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<br />Wolf Creek/Wadge Interburden <br />Peabody installed one well to monitor the Interburden within the permit area. <br />The Interburden consists of 165 feet to 215 feet of interbedded sandstone, <br />shale, siltstone and coal, thus forming a relatively impermeable zone between <br />the underlying Wolf Creek coal and the overlying Wadge coal. <br />T+bnitoring data for the well was presented in the permit application, Depth <br />to water measurements at this well were made for about 22 months. This data <br />not only shows very little seasonal fluctuation, but that the Interburden at <br />this site is under unconfined or water table conditions. This is not a <br />logical characteristic because both the Wolf Creek coal and the Wadge coal, at <br />least seasonally, exhibit artesian head at this site. It is possible that <br />this well has not been properly completed, or that a perched aquifer was <br />intercepted by the well. Based on analysis of the Wolf Creek and Wadge coal, <br />it seems iogica7 to assume that water within the Interburden, as in the other <br />units, will exhibit confined conditions oowndip of the Sage Creek anticlinal <br />axis. <br />No water quality sampling has been done in the Interburden, <br />Wadge Coal <br />The Wadge coal is the principal seam of interest at the Seneca II-W Mine. It <br />is typically 11 to 13 feet thick, except where split by partings. <br />The Wadge coal outcrops to the east of the permit area. These outcrops and <br />perhaps a portion of the overburden east of the permit area, are thought to be <br />the major source of recharge to the Wadge. <br />Depth to water and water quality are monitored at five sites within and <br />adjacent to the permit area. <br />The varying amounts of head measured at these wells again indicates that the <br />major component of flow is to the west. <br />The amount of head within the Wadge, as in all the units in this area, is a <br />function of distance from the recharge area (anticlinal axis) and the type of <br />over/underbur den present. <br />The Wadge coal is found in a confined state in most of the wells which have <br />been monitored. At well GW-42-S2W-5W, a downdip well due west of the south <br />pit area the Wadge appears to be semi-confined. While pumping this well, <br />drawdown was observed in an adjacent overburden completion well. This <br />observation indicates that there is, at least in this location, a hydrologic <br />connection between the Wadge and the overburden, assuming the wells were <br />properly completed. <br />Aquifer tests were performed at two wells. One well failed during the test. <br />The transmissivity calculated at the other well was 0.03 FT2 per day, while <br />storativity has been estimated to be on the order of 1 X 10-4. <br />- 14 - <br />