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1.General Pond Information <br />The purpose of this report is to demonstrate that all the sediment ponds at the New Horizon 2 Mine <br />will be permanently stable and the embankments will have minimum long -term safety factor of 1.3. <br />As of the PR -05 Amendment, the New Horizon 2 Mine will have 7 sediment ponds, numbered from <br />Ponds 007 through 013. Ponds 007 and 008 are within the original permit area and ponds 009 <br />through 013 are within the year 2000 amendment area. All of the existing and future ponds have <br />embankments have the following characteristics: <br />- that are no higher than 10.0 feet measured from the original ground at the center of the <br />embankment to the top. Some ponds have some incised storage volume. <br />- top width of at least 10.0 feet. <br />- sideslopes of 2.5H:1.OV on both the outer and inner slopes. <br />- high compaction due to the material and equipment available on site. <br />- a principal spillway pipe and an emergency spillway cutout in the dam. <br />As of PR -06, Pond 010 has been removed from the permit and was never constructed. Pond <br />015 was added to the permit, and constructed in 2011 (See Attachment 2.05.3(3) -24). Pond <br />014 was constructed in 2004 and reclaimed in 2009. <br />A cross - section of the typical pond is shown on Drawing 1 of this report. In the amendment area <br />ponds, a keyway will be dug at the bottom center of the embankment for added stability, although <br />this keyway will not be assumed in the analysis to be conservative. Also, the cross - section used <br />for the analysis shows a downward - sloping original ground surface away from the embankment. <br />This is conservative since all the ponds except for Pond 015 have a mild original ground surface, <br />and Pond 015 is completely incised in bedrock. <br />Attachment 2.05.3(3) -15 -3 <br />