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Final Technical Report, 2014 Monitoring Well Rehabilitation Program Bowie Mine 7 <br />2.2 Well P- TC -03 -02 <br />A video inspection of well P- TC -03 -02 (upper B- Sandstone), completed on July 22, 2014, <br />showed that the well was blocked by clayey debris at a depth of 540 feet btoc. Rehabilitation <br />work on this well began on August 8, 2014. RACS moved the workover rig to site and dropped <br />a water jetting tool attached to a tremie pipe into the hole. The jetting tool and bottom 16 feet of <br />tremie pipe were immediately clogged with soft gray clayey debris. A downhole measurement <br />using a tag line confirmed that the clay debris began at a depth of 540 feet. The jetting tool was <br />repaired and again dropped downhole and jetting began at 507 feet. The hole was successfully <br />cleaned to a depth of 573.7 feet at which point the tremie rods were unable to descend further. <br />Video inspection of the hole showed a slender white deposit with a suspected rock on top of it <br />bridging the well bore at this depth. Using a compressor, the airlift technique was used to remove <br />the suspected rock and attempt to clean away the white calcium deposit. Subsequent video <br />inspection showed that the rock was removed, but the calcium deposit remained in the well <br />casing. At this point, a stiff nylon bristle brush cleaning tool was dropped downhole to try and <br />scrub away the obstruction. The brush tool unfortunately sheared off at the point of attachment <br />with the tremie pipe and was stuck in the hole. One more attempt was made to jet clean the <br />obstruction followed by airlifting of the hole. A downhole video showed that the hole was dry to <br />573.7 feet, but the white deposit remained on the casing wall preventing further ingress to the <br />borehole and the brush was stuck in the casing below the calcium deposit. On August 9, 2014, <br />work on monitoring well P- TC -03 -02 was temporarily suspended. <br />On September 15, 2014, RACS moved a drilling rig with tools capable of fishing out the brush <br />lost in the well. After successful removal of the nylon brush tool, the drillers were able to grind <br />through the calcium deposit and tag the bottom of the hole at 587 feet using a water jet tool <br />attached to the tremie pipe. On September 16, the well was jetted from a depth of 575 feet, just <br />above the screened interval to avoid packing sediment into the screen. The surface return water <br />quickly showed abundant coarse grained sand. The sand appeared to be 8 -12 sand pack used for <br />the well construction. On September 19, 2014 a bailer was used to measure water quality from <br />the well which showed an average pH of 12.57 s.u., conductivity of 7.43 gS /cm, and temperature <br />of 22.8° C. Rehabilitation efforts were suspended on September 19, 2014 since the well screen <br />was apparently breached and the sand pack was filling the screened interval, rendering the well <br />dysfunctional for collecting water quality data; however, the well could be used as a piezometer <br />to measure groundwater level. The well completion diagram is presented in Appendix A. <br />November 2014 HydroGeo, Inc. <br />