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III Il)1111111111111\ <br />• 999 <br />SPo)L F/L-L <br />DISPOSAL OF E}~CrSS SI?~~b <br />Fourth Quarter 2001 Certification <br />Fill Area #7 <br />R~c>~rt~>=o <br />'I fit' 2 ~ 2002 <br />~visionolM;r~rars a L . ,, <br />The CTL Thompson report dated April 27, 2001, "Stability Analysis and Geotechnical Recommendations <br />Lorencito Surface Mine Phase 1" addresses the general requirements as also cited in Sections 4.09.1 to <br />4.09 ~ of the Colorado Mined Land Reclamation Board for Coal Mining. <br />SEDIMENT CONTROL <br />Sediment pond construction has been completed in accordance with plans submitted to and approved by <br />the DMG and as-constructed survey/drawings certified by Registered Land Surveyor and Registered <br />Professional Engineer. All surface run-off from the fill areas is directed to this sediment control facility. <br />SI"fE PREPARATION <br />Organic materials such as brush and trees were removed from the proposed fill area followed by topsoil <br />removal. Design criteria did not require keyway cuts for steeper valleys with minimal soil cover (fill #7). <br />No evidence of springs or seeps w-as observed during site preparation. <br />DRAINAGE SYSTEM (IJNDERDRAINS) <br />• Drain sizes are specified by CDMG regulations for fills which can be classified as Valley Fills. Fill area #7 <br />is not a valley fill. CTL Thompson recommended a minimum 6' x 12' triangular section(area = 64 SF') for <br />[his size fill. As constructed drainages generally were more trapezoidal with a top width of 12', bottom <br />width of S', and average height of 8' (area = 80 SF). Sandstone recovered from durable "channel" <br />sandstone deposits encountered during the mining process were used in drain construction. Mirati 160 <br />fabric was used in lieu of filter material. <br />FILL PLACEMENT <br />CDMG regulations require that spoil be "placed in horizontal lifts in a controlled manner, concurrently <br />compacted as necessary to ensure mass stability". Maximum lift thicknesses are not specified. Lifts were <br />placed in accordance with plans specified by [he CTL Thompson report. <br />Spoil material was transported to the fill area using a combination of trucks and dozers. Left thicknesses of <br />upto ~0 feet were placed within the area removed from the till face by more titan 50 feet. Thinner lifts of 6 <br />[0 8 fee[ with leveling and compactive effort supplied by dozers and trucks will be utilized as fill placement <br />advances [o within fifty fee[ of the slope face. <br />COVER MATERIAL <br />Final fill configuration has not been obtained and no cover material placed on the excess spoil. <br />I~ <br />LJ <br />FiIINo.7 Page I oft <br />