Laserfiche WebLink
• Kathy Welt <br />January 11, 1995 <br />Page 4 <br />• Construction Requirements: <br />The development waste pile will meet all the requirements of section <br />4.10.4. The pile will be build in lifts not exceeding 24" and will be compacted <br />to 90 % of standard proctor. The development waste coal will be isolated <br />"inside" the development waste rock by covering the development waste coal <br />with a minimum of six feet of development waste rock. The slope of the pile <br />will not exceed 2.5h : lv. Three feet of subsoil and one foot of topsoil will be <br />placed on the pile during reclamation. <br />• <br />• Subdrainage System: <br />As addressed in a previous, approved revision, a series of subdrains meeting <br />the requirements of section 4.09.2 is planned to be installed underneath the <br />- mine waste development pile as shown on figure LPG - 103G & 104G. The <br />main drain will be install along the natural drainage and will extend to within <br />five feet of the toe and head of the fill. Two lateral drains will be placed to <br />intercept any potential drainage or seepage water. The rock to be placed will <br />be sized so that no more than 10 % of the rock will be less than 12" in size. <br />The main underdrain will be 10' in width and 4' in height. <br />• Surface Water: <br />The design of the required water drainage facilities was addressed in a <br />separate letter. <br />If you have any questions please give us a call. <br />Sincerel , <br />/J~~ ~-- <br />Charles C. Rehn P. E. <br />CCR/tp <br />• <br />