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Lyster Pit Hydrology Summary <br /> The Lyster Pit was permitted in 2008. During the April 10, 2008 pre-op inspection conducted by <br /> Travis Marshall (DRMS),the site had naturally"swampy" conditions including the presence of <br /> standing water, as seen in the Division site inspection photographs (Figure 1). Historical aerial <br /> photos available through Google Earth also show the standing water condition on the Lyster site <br /> and neighboring properties back in 2004 (Figure 2). The Lyster Pit was operated by Connell <br /> Resources prior to its current operator United Companies. Connell personnel informed GLA that <br /> in 2012 and 2013 there were times that the dewatering pump was not operating and standing <br /> water conditions were experienced during both pumping and non-pumping time periods. <br /> Piezometer data gathered from four groundwater monitoring wells onsite over many years, going <br /> back at least to 2016, shows that the natural groundwater table is close to the surface (Figure 3). <br /> This includes periods of time when the dewatering pump is running. GW-3 and GW-4 (northeast <br /> corner of the permit area) both show groundwater levels very near the surface(Map 1 —NW <br /> Corner). GW-2, which was abandoned in 2010, shows groundwater levels very near the surface <br /> as well (Figure 3). GW-2 was located east of the Lyster Pit on the Ocker Property. <br /> Adjusting for piezometer casing height,the ground water elevation in the northeast corner of the <br /> permit area, adjacent to Mr. Ocker property, is within a foot of the surface (Appendix 1). This <br /> includes during periods when the dewatering pump is running. In fact,the recharge flow from <br /> the east of the site clearly prevents the dewatering activities to the west of GW-3 and GW-4 from <br /> having a significant effect on the groundwater level. This can be seen in Appendix 2— <br /> Groundwater Data which shows the depth to water measured by each piezometer along with if <br /> the dewatering pump was either running or not running. GW-3,the furthest north and closest to <br /> CO-394 groundwater monitoring well, shows water levels within two to three feet of the top of <br /> the casing. Accounting for casing height of roughly a foot,this leads to a groundwater table <br /> typically within 12 inches of the ground. GW-4 frequently measures a groundwater level above <br /> the local topography. Such a close groundwater table will not facilitate substantial surface water <br /> infiltration. <br /> The groundwater lake at the Lyster Pit had an elevation of 6180.6' when surveyed in November <br /> 2020. This is over ten feet below the ground level at GW-3 (6192.0') and GW-4 (6192.0'). <br /> Lyster Pit NOV <br /> November 2020 3 t;n Lcwicki and Associates Nl,l.t <br />