Laserfiche WebLink
<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />1313 Sherman Street, Room 215 <br />Denver, CO 80203 <br /> <br />1313 Sherman Street, Room 215, Denver, CO 80203 P 303.866.3567 F 303.832.8106 http://mining.state.co.us <br />John W. Hickenlooper, Governor | Robert Randall, Executive Director | Virginia Brannon, Director <br /> <br />August 16, 2016 <br /> <br />Mr. Jack Henris <br />Cripple Creek & Victor Gold Mining Company <br />100 N. Third Street <br />P.O. Box 191 <br />Victor, CO 80860 <br /> <br /> <br />Re: Cresson Project, Permit No. M-1980-244; <br /> June 16, 2016 Inspection Report Corrective Action Adequacy Review <br /> <br /> <br />Dear Mr. Henris: <br /> <br />On July 25, 2016 the Division of Reclamation, Mining and Safety (Division) received your <br />“Engineering Evaluation of ECOSA” prepared by Paige Cybulski and Tom Byers in response to the <br />Division’s June 16, 2016 Inspection Report Corrective Action 1. <br /> <br />The following comments are based on the Division’s review of the ECOSA engineering evaluation: <br />1) LIDAR scan topographic surfaces. The fifth bullet on the second page references the LIDAR <br />scan area on Figure 3 which appears to be on the order of 2,000 feet roughly north to south. <br />The second to last sentence of this paragraph indicates the slopes analyzed for stability are <br />centered on the seepage area (500 feet wide). It appears from Figure 3 that the width between <br />the two observed seeps is on the order of 450 feet. The Division is uncertain as to how these <br />different widths and areas are reflected in the LIDAR observations and the slope stability <br />analyses. Based on pre-waste dump construction observations, the Division is aware the slope <br />of the native surface underlying the dump increases towards the south end of the dump. Please <br />confirm both the LIDAR scan and the dump slope profiles extend at least 150 feet to either <br />side (and in between) the two observed seeps shown on Figure 3. <br />2) Conclusions. The report indicates LIDAR scanning and visual inspections will continue with <br />results being copied to the CCV S&ER Department. Please commit to providing an updated <br />report to the Division every 30 days during active seepage with a final report based on results <br />obtained 30 days after observed seepage has discontinued. <br />3) Figure 4. The red line (July 7, 2016) appears to be about a 10 feet lower than the blue line <br />(June 6, 2016) at the middle bench (elevation ~130), yet the caption indicates “No movement <br />noted”. Please provide an explanation for this change. <br /> <br />