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Seasonal water Level changes have b~aen measured in the Vadge coal aquifer (see Table 7-3)- • There is no distinct trend concerning seasonal mean water levels. The shallowest mean water levels occur principally in the spring, but also occur in the summer and fall at four of the wells (2V, 4V, 13V, grid 18V). The dominant form of recharge appears to be snowmelt. Summer and fall rainfall appears to provide significant recharge [o some portions of the Vadge coal aquifer or there is a lag period before the response to spring recharge occurs at some wells. The deepest mean water levels appear to occur in the summer, fall, and winter. The amount of seasonal water level fluctuation also shows no trend. Four wells showed the least amount of water level fluctuation in the spring, three in the fall, and two each in the summer end winter (see Appendix 7-2). Five wells showed the greatest amount of eater level fluctuation in the fell, three in [he spring, and three in the summer. Minimal seasonal water level fluctuations range from 0.2 feet at Vell 14V to 13.4 feet at Vell 3V. The greatest seasonal fluctuations range from 0.3 feet at Well 14V to 47.7 fee[ at Well 15 V. Premining water level fluctuations in the Vadge coal aquifer are appreciable. Some of the fluctuation may be attributed to residual effects from water quality sampling. Vadge Underburden Water Levels. One well, CV-52V-3EI, is constructed in the Vadge underburden. Vell 3E1 was completed in 1980 and monitored for water levels through 1983. The location of the well can be found on Exhibit 7-1. Appendix 7-2A contains water level data collected at Vell 3E1, Vadge Coal Vells 3V, 4V, and 17V, and Volf Creek Coal Vells 3uC, 4uC, and 17uC. Early eater level data at Vell 3E1 (prior to December 1980) indicate the Vadge Underburden is not under confined conditions. Both the Vadge Coal above and the Volf Creek Coal below the Vadge Underburden are under confined conditions, as indicated by comparisons of simultaneously collected water level data presented in Appendix 7-2A for wells completed in both units. Table 7-4A presents select same-day measurements of water level elevations and artesian heads collected at Vadge Coal and Volf Creek monitoring wells. Artesian heads were determined by subtracting the top of coal elevation from the water level elevation at each monitoring well. In all cases, the Volf Creek Coat unit is under higher confining pressure than the Vadge Coal unit. This relationship is more pronounced in the vicinity of the II-V Mine as the units progress downdi p, as indicated at Vells 17V and 17VC, where the Wolf Creek Coal unit exhibits more than double the artesian head as the Vadge [oal unit. 16 Revised 02/11/94