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Whirlwind Mine Groundwater Characterization Report <br /> electric submersible pump (ESP)that is energized by a nearby powerline and transformer. The <br /> well is completed at a depth of 150 ft bgs, with the main groundwater source interval located <br /> between 100 and 115 ft bgs. The static depth to water reported by the drilling reports is 75 ft <br /> bgs. According to EFR (2008), a "smaller aquifer is located at five-foot thick limestone bed at 75 <br /> to 80 ft bgs. The approximate elevation of the well is 7,444.74 ft AMSL, which puts the <br /> approximate groundwater level at 7,369.74 ft AMSL. The well was sampled by EFR in April <br /> 2007, after pumping the well at a rate of 12.5 gpm for 30 minutes. <br /> Cherokee Wells <br /> Two historical wells were located near the Cherokee Shaft, approximately 2,000 ft east to <br /> southeast of the Whirlwind portal. The wells, one shallow and one deep, are at elevations of <br /> approximately 7,190.5 and 7,179.7 ft AMSL, respectively. The shallow well is approximately <br /> 40 ft deep and is uncased. The deep well is cased to a depth of 110 ft. The BLM sampled the <br /> shallow well in 1999 and recorded a static depth to water of 37 ft bgs (elevation of 7,153.5 ft <br /> bgs). The deep well was sampled in 2000 with a static depth to water of 77 ft bgs (elevation of <br /> 7,102.7) (ERF, 2008). <br /> 4.2.1.9 Spring Discharge <br /> Two springs, DP Spring and PR Spring, have been monitored by EFR for discharge and water <br /> quality since March 2008. Discharge data are collected on a quarterly basis. Tables 4 and 5 <br /> show the results of the discharge and field parameter measurements. Figure 7 shows spring <br /> discharge for the two springs plotted against time from 2008 to 2021 and annual precipitation at <br /> the Gateway 1 ENE (Station ID USC00053246) weather station from 1990 to 2021. <br /> Figure 7 indicates a distinct decreasing trend in discharge at both springs since measurements <br /> began in 2008. This decreasing trend is more obvious in PR Spring up until October 2016. After <br /> that, discharge from the spring increases dramatically, and then begins another general <br /> fluctuating decreasing trend into 2021. Field notes indicate that the discharge pipe at PR Spring <br /> was becoming plugged with roots in March and June 2017 and these roots were cleaned out in <br /> September, 2017 when a much greater flow rate was recorded. It may be the case that gradual <br /> plugging of the discharge pipe occurred from 2009 to 2017. <br /> Western Water& Land, Inc. 23 <br />