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PHILLIPS MINING, GEOTECHNICAL 8 GROUTING, INC. <br />Following the closure of the mine, it has been decided to plug the 9360 Level Adit. The <br />plug will be constructed to significantly reduce, or essentially eliminate, the flow from the <br />9360 Level Portal. The plug will be located approximately 135 ft. into the adit from the <br />portal, i.e., just downstream of the zone that is dripping, that is closest to the portal. The <br />ground cover to surface at this location is approximately 54 ft. <br />The ground conditions at the plug location are poor. Recently, several hundred feet of <br />adit upstream of the portal, including the proposed plug location, have been rehabilitated <br />in order to gain access and gather information regarding the source of the water into the <br />adit. During this rehabilitation, some of the timber sets, originally placed on 4 ft. centers, <br />with tight lagging, have been supplemented by additional sets, as required, so that in <br />places, the set spacing is as close as 2 feet. <br />The silty-clayey matrix of the ground azound the proposed plug site suggests that the <br />overall permeability of this material should be relatively low. Seepage passed the new <br />plug should therefore be low if good contact is achieved between the plug and the <br />surrounding ground. Any seepage that does occur is likely to be associated with the <br />plug/gound contact or with any frachues that maybe present. These fractures are either <br />inherent in the rock or have opened by relaxation of stresses after excavation. Blasting <br />was not performed during the excavation of this section and so this will not have <br />contributed to the fracturing. Any fractures that exist, together with the potential gap at <br />the rock/concrete contact, will provide channels for leakage of water passed the plug. A <br />grouting program will have to be performed around the plug to seal these leakage paths. <br />The natural phreatic level that existed in the ground prior to mining is not known. <br />However, it was reported that the 9360 Level and the level below, the 9200, were <br />essentially dry when they were originally excavated. This indicates that these mining <br />levels were probably above the phreatic level. Upstream of the plug, a raise connects the <br />Page 2 <br />