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(Tab )3, Facilities). Seneca anticipates encountering artesian conditions at the proposed • <br />Toast production well site similar to the Seneca II-V production well. <br />Potentiometric Surfaces. Potentiometric surface contour maps for the alluvium, Vadge <br />overburden, Vadge coal, and Vadge underburden ere presented on Exhibits 7.2 through 7-4. <br />The water table surfaces for the alluvium along Sege end Grassy Creeks ere shown on <br />Exhibit 7-2. The water table elevations used on the exhibit are [he arithmetic mean of <br />valid levels obtained (see Table 7-3). Voter level date used to construct the surfaces <br />are contained in Appendix 7.2. Several of the water table surface contours along Sage <br />Creek were connected to the Yadge overburden potentiometric surface contours, es it is <br />suspected that ground water in the Yadge overburden influences alluvial ground water along <br />Sage Creek. Flow gradients were calculated by dividing the difference between water <br />surface elevations at two wells by the channel distance between the wells. <br />The overall water table gradient along Sege Creek between YSAL12 end YSAL) is .024 ft/ft. <br />Gradients along Sage Creek range from .020 ft/ft doungradient of the Yoest permit boundary <br />(YSAL4 to TSAL1) up to .027 ft/ft between sl luvial Yells YSAL6 and YSAL4 (see Exhibit • <br />7-i). Flow direction in the Sage Creek alluvium is to the north, essentially paralleling <br />the drainage direction. In the Grassy Creek alluvium, water table gradients ere similar, <br />ranging from .022 ft/ft along the 'main Chanel upstream of Vell YGAL15 (Exhibit 7-t) to <br />.024 ft/ft between YGAL16 downgredient to the main Grassy Creek channel. Flow direction <br />in the Grassy Creek alluvium is to the northeast. Although only one alluvial well <br />monitors the water table in Annand Draw, the gradient in this reach likely mimicks the <br />proximate stream channel gradient of .080 ft/ft. <br />The potentiometric surface for the Vadge overburden is also shown on Exhibit 7-2. The <br />potentiometric surface for the overburden was constructed using the arithmetic mean of <br />valid water levels collected during the baseline period (see Table 7-3). Appendix 7-2 <br />presents water level date collected at each Yadge overburden well. Ground water in the <br />overburden occurs under both confined and unconfined conditions. Overburden near the <br />Vadge coal outcrop is dry or unsaturated. Saturated thicknesses end confining conditions <br />increase in the direction of dip. <br />Saturated thicknesses in the eastern portion of the Yoest mining area (east of the Fish <br />Creek anticline - five-year mining block) varies from just above 10 feet (YOV2) up to 200 <br />feet et YOV28. Overburden flow gradients in this area range from .150 ft/ft towards the <br />22 Revised 03/07/95 <br />