2006-04-03_REVISION - M1977526 - Laserfiche WebLink

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Exhibit D MINING PLAN Unless specifically discussed below the methods described in the 1977 and 2005 mining plans will remain unchanged. Existing sloping, grading and shaping plans will apply to portions of the new area since they are similar to the area now in the permit. This amendment does not add area to the permit but only changes the mining and reclamation plans for the EXPANSION AREA SOUTH LEAS). Original we were to file a Technical Revision to address mining and reclamation in on this area. In early 2004 during planning on this are we did not know if it was feasible to mine this area due to the setbacks along the river, and adjoining properties. In September 2005 we found out that LaFarge was planning a slurry wall for their Stagecoach Pit and that the wall would run along our south boundary. They were approached about possibly extending it into the EAS and making it part of the Stagecoach Reservoir they have planned (Permit #M- 1983-067). It was decided that this would solve how we would deal with removing the gravel and reclaiming the small area covered by the EAS. The 2005 Amendment noted that the newly added area, EXPANSION AREAS NORTH AND SOUTH, would be mined as a dry pit by dewatering them. No specific plans were given for the EAS because at that time we did not know how to mine this area. It became worth while when incorporated into the LaFarge's Stagecoach Reservoir. Frei and LaFarge have a contractual agreement for LaFarge to mine and market the reservoir area owned by Frei on the south end of the EAS. With the slurry wall in place LaFarge plans to mine the south area by pumping water trapped within the slurry wall into the South Platte River. Then progress from their mine into the Frei area. They plan to mine the exterior slopes at their final rate of 3:1 slopes along the slurry wall. The attached map shows the location of the slurry wall within the EAS. On the north end of the EAS we will use the method described in the 2005 amendment. This means that mining between the EAN and the slurry wall will be done by extending the working face south thru the northern end of the EAS. The south end of the EAS will be the last area mined by LaFarge from their Stagecoach Pit and the north end of the EAS will be mined when the EAN is complete. AttacYzed i.s a crspy s.':.u.rx.•y rrra`.1. desi.g33 docuzner:t p.~epared by F9eere and Ault C'onse:Staats, Inc. `.Chat describer the slurry wall des.i.gn and proposed const.ructia33 methods. Also attached is tk:e ('.onstruction Ol~servaLions Report for the Slurry wall (QAQC). It desrri.be the test.3.r3g arld monitr~.r.ix3g done ley tY3e ex3gineers as tYle wall was constructed and concludes that- tl:e ;vall *n~as instal~ed as designed. 4