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<br />7 UCI'Nn MrNf OI NNl1RAl IIFSC IIIfIC FS ~ `
<br />I1 Mnnlc l'.,,1 .I •~inlrvc Uu r~In,
<br />,varch 11, 1982
<br />~llNlr:l1 I,~NI) lil';I:i.:1i11/1'I'I(1N
<br />4?3 CenlCnnini Ilu drhny. 1313511enn;ur Slreel
<br />I)envcr, Colpr:nl~l H112U3 Tel i3(1J) 8:19 3`.Ifi7
<br />David C. Shelton
<br />Director
<br />'TO: 7bm Millis, 12cclamation Splx~irrlist' C ~~ !1~--
<br />1'R0hi: Jim Iendleton, Senior Geologist ~\~.. :-,~~~~~
<br />RE: Review of Waste Disposal A::pr-ct of Co rado Ncstmoreland, Inc. 's
<br />Orchard Valley Minc' Plan
<br />Pursuant to your request, I' have comPloted a rr_vier.• of Chc amonded permanent
<br />program permit application submitCerl b,l Colorado Westmoreland, Inc. for the
<br />Orchard Valley coal urine. This memorandum presr;nos courrnents For your .
<br />consideration rcyarding the Waste Di:~pusal aspect of that permit application.
<br />Colorado Wes4nareland proposes to dispose of roi:ary Lreaker separated coal
<br />processiny waste in a (:oat Processing Waste Bank projected to cover approximately
<br />one acre L) the steep slope area inuncdlately below the truck loadout at the
<br />Orchard Valley mine.
<br />As referred to Lr my memo of August 12, 1980, which was forwarded to the
<br />applicant, the: proposed disposal sitr~ is Iocaterl Iditlun an arr'a of potential
<br />slope instability, The Colorado Gcolu~lical .Survey (Rahc Junyc, et. a1.), in
<br />accordance r~rith house UiZl 1041 (CR.S 1073, 24-G5.1-1 U1, et. seq.l, has mapped
<br />the Bowie quadrangle and five adjoiniuy quadranylcs to delineate areas of
<br />geologic hazard that could cause an economic loss or affect the safety of the
<br />citizens of Colorado. Copies of the l,urtion of that map which contains
<br />the Orchard Valley surface focilitie_~ and the corresponr/.inq explanations are
<br />attached to this memorandum for the ~r1.pZicant's information. The maps divide
<br />the area of the mine's surface impror,•ments into arras designated as "Potentially
<br />Unstable Slope", "Potentially ilnstaLlc Slope and Expansive Soil or Rock", "ROCkfaI1",
<br />"Rock fall and 6'xllansive Soil or Rock", and "Sheet Flow Flooding and Erosion".
<br />The entire Orchard Valley surface. fal~ititg area is designate<1 as one or another
<br />po ten tia.i gcol odic hd zo rel.
<br />The specific site of the prol'orcd C,'o,,l 17ocessinq Wa::tc H,nll: is ~:pecifically
<br />designated as "I'otcnCia.lly (rnsCablc ~I~+pc and I:xpansivc .`,'oil or 12ock". I
<br />Lave examincl7 low al titurie (1:6,000 sr:.11e) storcographic aerial photography
<br />of the Orchard Valley permit ama, f]r.tan under contract for Cho Colorado MLRD
<br />on September 19, 1980. As is characl~•ristic in P.he area~of the Notth Fork of
<br />the runnison i2iver, the mine site's yrnmorphic surface features suggest numerous
<br />past episodes of mass mnverncnt phenorm.wa (landslidinu, rock fall, etc). Discrete
<br />slope tailures uro cvirlent on flee p)rnl„graphy in thr_ uphill slope of the
<br />permanenr divr~rsi~)n ditch IocaCed nr .'re upslupr, Loundarq of the surface facility
<br />(con l 'r!)
<br />~I
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