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Mr. Edwin Olivares <br /> February 8,2018 <br /> Page 2 <br /> was encountered. Water was encountered in the Fort Hays at approximately 36.5 feet BGS. On September <br /> 6,drilling extended to a depth of 49 feet. Essentially no cuttings returned to surface after drilling to a depth <br /> of 39 feet. The hard drilling and presence of water resulted in the rock being pulverized and converted to <br /> mud lodged onto the outside of the augers and not lifted out of the borehole. <br /> Returning on September 7,the cuttings had settled and the bottom of the borehole was tagged at <br /> approximately 44 feet BGS. The water level was measured at 29.5 feet BGS. Drilling proceeded to 56.5 feet <br /> (with essentially no returns)where a soft lens was encountered followed by very hard drilling just above 57 <br /> feet BGS. Drilling terminated at 57 feet BGS and the augers were pulled,and cuttings on the bit indicated <br /> the top of Codell Sandstone. An initial attempt was made to install a Fort Hays Limestone well,but the mud <br /> in the hole was heated by drilling friction to the point that it melted the PVC casing. Due to this and the <br /> presence of thick mud in the hole it was decided to abandon the borehole and return with an air rotary <br /> drilling rig to achieve a cleaner well completion in the same stratigraphic interval. Six bags of 10/20 silica <br /> sand were placed in the hole prior to covering the borehole with secured plywood for later plugging and <br /> abandonment. <br /> SITE DRILLING AND WELL CONSTRUCTION ACTIVITIES: DECEMBER 2017 <br /> On December 4,2017 CCG returned with Dakota Drilling, Inc.and a CME-75 drilling rig to plug and <br /> abandon the prior borehole in accordance with Colorado Division of Water Resources well construction rules <br /> (2 CCR 402-2),and proceed with drilling and well installation. A Notice of Intent for a second monitoring <br /> well was filed by GCC. <br /> Borehole abandonment <br /> The original auger borehole depth was tagged at 29 feet BGS. The hole was filled with 10/20 silica sand to a <br /> depth of 25.25 feet BGS,following by Portland cement grout to a depth of 3 feet below BGS. Local soils <br /> and drill cuttings were used to backfill the hole to ground surface. The ground surface was then graded with <br /> cover material to blend with the surrounding area and allow establishment of vegetation. The Colorado <br /> Division of Water Resources confirmed that GCC should treat this hole as a failed attempt with no plugging <br /> and abandonment report required. <br /> Borehole Drilling and Well Construction:MW-6 <br /> Given what was discovered during the September drilling,and anticipating the same conditions nearby in the <br /> Fort Hays,the plan was to complete a Fort Hays well and then step off and drill to the base of the Codell <br /> Sandstone and install a well screened only in the Codell. The drill rig was positioned 25 feet SW of the <br /> original borehole(along the same orientation as the fault mapped in the second mine panel). <br /> With stratigraphic contacts well-defined from the previous drilling,borehole drilling and installation of <br /> monitor wells was completed with procedures to minimize the disturbance of geologic materials,and <br /> minimize the introduction of fluids or other materials to the geologic formations. Hollow-stem augers were <br /> used to drill to competent rock,and air rotary was employed to complete the drilling,with cuttings samples <br /> collected along the way for lithologic descriptions. Therefore,the auger drilling extended several feet into <br /> the Smoky Hill(to a depth of 14 feet). Drilling was advanced from there to the base of the Fort Hays by air <br /> rotary,with contacts judged to be at approximately the same depths as in the original borehole;however,no <br /> water was encountered during drilling and no water was noted to enter the borehole after allowing to it sit for <br /> 45 minutes. <br /> Close Consulting Group LLC <br />