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MEMORY TRANSMISSION REPORT <br />PAGE :001 <br />7161E :AUG-01-03 17:22 <br />TEL NU618ER1: +13038663567 <br />NA61E :Colorado Division of Minerals & Geolo&y <br />FILE NU618ER 566 <br />DATE AUC-Ol 17:19 <br />TO : 83032749329 <br />DOCU6~NT PAGES 010 <br />START T16~ AUG-O1 17:19 <br />END 716¢ AUG-O1 17:22 <br />SENT PAGES 010 <br />STATUS OK <br />FILE NU6BER :566 *** SUCCESSFUL TX NOT 1 CE *** <br />STATE OF COLORADO <br />OIV[SION OF M[NEINLS ANO GEOLOG)L__, __ _ __ _ _ __ _ ____ _____ _ <br />Department of Natuml Rasourcas <br />pbonplC Fax Note 7671 Ps[a ~ (~ O w- ~~ <br />J Qlt~ s~ F.en. ( Lra iu <br />~JO ...tk Csa.sse n°~ l7 wL <br />PNana ~ Pnon <br />Faits SOZ-Z - -` Ftaa. <br />Ca~LO RpADO <br />MIN ~RALS <br />G E O L O G Y <br />TO: Kale Picl[ford aill.Jwann <br />PROM: Allmss Soxvtsaom ~' ~ O^`. [~`^r tartar <br />Eaaer+elva p <br />RE: Ptr Wes!( 3tobirtry and Srrboc/aJYOIr[ Valuable Srrvcrv'rs, Hslr Pfs <br />Pilr Na M-3003-OI6 Ivan of nro..rcn'[nsren <br />The Division of Minerals aced Geology (DMG) has completed a etabiliry analysis for the mined pit wills at the <br />ptopoeui Heit Gv-avel Pic Thm reaulcs of [he analysis axc attached to chin memo. Tlve DMG•a arability analysis di F to <br />Ham Han analysis provided in the permit application in Hove ways. <br />1. 'IIa¢ DMO riaodel¢d rlfc pi[ wa11 as vei-[i¢al fade whereon the Apphcan[ uamd a O-SH:I V pat well. It is viu ta:[]ly <br />mposaible to control gravel mining at a highwall so as to assure the F c ..rill no exceed an arbitrary sme. a <br />angle. The DMO frequently obsecv¢a verleal and near vetucal highwalla ac gravel pits. <br />2. The DMO does nor agree [lea[ the bedrocK tmder/ying [tae Heit sand and grnv¢l deposit is '• nfin:tely atror g" as <br />um¢tl Lor the purpose of tfi¢ Appl[cvnt•a analysis. The bedrocK in ihiv location i• Aae Cmtacvoua ~ aierre <br />HhslaasThe upper [hzae or mox i'vet of thin lxdrocic is wcatlacted and is an over consolidated or stifF Fiasa red <br />clay. Thv weathered slaate~ upon unloading, may Mgcvde to a Nlly soRemed or residual aaxengtb condidc a and <br />exhibit very low sfimar strength. The DMO ran a nu mb¢r of models acttinII tfie weathered bedttacK at its <br />residual atreaagdv Hownvnr_ as the a[mchcd analytic nl resvl[s show. Hoe bedrocK material is not :nvolvad n the <br />eriHea3 Pailura surfaces in this Particular cage. <br />3. Tlae applicant modeled a ptogreca:va Aails+ty W[fi initial pit face slottghiog Followed by analysis of the tee silting <br />slope eoxa8gumdon. '1'hn DMO arvalyaia eiders s bulk Failure daa[ could impact atructu[va ¢t she propc sad <br />25 Foot a¢ebaeK ]ins doting the initial slumping. <br />DMG's anNyeia ahowa that the 25 foot setback propoecd by eha Apptimnt is inadequate to protect valuable ahtacc area. <br />A[ n 40 Foot aetbacK a metastable slope with a 1.01 anPory [iam[or reauka. Oivea the comervsdsm of Ate maumed s hear <br />atmragth patametera itaput to Ate uzaalysia and tfie temporary natum of clae mincd highwslle, DMG has determined t hat ¢ <br />40 foot s¢cbacK is eu Pficicnt. To verify Shia 1-indirag, an analysis was conducted a[ a 40 £oot aetbacK with tlvv int¢rt al <br />friction angle For the sand and grmvel d¢poa(e nut nt 35 deg[eca (increased 4om 30 degmrs Wcd in [he other nvaly[ ca). <br />A 35 degree Triction angle for the send and grnvel material is a xasonable atW still conscrvativv ¢xpecmtion. A e:.fbty <br />factor of 1.22 wan Ave maul; which is quite sufHcirnc Por temporary slopes. <br />1313 5he[man 5[.. Room 315 <br />Oanv,er, Culorrdu ae2P3 <br />Pftmne: 13091 B6b356] <br />FAX: (3031 833-8106 <br />DATE: August 1, 2003 <br />The Applicant should co[>as[i; or the DMG should edpulam, m - o t[uy occur no clostu~ Atnn 40 fnv[ w structuro~ <br />aFForded proc¢cdon under $3432.5-115(4)(e) C.R.S., Lapd Reclamation Ac[ for the Fxti-action of COna[rtacrion <br />Maseaiala. Thies conmaixrraen[ or stipulation will only apply where the Iimita of mining illununt .d on tlto mnpa prop idad <br />with doe permit apPlim clovatr then 40 T s[ to pmm¢tad amactu[na. Wlaero tho Iiztti[a of m[taing shown on d a <br />avapa ate grvamr than 40 R¢t. chose depleted rNrain8 limits will bo eavfbrcenble. <br />anacluncngs) <br />cc. Carl Moun; DMG (vln small ~ w/o etNosterr. J <br />Tug Martin, Banks and Gesso fi.fa for, w/arlacAlnwns. and Per' X/tP dtsscsYOnJ <br />e:\aca\MY Oucumantfvw,t Dll.tloo <br />OTirn oI <br />MInW LanC Raclima[ien <br />.\eu.a ana m.aNa Mm.. <br />f_Olnradu <br />~eoleg.cal Su[ycy <br />1 <br />