least 90 feet at the junction with <br />the lease boundary. <br />The groundwater recharge area for the sediments that will <br />be removed during mining occur up dip from the nose and the flanks <br />of the anticline and are exposed along the crest of the structure. <br />Since this area is topographically high in comparison to surrounding <br />terrain, and is not transected by perennial stream flow, all recharge <br />to the groundwater system must come from precipitation events. <br />water that enters the exposed sediments will migrate down dip <br />towards the deeper areas in the basin. This flow is expected to <br />be minimal, however, becasue of several mitigating factors. <br />First, the average annual precipitation is small (usually <br />around 11 inches per year) which is not conducive to large quantities <br />• of water entering the recharge area. Secondly, the topography of <br />the recharge area is sloping rather than flat lying which promotes <br />runoff during precipitation events and decreases the time for water <br />to be introduced into the outcrop area. Thirdly, the strata of <br />the Coalmont Formation are highly interbedded and lenticular in <br />nature which greatly retards any water entering the recharge area <br />as it migrates down dip. These lenticular relationships are <br />documented on the cross sections which are discussed in Section <br />2.04.6. <br />The general hydrologic properties within the Coalmont Formation <br />in the vicinity of the proposed permit area are basically simple. <br />The lenticular sandstones occuring in *_he section (essentially over- <br />lying the coal) act as thin aquifers and are restricted laterally <br />by facies changes as they intertongue with siltstone. The less <br />sandy siltstones and shaley siltstenes that are interbedded with the <br />sands act as aquicludes which restrict the vertical component as <br />• well as the lateral component of groundwater movement from the sand- <br />-57- <br />