2016-08-10_GENERAL DOCUMENTS - M1981185 (2)

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Final -Restoration and Compliance Plan for May Day Idaho Mine Complex Administrative Order for Compliance, Docket No. CWA-08-2012-0011 the fill/culvert option. The Durango office of the Corps agreed with use of this alternative in a July 16, 2012 email; the USEPA concurred with the use of this alternative in an August 14, 2012 email. The fill/culvert option, which is shown on Figure 6, entails the removal of all of the recent (2009) fill material and restoration of the hydrologic functions of the Little Deadwood Gulch channel. This plan meets the engineering and safety standards for the Mine. The culvert will be sized to pass up to the 100-year flood. The owner will commit to maintaining the culvert to minimize the potential for debris blockage. 5.3.2 Mine Access Road A plan to correct the deficiencies with the Mine Access Road between La Plata County Road 124 and the La Plata River was submitted to the DRMS on April 10, 2012. The DRMS approved the plan in a letter dated May 23, 2012. The owner has obtained approval for the road from La Plata County. A variance was needed from the county since the road grade exceeds the county's standard of 12 percent. The plan focused on the approximate 500-foot reach of the mine road constructed on the steep hillside adjacent to the La Plata River between Stations 18+00 and 20+00 on the plans. The design in this area was based on recommendations in a geotechnical study for the project. Figure 7 shows the proposed access road plan and profile in this reach. Figure 8 shows the retaining wall grading plan. The erosion control plan is shown on Figures 9a and 9b. The plan for the Mine Access Road was completed in May-June of 204. An as-built of the work in this area is included in Appendix F. BWC-SGM observed the work at the Mine Access Road on May 17, 2016 and also reviewed the plans and as-built drawing for the work, including the stormwater pond. Based on this, it appears that the work was completed generally consistent with the plans. It should be noted that the design for the retaining wall did change during the construction process, but these changes affected the height and nature of the wall and did not increase the footprint of the wall and road or increase the amount of wetland impact. The scope of work for the new Mine Access Road was as follows: • The limits of wetlands in the project area were marked in the field. June 2016 Bikis Water Consultants, a division of SGM Page 11 Case 1:16-cv-02008-WYD Document 2 Filed 08/08/16 USDC Colorado Page 41 of 82