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MCC is also complying with the second bullet listed (Field Monitoring) az evidenced by our weekly reports which <br />cover the entire project, rather than just specific areas of concern, az committed. It is this field monitoring that <br />revealed that the planned site for topsoil pile 143 was too steep and wet, and would have likely resulted in a failure, <br />so the pile was moved. Additionally, please recognize that these reports are burdensome to MCC. 1 would like to <br />explain this in person or over the phone at the next available opportunity. <br />The third bullet, addressing construction methodology, is admittedly the most difficult part of the construction <br />approach to execute in an efficient and proactive manner, however we do feel we are meeting our obligations in this <br />area az well. Although MCC haz not used benched slopes across the board, for a variety of reazons based on field <br />conditions, we have designed benched cut slopes in particular critical areas, such az the Shaft N3 cut slopes and the <br />lower Sylvester Gulch road. We have shifted road alignments to better match the topography, flattened design <br />slopes in numerous areaz, and installed more than 3,000 feet of extra french drain to date to control groundwater. <br />The fourth bullet of the listed program parts addresses Slope Failure Mitigation. There are a number of ways [o <br />mitigate slope failures, ranging from quick and easy, to time consuming and expensive. We believe that Dr. <br />Pendleton agrees with MCC, that except perhaps for the failed road section, none of the slope failures experienced <br />in Sylvester Gulch to date are catastrophic and global in nature. As such, immediate implementalion of extensive <br />mitigation were not and are not warranted. We believe it is prudent and reasonable to implement quick, site-specific <br />mitigation meazures in the short-term, monitor the performance, and implement additional measures az warranted <br />by the actual conditions. This is what was done at the subs[ation cutslope, for example, in designing and <br />constructing the mid-slope rock-lined ditch and french drain. <br />Pertaining to mitigation and monitoring, please recall [he buttress that MCC has built for the small failure south of <br />the intake shaft location, the supplemental monitoring (strain gauge piezometers) of the F-walls, and MCC's <br />continued efforts (through more than five design editions) to avoid extensive cuts at the Shaft k3 site. Well over <br />5300,000.00 has been spent on drilling, laboratory work and geotechnical consulting associated with this project. In <br />addition, MCC's civil engineer for the project, Eric Mende, P.E., spends much of his time on a weekly basis on <br />these issues alone. <br />MCC reaffirms iu commitment to do what is needed to ensure the long-term stability of these facilities. Contrary to <br />your perception that MCC is disregarding the advice of our consultants, our approach is based on a careful <br />consideration of a!! the information at our disposal. This includes analyses and evaluations by our consultants, az <br />well our own engineers' intimate experience with and knowledge of field conditions. Additionally, MCC <br />thoughtfully considers al! recommendations, including those of the Division. <br />Please feel free to contact me by telephone should you have questions or wish to discuss this further. <br />Sincerely, <br />~t~D s~ <br />Phil G. Schmidt, <br />Engineering Manager <br />cc: David Beny, CDMG <br />Michael Boulay, CDMG <br />Christine Johnston <br />Eric Mende <br />Kirk Mueller <br />Chris Nyikos <br />Kathy Welt <br />