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Response to General Stormwater Comments on March 01, 2011 <br />Adequacy Issue #2 <br />There are drainage structures depicted on Figure SWMP-1 that have no descriptions, details or <br />design/sizing calculations. For example, other than labeling several "debris basins" along <br />existing access roads in Figure SWMP-1, there is nothing else in the SWMP describing their <br />purpose, how they will be sized, design rationale, or how they will be constructed. Please <br />provide a narrative, design rationale, and construction details or sketches for all BMPs shown on <br />Figure SWMP-1. <br />Response #2 <br />The information requested by Mr. Cazier is included in the revised Stormwater <br />Management Plan See Exhibit T-4. Referenced BMPs address the erosion and <br />sedimentation control structures proposed by Wildcat Mining Corporation and provide the <br />size and rationale for the design. <br />Adequacy Issue #3 <br />There are several BMPs (e.g., Temporary Stream Crossings, Storm Drain Inlet Protection, Outlet <br />Protection, and Stabilized Construction Entrance/Exit) from the Caltrans Stormwater Quality <br />Handbooks presented after Table M, Augmentation Pond Construction Runoff Control, that are <br />not shown on Figures SWMP-1 or SWMP-2 and/or discussed in the SWMP, Attachment T-4. <br />Please indicate in the narrative and/or Figures SWMP-1 and SWMP-2 if and where these BMPs <br />will be used, or remove them if they will not be used. <br />Response #3 <br />The information requested by Mr. Cazier is included in the revised Stormwater <br />Management Plan See Exhibit T-4. Referenced BMPs address the erosion and <br />sedimentation control structures proposed by Wildcat Mining Corporation are located on <br />SWMP-1 and SWMP-2. Road BMPs are presented in revised Exhibit D. <br />Adequacy Issue #4 <br />Precipitation amounts: Several Tables (e.g., Table A - Drainage Basin Flow Analysis- Upper <br />Deadwood Gulch Drainage) include references to Technical Paper 40. Please note that TP-40 is <br />not applicable to western Colorado. NOAA Atlas II, Volume 3 or the other listed reference (Peak <br />flows in Colorado by Wilkes, et al) should be used for storm depth estimations. Appropriate <br />references indicate the 10-year, 24-hour storm depth for the site to be approximately 2.7 inches, <br />not the 2.5 inches listed in Table A. <br />Response #4 <br />The 10 year, 24 hour storm depth has been increased from 2.5 to 2.7 inches and is reflected <br />in Table A and other summary tables. <br />May Day Idaho Mine Complex 112(d) Permit Application <br />Revised: April 14, 2011 <br />2