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C- 1981 -008 TR -60 <br />Preliminary Adequacy Review <br />15- Aug -2011 <br />Page 4 of 4 <br />Public Health and Environment Water Quality Control Division on March 23, 2011, reflects the <br />addition of Pond 013 to the list of ponds to which mine dewatering may be directed. The <br />amended portions of the permit became effective on May 1, 2011; the permit will expire on <br />March 31, 2012. <br />The Division has no adequacy concerns with the new discharge permit. However, the title of <br />Attachment 2.05.3(3) -18 has been altered with the addition of "JUNE 30, 2013 ". Please delete <br />this date from the title; it does not appear to correlate with any dates associated with the <br />discharge permit, and is confusing and unnecessary. <br />Attachment 2.05.3(3) -24 Pond 015 As -Built <br />a) Under the "Design" section on page 1, the three -year projected sediment accumulation is <br />given as 0.002 acre -feet. The volume anticipated in the Pond 015 design [Attachment <br />2.05.3(3) -22] was 0.04 acre -feet. Please provide an explanation for the 95% percent <br />reduction in predicted three -year sediment accumulation for Pond 015. <br />b) As -built parameters for Pond 015 are provided on page 4. The Curve Number (CN) has <br />been reduced to 75.5 from the 83.5 presented in the original design for Pond 015. USLE <br />inputs are tabulated on page 6, and an "Erodibility" value of 0.37 is used for each of the <br />different land use categories in this table. Please provide an explanation as to how this <br />number was derived. <br />7. Map 2.05.3(3)-19 Pond 015 As-Built— Contours and Cross Section <br />a) Please identify the limit of sediment storage elevation on the Cross Section <br />b) Please generate an additional cross section running through the low point on the outer <br />berm. <br />c) The table in the upper right -hand corner appears to duplicate the Stage - Storage Report on <br />page 6 of Attachment 2.05.3(' ))-24. Please delete the table from this map, to avoid any <br />future confusion. <br />8. Map 2.05.3(3)-20 Pond 015 As -Built Ditches and Culverts <br />The watershed area acreages on this map are shown in very small font. Please increase the font <br />to an appropriate size. <br />This concludes the Division's preliminary adequacy review for TR -60. Please contact me with any <br />questions you may have as you prepare your response to this review. <br />Sincerely, <br />Marcia L. Talvitie, P.E. <br />Environmental Protection Specialist <br />xc: Ross Gubka, P.E., Western Fuels — Colorado <br />Sandra Brown, DRMS <br />