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• To the best of my knowledge, based upon my pt ofessional expertise, and to the extent <br />possible, Pond D10 at [he Yoast Mlne was constructed in accordance with the prudent state- <br />of-the-art of earthen embankment construction. Further, the structure was constructed in <br />compliance with the approved design, to the extent possible, as specified Sn Attachment <br />specified in Attachment 13-3 of Seneca Coal Contoany's approved mine permit. Minor field <br />adj ustmenis in horizontal and vertical alignment were necessary during construction to <br />compensate for unantlcipat ed natural conditions, limit the disturbed area, and construct a <br />structure consistent with the existing and reclaimed topography. The upstream and <br />downstream slopes were flattened and the overall width of the dam increased. This was <br />done based on the wet conditions encountered when the topsoil was removed from Lhe dam <br />locatlori aril ponding area. The toe drain pipe was also changed to a stronger schedule <br />3034 perforated pipe instead of just slotted PVC. <br />To the best of :.,y knowledge and belief, field adjustments made during construction to the <br />structure are it ..onformance with the Rules and Regulations in the intent of the approved <br />design plans and specifications (see Exhibit 13-4A). <br />• <br />Conclusion <br />NOV 12 1996 <br />Date <br />Sedimentation Pond 010 does meet or exceed the design and performance requirements of the <br />CMLRB's regulations. Seneca will inspect the pond quarterly to evaluate structural <br />S ntegrity, storage capacity conditions, and remedial work requirements in accordance with <br />the approved mine permit. Therefore, pursuant to Rule 4.05.61101, the above is the <br />Sedimentation Pond O10 as-built certif is atlon report. <br />Stability Monitoring <br />Upon review of the as-built report for Sedimentation Pond 010, the Division believes it <br />would be appropriate to install several survey monuments on the embankment to verify the <br />stability of the embankment. Seneca will install five monuments on the embankment and <br />13-3A-11 Revised 11/05/96 <br />