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Results of these analyses are provided in Appendix C. <br />VIII. MOFFAT STABILITY MONITORING WELLS <br />Six wells were installed in the Moffat area to monitor ground water levels. A <br />complete discussion of the purpose of the wells is provided in Section 4.6.9 of the <br />permit document. Elevations of the water in the Moffat wells are shown in Figure 36 <br />with the data provided in Appendix D. The 215 and 21B series wells have generally <br />been dry since 1990 while the 892 well series have been dry since their <br />installation. The stratigraphy into which these wells were completed is believed to <br />have been intersected during the construction of the Moffat sediment pond during the <br />fall of 1989. Consequently, these formations have been able to drain fairly freely. <br />Due to the draining nature of the formations, it is not anticipated that significant <br />potentiometric surfaces will develop in the future. <br /> During 1996 and 1997, all of these wells marginally responded to the wet <br /> spring conditions. A review of the data appears to confirm the continued integrity <br /> of the aquiclude between the Wadge seam and Lower Wadge unit and the lack of pore <br /> water pressure development i n the lower unit. <br />IX. MOFFAT STABILITY MONUMENTS <br />A system of three control points and six monuments were established in <br />the final Moffat pit area during the fourth quarter of 1997. The purpose of the <br />monuments are to monitor the hillslope for long-term stability. The three control <br />points were placed to form a large triangle. The reference control point was <br /> established along the top of the hillside in undisturbed ground above the final <br /> Moffat pit. The two additional control points (back-sites) were established in <br /> undisturbed ground northwest and south of the reference point. The back-sites were <br /> established to verify the location of the reference point. The monuments were <br /> installed in pairs with the first pair, SM-1 and SM-2, establish ed in the lower <br /> third of the final pit area. SM-1 was placed approximately 130 feet south of the <br /> final pit highwall and SM-2 was placed approximately 390 feet so uth of the final pit <br /> highwall. The second pair, SM-3 and SM-9, were installed approx imately mid-way <br /> along the pit. SM-3 was placed approximately 110 feet south of the highwall and SM- <br /> 9 was placed approximately 325 feet south of the highwall. The last pair, SM-5 and <br /> SM-6 were installed in the upper third of final pit area. SM-5 was placed <br />49 <br />