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1 <br /> <br />' Installation of a conduit (pipe) was considered and discarded because of <br />the depth (15' +/-), difficulty of excavation, and probable impact on stat~ility <br />of the slide. The pipe would need to be rigid (Reinforced Concrete) and the <br />' potential forces oP the slide still may crush the pipe. <br />The secondary problem oP mitigation of slope movement is one more <br />heavily reliant on seasonal weather conditions, primarily moisture Prom both <br />' rain and snow. The road ditches along the haul road are likely a contribt,tory <br />source to moisture being allowed to enter the shale layer. Paving of the road <br />ditches with asphalt would likely help carry the water through the slide area <br />' to some extent. Diverting runoff down the hill on the North side of the haul <br />road would also help and possibly a pipe under the haul road to carry South <br />ditch runoff in the same direction would help. For the most part, the slope <br />movement problem will need to be tolerated and this section of roadway <br />monitored and repaired as required to remain operational and safe. !t is <br />unlikely that a catastrophic slide or "blow-out" would occur given the apparent <br />stabilizing nature of the slide below the road. <br />' CONCLUSIONS <br />The instability of the slope along the Snyder Quarry Access Road is li.tely <br />' a natural one aggravated by construction and use of the road for mining <br />operations. Notification of the problem to proper regulatory authoritie;~ as <br />suggested in Mr. Aeifner's report together with an acceptable remedial plan of <br />action will likely prevent any negative jurisdictional actions. It will also likely <br />' address the citizen's complaints. <br />~ It is our opinion that the impoundment of the water doesn't constitute any <br />' real hazard to downstream properties in the event of a large rainstorm. The <br />vastness of the blockage would prevent any breach or "dam failure" releasing <br />the impounded water all at once. Erosion along the release corridor -the <br />slide/natural ground interface - may occur to some degree, but not <br />' significantly. The impoundment is not, however, desirable or something that <br />can or should remain. <br />A controlled plan for filling the impoundment with available slide material <br />together with lowering the "high water line" by excavation of an outlet trench <br />in undisturbed material should combine to eliminate the problem. This should <br />' be accomplished with the knowledge, recommendation, observation, and <br />supervision of a geotechnical consultant who can react to the mechanics of the <br />slide relative to this recommended disturbance. <br />' The delivery of the necessary equipment for this work to the work site is <br />a problem that needs further consideration. IP the slide continues to move in <br />subsequent years, it may be necessary to perform some type of trench <br />t excavation and filling again at a later date so the construction and obliteration <br />of an access road may not be the best approach. <br /> <br />4 <br /> <br />