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3. The Division does not approve a stream channel diversion with a lesser capacity than the <br />unmodified stream channel immediately above and below the diversion (4.05.4(2)(b)). <br />4. The Division approves permanent diversions in the reclaimed area. These diversions are the <br />reconstructed ephemeral channels necessary to safely drain the reclaimed lands after mining. <br />The diversions are consistent with applicable state law, will not diminish downstream water <br />rights and meet the requirements of Rule 4.05.4 (4.05.4(3)). <br />5. The permanent diversion shall make use of artificial structural controls in order to allow it to <br />remain in dynamic equilibrium with the drainage basin system. Riprap channel lining will be <br />used in most of the permanent drainage channels on the reclaimed area. The Division approves <br />the use of such structures (4.05.4(4)(b)). <br />D. Sedimentation Control Measures, Ponds and Discharge Structures - Rules 4.05.5, 6 & 7 <br />Thirteen sediment ponds are approved by the Division and 12 sediment ponds are in place to <br />treat disturbed area surface water runoff. These are the Streeter Gulch, Work Area, Gulch A, <br />Gossard Loadout, Stoker Siding, Railway Loop, Prospect, West Pit, East Taylor, and Section 16, <br />Section 21, Section 28 and West Taylor Pond. The Section 21 Pond is approved but has not yet <br />been constructed. Designs for these ponds are included in Exhibit 7 and the locations of the <br />ponds are shown on Maps 12, 12A, 41 and 41 A. <br />1. The Division does not approve of any sediment pond in a perennial stream (4.05.6(1)(b)). <br />2. The Division does not propose to approve the submittal of reports required by Rule 4.05.9(17) <br />on other than a quarterly basis. <br />3. Alternative design criteria and specifications have been approved for use in sediment pond <br />design and/or construction. This decision is based on a thorough analytical demonstration by a <br />qualified professional engineer that the resulting sediment pond will be as environmentally sound <br />and structurally stable taking into consideration physical, climatological and other characteristics <br />of the site (4.05.6(11)). <br />E. Acid-forming and Toxic-forming Spoil - Rule 4.05.8 <br />No significant acid-forming spoil exists within the overburden or coal seams to be mined (PAP, <br />page 2.05-57). Overburden sampling and regraded spoil sampling plans were approved for the <br />East Pit and Section 11 Pit during the first two permit terms. These plans are discussed in Exhibit <br />G and Section 2.05 of the PAP. Results from past sampling are included in the mine's Annual <br />Reclamation Reports. These programs were instituted primarily due to concerns about high <br />sodium adsorption ratios (SAR) in some over- and interburden materials. Analogous sampling is <br />performed in the West Pit and Section 16 Pit. During nine years of sampling of the upper and <br />lower Y seam overburden in the East Pit, only one sample had a suspect SAR value. <br />Proposed Decision and Findings of Compliance 14 September 2009 <br />Permit Renewal 05 Page 37