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March 22, 2010 9 <br />The main drain was constructed in accordance with the approved design. Suitable sandstone fill was <br />used for the rock core. This sandstone was sized with a maximum width of 5.5 feet, and did not exceed <br />25% of the channel width. Additionally, less than 10% of the rock fill was less than 12 inches in width. <br />The rock was spot checked with a Schmidt Hammer, and had an estimated compressive strength in <br />excess of 3500 psi. A minimum rock fill depth of 16 feet was achieved. The completed section of main <br />drain was covered with either Mirafi 140N or Mirafi 14ONC filtration fabric. Rolls of fabric with a 15 foot <br />width were used, and a minimum overlap of three feet was used in placing the fabric. The fabric was <br />weighted to prevent wind from substantially altering its placement. The main drain has been completed <br />as designed from Station M-36 to its termination at Station M-47. <br />2.3 Installation of Surface Drainage Systems <br />Surface drainage systems were not constructed during this quarter. <br />2.4 Placement and Compaction of Fill Materials <br />Fill material was placed during this quarter. Fill was placed in the Northern edge of the HGF by dozers <br />and the Molly Brown dragline. This fill was inspected for stability, and no appearances of instability, <br />structural weakness, or other hazardous conditions were observed. <br />The bulk of fill material for this quarter was placed by Komatsu 830E-AC haul trucks. Dump areas were <br />designed as the access to the lower portion of the HGF was constructed. GPS equipped dozers were <br />used to knock down truck placed spoils, assuring construction consistent with the approved design. <br />With the exception of the 7370' dump (the lowest within HGF), all dumps were limited to 50' in height, <br />in accordance with the approved design. The 7370' dump was designed with a maximum dumping <br />height of 100' to allow for gravity separation of materials. The fill placement was consistent with the <br />approved design, and prudent construction methods. Photograph 13 depicts the extent of fill <br />placement near the end of the quarter. <br />Major snow accumulations are cleared prior to placement of fill. As fill material is placed above a <br />previous dump level, the surface of the previous dump is ripped with a D-10 dozer to prevent the <br />formation of perched water tables. This activity is depicted in Photograph 14.