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INSPECTION OF EXCESS SPOIL FILL <br />Third Quarter 2004 Certification <br />Pill Area No. <br />Date: September 30, 2004 <br />GENERAL DESCRIPTION OR REFERENCE TO SffF. PLAN: <br />The CTL Thompson report dated April 27, 2001, "Stability Analysis and Geo-technical Recommendations <br />Lorencito Surface Mine Phase I" addresses the general requirements as also cited in Sections 4.09.1 to <br />4.09.2 of the Colorado Mined Land Reclamation Board for Coal Mining. <br />ACTIVITY DURING INSPF,CTION: <br />Removal of'I'opsoil and Organic Matter <br />Placement of Under-drains <br />Installation of Surface Drainage System <br />-Construction of Pill <br />_Placement of'fopsoil <br />-Seeding <br />SEDIMENT CONT120L <br />Sediment pond construction has been completed in accordance with plans submitted to end approved by the <br />UMG and as-constructed survey/drawings certified by Registered Land Surveyor and Registered <br />Professional Engineer. All surface run-ofFfi~om the fill areas is directed to this sediment control facility <br />known as pond 7. A 100-yr 24-hr storm event occurred on August 5-6, 2004. No significant erosion <br />occurred to this facility as a result of the stone and no erosional problems were noted during this inspection. <br />The pond discharged as a result of this event with some flow passing through the emergency spillway. No <br />evidence of significant erosion was observed <br />in ., <br />SURFACE DRAINAGE <br />Armored Ditches line the east and west boundary ofthe fill area. Lateral ditches on the fill face direct <br />runoff to these side ditches. Some of the large rock armoring the down drains was displaced by the August <br />storm event. This rock has since been redistributed returning the channel profile to design configuration. <br />Additional rock is scheduled for placement No erosional problems were noted at the intersections oCthe <br />lateral ditches and the armored ditches <br />S[TE PREPARATION <br />As indicated by previous inspection reports, organic materials such as brush and trees were removed from <br />the proposed fill area followed by topsoil removal prior to (ill placement Design criteria did not require <br />keyway cuts for steeper valleys with minimal soil cover (fill ft9). <br />DRAINAGE SYSTEM (UNDERDRAINS) <br />Drain sizes are specified by CUMG regulations for fills which can be classilial,as Valley Pills. fill area N9 <br />is no[ a valley fill CTL Thompson recommended a minimum G x 12' Triangular section(area = (,4 SP) for <br />this size fill. As indicated by previous inspection reports, as constructed drainages generally were more <br />trapezoidal with a top width of 12', bottom width of 8', and average height of 8' (area = HO SP). Sandstone <br />recovered from durable "channel" sandstone deposits encountered during the mining process were used in <br />drain construction. Mirafi 160 fabric was used in lieu of filter material. <br />