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c RECEIVED INSPECTION OF EXCESS SPOIL FILL Il 2003 Fourth Quarter 2002 Certification MAY 1 Fill Area No. 7 Date: Decetriber 26 2002 Division at Minerals and Geology GENERAL DESCRIPTION OR REFERENCE TO SITE PLAN: The CTL Thompson report dated Apri] 27, 2001, "Stability Analysis and Geotechnical Recommendations Lorencito Surface Mine Phase I" addresses the general requirements as also cited in Sections 4.09.1 to 4.09.2 of the Colorado Mined Land Reclamation Board for Coal Mining. ACTIVITY DURING INSPECTION: Removal of Topsoil and Organic Matter Placement of Underdrains Installation of Surface Drainage System Construction of Fill Placement of Topsoil _Seeding X Other Mine idle - no activity during this quarter SEDIMENT CONTROL Sediment pond construction has been completed in accordance with plans submitted to and approved by the DMG and as-constructed survey/drawings certified by Registered Land Surveyor and Registered Professional Engineer. All surface run-off from the fill areas is directed to this sediment control facility. No significant erosion was observed during this inspection. SITE PREPARATION As indicated in previous inspection reports, organic materials such as brush and trees were removed from the proposed fill area followed by topsoil removal prior to fill placement. Design criteria did not require keyway cuts for steeper valleys with minimal soil cover (fill #7). No evidence of springs or seeps was observed during site preparation. DRAINAGE SYSTEM (UNDERDRAINS) Drain sizes are specified by CDMG regulations for fills which can be classified as Valley Fills. Fill area #7 is not a valley fill. CTL Thompson recommended a minimum 6' x 12' triangular section(area = 64 SF) for this size fill. As indicated by previous inspection reports, as constructed drainages generally were more trapezoidal with a top width of 12', bottom width of 8', and average height of 8' (area = 80 SF). Sandstone recovered from durable "channel" sandstone deposits encountered during the mining process were used in drain construction. Mirafi 160 fabric was used in lieu of filter material. FILL PLACEMENT CDMG regulations require that spoil be "placed in horizontal lifts in a controlled manner, concurrently compacted as necessary to ensure mass stability". Maximum lift thicknesses are not specified. As indicated by previous inspection reports, lifts were placed in accordance with plans specified by CTL Thompson. Spoil material was transported to the fill area using a combination of trucks and dozers. Left thicknesses of up to 50' were placed within the area removed fran the fill face by more than 50 ft. Thinner lifts of 6-8 fr. with leveling and compactive effort supplied by dozers and trucks was utilized as fill placement advances to within fifty feet of the slope face. No fill placement occurred during this quarter.