Laserfiche WebLink
Susan Burgmaier -5- December 31, 2012 <br />BRL: West Diversion Ditch #2 has been constructed above gob pile #2 at a 3.5% grade, <br />then the steep section at 22 %. A revised design is included as pages App. B-42 and <br />42i. <br />17. There appears to be an inconsistency regarding the steepness of the hillside cut <br />slope that is proposed for a portion of the expansion area. The third paragraph <br />on Page 1 indicates that a segment of the hillside will be graded back <br />(steepened) to a slope of 1.5H:1 V. On Figure 1, Section F -F' shows a cut slope <br />of 2.0H:1 V through this area. Section F -F' in the Buckhorn report also depicts <br />2.0H:1 V. Please clarify the intended slope ratio to be cut at this location. <br />BRL: The slopes discussed in question no. 17 are for two different locations. The <br />1.5H:1 V cut slope on page 1 was approved with TR -72 and is in close proximity <br />to Section A -A' of Buckhorn's report. Section F -F' will be cut back at <br />approximately 21-1:1V as shown. <br />18. Subdrainage systems for Valley Fill disposal sites are required by Rule 4.09.2(2)(d). <br />An alternative subdrainage system was previously approved by the Division, as <br />allowed by Rule 4.10.3(5). Volume IX page 5 of the current application indicates <br />that the subdrain for CMWDA No. 2 will be extended as shown on Figure 2. While <br />there is nothing to prohibit extension of the subdrain, the proposed expansion of the <br />waste pile in this area does not appear to be a valley fill configuration. The Division <br />suggests that construction of a drain to intercept any groundwater seeps identified <br />would be sufficient. <br />BRL: Please see note added to Figure 2 and Maps 21 -3 and Map 20. <br />Please fee free to contact me if you have any questions. <br />Sincerely, <br />Tamme Bishop, P.E. <br />Project Engineer <br />Enclosures: <br />Volume I: <br />Volume II: <br />Volume III: <br />Volume IX: <br />Pages 2.05 -12, 13 <br />Maps 15 -3, 18, 20, 21 -3, 22 -C, 32 <br />Pages EXH. 8 -11, 17, 18, 19, 29i, 74ix, 74x, 208i, 249, 252, 253, 255, 256 <br />Pages App. B -2, 4, 6, 19 -22, 24, 30, 39 -42i, Figures 1 & 2 <br />