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INSPECTION OF EXCESS SPOIL FILL <br />First Quarter 2005 Certification <br />Fill Area No. 8 <br />Date: March 30. 2005 <br />GENERAL DESCRIPTION OR REFERENCE TO SITE PLAN: <br />The CTL Thompson report dated Apri127, 2001, "Stability Analysis and Cleo-technical Recommendations <br />Lorencito Surface Mine Phase P' 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 Under-drains <br />Installation of Surface Drainage System <br />_Construction of Fill <br />-Placement of Topsoil <br />-Seeding <br />X Other Maintenance <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 rua-offfrom the fill area is directed to this sediment control facility <br />also known as Pond S. A 100-yr 24-hr storm event ocarrred on August 5~, 2004. The pond discharged <br />as a result of this event with significant flow passing through the emergency spillway and over the <br />embankment. Both armored down-drains incurred significant erosion with the flow undercutting the <br />armoring and eroding the sub-base. The operator reestablished the drainage system as soon after the <br />storm even[ as conditions allowed. The lateral drainages have been reestablished but as soon as surface <br />conditions allow, these ditches need to be graded and reseeded. <br />SITE 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 fill placement. Design criteria did no[ 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 (iTNDERDRAINS) <br />Drain sizes are specified by CDMG regulations for fills which can be classified as Valley Fills. Fill area <br />#8 is a valley fill. CTL Thompson recommended a minimum 6' x 12' triangular section(area = 64 SF) for <br />this size fill. Under-drain system was extended down slope to allow establishing the designed slope <br />criteria for the final slope (assuming no resumption of mining). The typical dimensions of the extended <br />drainage generally were more trapezoidal with a top width of 10', bottom width of 14', and average height <br />of 8' (area > 96 SF). Sandstone recovered from durable "channel" sandstone deposits encountered during <br />the mining process were used in drain construction. Mirafi 160 fabric was used in lieu of filter material. <br />