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<br />acceptance by Peabody Coal Company of one stipulation. The .stipulation concerns a <br />road fill stability analysis as discussed in the Roads sn_ction of this document. <br />XIX. ROADS <br />Eleven miles of haul roads currently exist within the permit area, but the applicant <br />plans to increase this to 16 miles as the southern and eastern reserves are mined. <br />L~sign of haul roads is based upon the anticipated volume of traffic, weight and <br />speed of the vehicles using them. The roads section of the application is found <br />in Volume VI, Tab 12, p. 12-20. <br />The applicant has not sufficiently addressed the requirements of Rule 9.03.1(3)(d) <br />(iv),(v),(vi),(vii)and (viii) on embankment construction. Some of the spoil in <br />the area proposed as construction material is acidic. Such material can be used <br />only in embankments described in 4.03.1(3)(d)(iv), which must be addressed in the <br />permit application. The size of rock, method of placement, moisture content, and <br />compaction in embankments should also be explained in accordance with paragraphs <br />(v),(vi),(vii) and (viii). <br />The following stipulation is necessary to determine compliance: <br />SENECA COALS LTD. MUST ADDRESS THE USE AND CONTROL OF ACIDIC MATERIAL IN <br />EIdBANKMENT CONSTRUCTION IN ACCORDANCE WITH SECTION 4.03.7 (3)(d)(i v) WITHIN <br />30 DAYS OF PERMIT ISSUANCE. SN ADDITION, TILE REQUIREMENTS OF 9.03.1(3)(dJ <br />(v),(vi),(vii) AND (viii) MUST BE ADDRESSED AND INCLUDED IN THE APPLICATION. <br />Peabody Coal Company proposes to use and requests a variance to apply alternate <br />specifications for ditch-relief culvert spacings per Rule 4.03.1(9)(3)vi). Inten- <br />tions are to carry drainage to existing major, incised channels which are already <br />cut to bedrock. The Division approves this variance in culvert spacing. <br />In areas where ditches discharge onto open slopes, measures to provide protection <br />against erosion of the hillside and control of such runoff both within and outside <br />of the permut area have not been addressed. Therefore the following stipulation <br />is necessary: <br />WITHIN 30 DAYS OF PERMIT ISSUANCE, TILE APPLICANT MUST DESCRIBE MEASURES TO <br />PROVIDE EROSION PROTECTION AND RUNOFF CONTROL IN AREAS WHERE DRAINAGE <br />DITCHES DISCHARGE ONTO OPEN TERRAIN. <br />A 110-foot fill embankment on the main haul read is a non-complying structure which <br />was built For "life-of-the-mine" use prior to August 3, 1977. The drainage area <br />behind it is 632 acres. Up to this point there has been no problem with ponding <br />water or stability, but a tecluiical analysis was requested by the Division. A <br />stability analysis was submitted on July I4, 1981. The report analyzes the pseudo- <br />static slope stability of the embankment under both dry and the 100-year, 29-hour <br />maximum storm's water stand. As such, the analysis embodies several unique, <br />innovative techniques. It is, in the Division's opinion, in keeping with the prudent <br />state-of-the-art of geotechnical stability analyses. <br />A probabilistic approach is utilized by the consultant to determine appropriate <br />materials strength parameters for use in the analysis of the embankment. This <br />technique is based upon a regression analysis of penetration blow counts. The <br />Lower 95~ conficence level for cohesionless materials is used to project an <br />appropriate angle of internal friction of 39 degrees. The lower 95% confidence <br />