2010-11-19_PERMIT FILE - C1992081A (3)

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area exemption. Railroad Loop: The railroad loop was constructed in the 1979/1960 period. All disturbance associated with the construction of the loop has been topsoiled and successfully revegetated with a stabilization seed mixture (identified as DHG [Revegetated Hayden Gulch Disturbance] in Tab 10, Vegetation). Total revegetated area associated with the railroad loop is approximately 70.8 acres. The disturbance area is shown on Exhibit 12-1 (Revision 14, dated 03/07). Runoff for a majority of the railroad loop does not drain to either of the sedimentation structures. In order to demonstrate that the railroad loop meets the intention of the Rule 9.05.2(3), a SEDCAD+ analysis was conducted on the entire reclaimed section of the railroad loop. The SEDCAD+ analysis and all associated inputs are presented in Appendix 12-2, Sma11 Area Exemption Demonstrations. As shown in the analysis, due to the successful revegetation efforts the peak settleable solid concentration is below the water quality effluent standard of 0.5 [nl/1. Given these results HGTI requested, and received CDRMS approval to permit this area as a small area exemption. Areas 1 and 2: There are two small areas (Areas 1 and 2) which were disturbed during construction of the loadout facilities area. The location of Areas 1 and 2 are shown on Exhibit 12-2, (Revision 11, dated 03/07). After construction of the Loadout, the areas were topsoiled and successfully revegetated with the DHG stabilization seed mixture. Total revegetated area associated with the Areas 1 and 2 is approximately 0.6 and 0.4 acres, respectively. Runoff from these areas does not drain to either the Truck Loop Bond or the Rail Loop Pond. 2n order to demonstrate that the areas meet the intention of the Rule 9.05.2(3), SEDCAD+ analyses were conducted on both revegetated sections., The SEDCAD+ analyses and all associated inputs are presented in Appendix 12-2, Small Area Exemption Demonstration. As shown in the analysis, due to the successful revegetation efforts, there is no runoff from either site. Given these results HGTI requested, and received CDRMS approval to permit this area as a small area exemption. HG Shallow Well No. 1 and Water Pipeline A water-supply well and associated pipeline were installed in the 1978/1979 time period as part of the original loadout facility construction activities by the previous owner/ operator/pexmittee. Following installation, the disturbed ground was revegetated. The locations of the water-supply well and associated pipeline corridor are shown on Exhibit 12- 1 (Revision 14, dated 03/07). The estimated extent of the disturbed area are 0.39 acres for the HG Shallow well No. 1 and MR-15 5 Revised 03/07