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..~ <br />RECEIVED <br />INSPECTION OF EXCESS SPOIL FILL <br />Fourth Quarter 2002 Certification MAY 1 ~ 2003 <br />Fill Area No. 8 <br />Date: December 26, 2002 Division of i`Ainerals and Geology <br />GENERAL DESCRIPTION OR REFERENCE TO SITE PLAN: <br />The CTL Thompson report dated April 27, 2001, "Stability Analysis and Geotechnical 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 INSPECTION: <br />Removal of Topsoil and Organic Matter <br />Placement of Underdrains <br />Installation of Surface Drainage System <br />Constuction of Fill <br />_Placement of Topsoil <br />_Seeding <br />X Other Mine idle - no activity this quarter <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 front the fill areas is directed to this sediment control facility. <br />No evidence of significant erosion was observed. <br />SITE PREPARATION <br />As incicated 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 fill placement. Design criteria did not require <br />keyway cuts for steeper valleys with minimal soil cover (fill #8). No evidence of springs or seeps was <br />observed during site preparation. <br />DRAINAGE SYSTEM (UNDERDRAINS) <br />Drain sizes are specified by CDMG regulations for fills which can be classified as Valley Fills. Fill area #8 <br />is a valley fill CTL Thompson recommended a minimum 6' x 12' triangular section(area = 64 SF) for this <br />size fill. As indicated by previous inspection reports, as constructed drainages generally were more <br />trapezoidal with a top width of 10', bottom width of 14', and average height of 8' (area > 96 SF). <br />Sandstone recovered from durable "channel" sandstone deposits encountered during [he mitring process <br />were used in drain construction. Mirafi 160 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 lifr thicknesses are not specified. As <br />• indicated by previous reports, lifts were placed in accordance with plans specified by the CTL Thotpson <br />report. No fill placement occurred during this quarter. <br />