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[NSPECTION OF GXCFSS SPOIL hfLL <br />Fourth QuarLcr 2004 Cati(ictllion <br />Fill Area No. 7 <br />Date: December 30, 2004 <br />GENERAL DESCRIPTION OR REFERENCF,'1'O SITE PLAN: <br />The C'fL Thompson report dated April 27, 2001, "Stability Analysis and Geo-Technical Kecunmtendotions <br />Lorencito Surface Mine Phase 1" addresses the general requirentenls as also tiled in Sections 4.U9. I to <br />4.09.2 of the Colorado Mined Land Reclamation hoard for Coal Mining. <br />AC'PIVITY DURING INSPECTION: <br />Removal of Topsoi(and Organic Matter <br />Placement of Under-drains <br />Installation of SnrfaCC Drainage System <br />Construction of fill <br />Placement of Topsoil <br />Seeding <br />X Other None, facility tr'as idle throuout the fourth quarter. <br />SEDIMENT' CON'PROL <br />Sediment pond construction has been completed in accordance with plans submitted to and approved by the <br />DMG and as-constructed survey/drawings ccnificd by Registered Land Surveyor and Regi.etcrcd <br />Professional Hngineer. Occasional precipitation as snowfall during the quarter resulted in uo i nn-off nor <br />erosion. Additional rock remains to be placed in fhe armored down-drains. <br />SURFACE URAINACE <br />Armored Ditches line the east and west boundary of the till area. Lateral ditches on the f ill face direct <br />runoff to these side ditches. A fourth east-west ditch was constructed at the upper rnost extent of the fill, <br />connecting to both Armored ditches on the east and west perimeters. Some of the large rock armouring the <br />down drains was displaced by the August storm event. 'this rock has since been redistributed returning the <br />channel profile to design configuration. No erosional problems were noted at the intersections of the lateral <br />ditches and Ute armored ditches. <br />SI'i'B PREPARATION <br />As indicated in previous inspection reports, organic materials such as brush and trees were removed from <br />the proposed fill area followed by topsoil removal prior to fill placement. Design criteria did not require <br />keyway cuts for sleeper valleys with minimal soil cover (lilt !17). No evidence of springs or seeps was <br />observed during site preparation. <br />DRAINAGE SYSTEM (UNDERDRAINS) Drain sizes arc specified by CDMG regulations fur tills which <br />can be classified as Valley Dills. Pill area l17 is not a valley fill. L"I'L Thompson recommended a minimum <br />G x 12' triangular section (area =(4 SI'') fur this size fill. As indicated by previous inspectiun reports, as <br />constructed drainages generally were more trapezoidal with a top width of 12', bottom width of 8', and <br />average height of 8' (area = RO S1'). Sandstone recovered Gom durable "channeP' sandstone deposits <br />encountered during the mining process was used in drain construction. Mirafi I(0 fabric was used in lieu of <br />filter material. <br />