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Mr. Jack Henris <br />July 13, 2016 <br />Page 14 <br />m:\min\tc1\_teller\m-1980-244 cc-v\am-11\m-80-244-am-11maincommentr12016-07-13.docx <br />is the meaning of the “C: 0.50”? If it’s not used in the analyses, remove it from the drawing <br />and replace it with appropriate parameters. <br />59. Appendix 10, Drawing CCVSA11-9. This drawing has two section callouts (X and Y) on <br />each of the three plan views (1, 2 and 3). The profile labeled “4” is assumed to be the “X” <br />section, but it does not show the cut and/or fill for EMP21b. There is no corresponding “Y” <br />section shown on the drawing. <br />a. Why is the cut/fill for section X not shown in the profile? Please resubmit the <br />drawing showing the cut/fill for EMP21b. <br />b. Where is the corresponding Y section/profile for EMP21A? <br />Appendix 10, Design Report for Storm Water Management at the Chicago Tunnel Site <br />60. Narrative Description of Mining Activities, p. 1. The last sentence of the first paragraph <br />states “CC&V has delegated responsibility for the management of the stormwater to that <br />contractor”. The Division has a regulatory relationship with the permittee, not the operator <br />(when different than the permittee). Please acknowledge CC&V is responsible for <br />stormwater management. <br />61. Narrative Description of Mining Activities, p. 2. The top of page 2 states “no measurable <br />or reported discharge has occurred from the [Chicago] tunnel”. This was written just prior <br />to the Division’s December 2014 approval of TR-03, allowing CC&V to reopen the tunnel, <br />which was plugged at the time this 2014 report was written. Please clarify whether any <br />measurable or reported discharge has occurred from the Chicago Tunnel since it was <br />reopened. <br />62. Methodology and Basin Descriptions, p. 4. The bulleted summary of the various basins <br />states exceedingly large times of concentration. A review of the Sedcad model report (see <br />p. 10, “Subwatershed Time of Concentration Details”) explains why. The time of <br />concentration estimates include overland/sheet flow segments significantly greater than 300 <br />feet (e.g., p. 10 of SEDCAD report Stru #1, SWS #1 is 6,063.94 horizontal feet). TR-55 <br />Upland method for time of concentration calculations limits overland flow segments to less <br />than 300 feet (see top of page 15) and based on experience should be shorter as slopes <br />increase. Please review all times of concentration estimates to ensure proper methodology <br />and model input is appropriate. It should also be noted that the first five “Land Flow <br />Conditions” in Sedcad are for overland/sheet flow (see below). <br /> <br />Screen capture from Sedcad, Subwatershed, routing calculations, Land Flow Conditions.