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III. COMMENTS -COMPLIANCE <br />Below are comments on the inspection. The comments include discussion of observations made <br />during the inspection. Comments also describe any enforcement actions taken during the inspection <br />and the facts or evidence supporting the enforcement action. <br />saturation of the steep slope associated with rapid melting of deep snow drifts that had built up along the lee side <br />of the ridge crest over the winter, which was characterized by mild temperatures and above normal snowpack. <br />Roy Karo of SCC had expressed concern during a February 2006 inspection regarding the potential for slope <br />failure, based on the unusually deep drifts observed below the ridge crest in the subject location at that time. <br />The potential for deep drifting below the ridge crest has likely been increased by mining, which eliminated the <br />vertical structure provided by tall mountain shrub and aspen vegetation that previously occupied the site. <br />The failure affected an area of perhaps 20% of the width of the original slide repair area, resulting in a steep <br />sided trough feature, possibly 50 feet wide by 10 to 15 feet deep along the upper portion of the slope, and deep <br />debris accumulation at the ioe of the slope. The deep debris accumulation appeared to have been largely <br />limited to the area previously disturbed in association with the 2001 slope failure and repair, with a very small <br />area of undisturbed aspen habitat impacted by primary debris deposition. One aspen tree was knocked over by <br />the slide debris. A narrow band of "debris runout" had flowed over the snow for several hundred feet along an <br />aspen Swale below the toe of the slide. This resulted in soil deposition several inches thick by 15 to 20 feet wide <br />for several hundred feet along the Swale. It is expected that existing understory vegetation will grow up through <br />the shallow soil deposition, with minimal long term effect. The entire area affected by the slide drains into <br />Sediment Pond 015. <br />Tentative plans for remediation of the slide feature discussed with the operator include regrading of the upper <br />end of the failure to eliminate the steep scarp and reduce the gradient of the slope immediately upslope of the <br />scarp, grading of the "trough" to reduce the side slopes and allow for construction of a stabilized drainage to <br />accommodate future runoff from rapid snowmen and intense rainfall, regrading of the toe slope debris area to <br />remove deep accumulations away from the aspen edge and accommodate drainage channel construction, and <br />vegetative stabilization of the final graded slide areas (and "debris runout zone" as warranted). <br />There appears to be no potential for adverse effect on public health or safety as a result of the slide. Adverse <br />environmental effects are limited to the immediate vicinity of the slide, and can be remediated by grading, <br />drainage installation, and revegetation to be completed during the current field season. Offsite hydrologic <br />impacts are prevented by Sediment Pond 015, located approximately % mile downstream of the slide toe, within <br />the permit area. <br />A complete technical revision application slide remediation plan addressing regrading, drainage <br />installation, vegetative stabilization, and other measures as warranted to ensure long term stability will <br />need to be submitted !o the Division by Juty 1, 2006. The revision shall include a timetable for <br />completion of major tasks and the entire project. Remedial work shall be completed by October 1, 2006, <br />5 <br />