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Mr. Jack Henris July 13, 2016 Page 13 m:\min\tc1\_teller\m-1980-244 cc-v\am-11\m-80-244-am-11maincommentr12016-07-13.docx the lowest, non-gated, gravity flow outlet structure. So, unless there is a low level outlet, the detention pond must be assumed to be full to the spillway invert at the onset of the design storm. Please re-evaluate and re-design as appropriate all AM-11 ponds and their spillways with this approach. 54. Appendix 10, Integration of Chicago Tunnel Site (p. 7). The last paragraph states “most of the facilities have been constructed to meet those criteria”. Which facilities have not been constructed to meet the design criteria? 55. Appendix 10, Figure 1 (p. 8). The schematic shows Basins PG-A1, PG-B1, PG-C1, and PG-F1 being routed to EMP-09 until 2021, then after 2024 being routed to EMP-21. Where are these basins being routed to between 2021 and 2024? 56. Appendix 10, Revised Globe Hill Mine Perimeter. As alluded to in Comment No. 39b above, the proposed Globe Hill Mine pit interception of Poverty Gulch is potenti ally problematic. Plan views 1 through 13 on Drawing CCVSA11-10 include a callout for a “Bypass Pipeline”, which is unacceptable for reclamation/closure design. Furthermore, the last bullet on p. 10 (Appendix 10) states “CC&V is evaluating an alternative design for a stream bypass system that will intercept the flow in Poverty Gulch above that location, convey it around the mine to the Poverty Gulch streambed and discharge the flow into Poverty Gulch using a suitable energy dissipation structure”. CC&V must commit in writing to the Division that no surface mining activity (including topsoil stripping and overburden removal) will take place within 400 feet of Poverty Gulch until a technical revision is submitted and approved by the Division for an acceptable reclamation/closure design alternative to the pipeline. 57. Appendix 10, Drawing CCVSA11-6. There are some discrepancies in the channel details: a. Details 2, 3 and 4 show channel and swale designs with four and six inch design depths. This does not appear to include any freeboard which is t ypically six inches (for small channels) or at least half the velocity head (v2/2g). How much freeboard is included in the design and provide rationale for the freeboard design approach. b. The drawing has section callouts A, B and C. Where are Sections A, B and C? c. There is a reference to the “Primary Drainage Channel on Back Side of Shop – 2”W x 8” Deep”. Where is the detail for this channel? d. There is a reference to the “Ditch along Road, 6” Deep x 24” Wide”. Where is the detail for this ditch? 58. Appendix 10, Drawing CCVSA11-7. The first bullet on page 4 of this document indicates runoff was estimated using SCS Curve numbers. The basin parameters listed on Drawing CCVSA11-7 present “C: 0.50” suggesting the rational method was used. Furthermore, Sedcad output, which does not use the rational method, is provided in Appendix 10. What