2016-07-28_REVISION - M1980244 (2)

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RESPONSE. A revised Figure ]-] is provided in Attachment 2 with the different drainages mentioned in the report shown and labeled on the figure. • Page 4: The text indicates that multiple EMPs may exist for the Wilson Creek drainage. However, Figure 1-1 appears to show only EMP-006. Is EMP-006 the only EMP associated with the Wilson Creek drainage? RESPONSE. The text of the report will be updated to reference only one EMP in Wilson Creek drainage. Note that EMPs (Enhance Management Practices) are the final terminus control for stormwater management at the site. Several BMPs (Best Management Practices) are installed upstream of the EMPs. Each drainage is different and detailed stormwater designs have been conducted for each drainage at the site and appropriate BMPs and EMPs installed. The stormwater designs for Wilson Creek drainage were designed and constructed pursuant to past permit amendments. As stated in Section 3.1.1 (Page 4), there are no changes proposed for Wilson Creek under Amendment 11. As such, no additional stormwater designs were considered. Please refer to the Design Report for Storm Water Management— Amendment 10 and 11 for details on EMPs designs. In addition, CC&V maintains a site-wide Stormwater Management Plan, which details stormwater management practices for the entire site. • Page 4: The text states that the North Fork of Wilson Creek(Theresa Gulch) is shown on Figure 1-1. However,this drainage is not labeled on Figure 1-1 as either North Fork of Wilson Creek or Theresa Gulch. Please revise Figure 1-1 to label this drainage. RESPONSE. A revised Figure 1-I is provided with the different drainages mentioned in the report shown and labeled on the figure and is included in Attachment 2. 3.1.1 Amendment 11 • Page 4: The text states"The activities associated with AM-11 do not propose to construct new or expand existing facilities in the Wilson Creek drainage" and"the EMPs will continue to operate as currently permitted". However, as shown on Plate 15 Hydrology Impact—Surface Mining, AM-I I operations are to include expanding the Main Cresson Mine southward to create the South Cresson pit. Could these activities potentially impact the Wilson Creek drainage? Have you considered installing additional water monitoring stations and possibly an EMP in the area south of the soon to be expanded South Cresson pit? RESPONSE. The text in Section 3.L I (Page 4) is correct. There are no new mining activities in the Wilson Creek drainage as part of Amendment 11. Plate 15 from the Hydrology Impact—Surface Mining Report shows the final contours/mining sequence of the mine areas at reclamation. This has not changed since Amendment 10. There is no expanded mining in the Main Cresson or the South Cresson mine areas resulting from Amendment 11 and as a result there is no need to add monitoring locations in Wilson Creek as part of this Amendment. 3.1.2.1 Monitoring Program • Page 5: The text lists a total of 6 surface water monitoring stations, including T-1, T- 2,T- 3, WCSW, BCSW, and WCSW-01. However, only stations T-2 and WCSW-01 are shown on Figure 2-1. It is the Division's understanding that you intended to show the locations of only compliance monitoring sites on Figure 2-1. However,there is a discrepancy between the number of stations shown on Figure 2-1 and the number of compliance sites,which creates some uncertainty as to which sites listed throughout this evaluation you consider to Page 15 of 28