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~cr-•o-i»~ 1G "~tl nh~_lr+la LMWSUrv <br />Page Eight <br />Mr. Norm Every <br />Mountain Coat Company <br />tlbl ,Jb.) 4410 r Vv <br />Harding Wwson Associate <br />Both full mitigation alternatives (affecting the entire slide mass) and partial mitigation <br />alternatives (affecting only a portion of the slide mass) were considered. <br />Results of the evaluation will be found in Table 4.0. <br />5.0 Recommcudations <br />Based on Table 4.0, HLA trcommrnds that MCC seriously look at the option of <br />dewatering the hedrock behind the sfide using a combination of horizontal and vertical <br />wells and look at possibly depressurising the cobble zone near the toe of the slide with <br />horizontal wells. This would both attack the source of the slide and relieve the pressure <br />that occurs in the cobble zone under the slide in the spring. if MCC wishes to proceed <br />with this option/options then a set of plans could be developed showing drill layouts for <br />this option and a contractor could be obtained and get started and get completed this Fall. <br />Also a tieback system utilizing both extending the existing buttress to the west to protect <br />the existing stack tubes and a possible tieback system to the east of'the buttress should be <br />designed as a optional item to WEM as they have proved to be very effective and can act <br />as a fallback if dewatering did not stop this landslide. If you have any questions, please <br />give me a call. <br />Sincerely, <br />HARDING LAWSO ASSOCIATES <br />Chazles C. Rehn, P.E. <br />Salt Lake City Principal Engince_ <br />~M <br />Ken Myers, P.E. <br />Mines Group, Reno, Nevada <br />Enclosure <br />