Laserfiche WebLink
C <br />I'agc J <br />Tom Ci 1.I is <br />March 1.l, loR] <br />~~ <br />1. The results of complete physical analyses (Iithologic• and textural) of <br />Lhc bcdrr,ck, dilluvium arnl wa::CC maf r ials cncrnurtcrrd. HocJ: reel soil rncchanica <br />pnramcb:r del.~:rnrinaLinm:, iuc.lurlinrJ ulCiuci(:c and residu,:rl :;lro,rr strength <br />(angle oC .intcrnai friction and cohr•:ion), for boCh clfect.ivc• stress earl total <br />stress conditions. Mechanics testirrl should utilize Lr_stinry techniques appropriate <br />for the material earl hydrologic conditions existing at the site. Appropriate <br />density/cnmpoction naatinns (I'roctnr analyses) should b~• determined For use in <br />completing thr~r stability analysis of the proposed waste hank. If jointinu or <br />fracturing .is determined to be an iniJ.ortant structural element, mechanical <br />testing should inc•lurle determining th„ strength parameters of jointed <br />speciments. <br />Thc. amended CWI application contains no discrete laboratory testing results. <br />Shear strength /,ammeters are develol~,•d by correlation with penetration testing, <br />which is extremely crude. Material •r:;swnptions of this sort ace inappropriate <br />for a site with known potential stability problems. <br />9. Thr_~ resu.lts o.f complete cl:cmica! analysis of the roof, floor and interburden <br />(Projected waste material sources) oricountered within thr_• developed areas of <br />the Orc7ianl Palley Mine and recoverc•J in riri.llin9 programs. The required chemical <br />analyse.; arc presentcrl on the nttach,~,l IisC of "Dasclinn Overburden Chemi::al- <br />hiineral Anal ysis". <br />The chemical analyses included r,'ithin C'WI's arnenrlerl application are <br />inadequate f:o c•haracLr•ri.zr_ the "acid-forminy, toxic-forming, or alkalinitV- <br />produciny" nature of f:he anf:icipatrd waste material (Rule 2.04.G(2)(a)(iv)(D)). <br />Additional analyses should bn c•onq,lefrd to properly determine the nature of the <br />projected coal processing waste. <br />5. A projection of waste nuterial production, based upon .empirical data or <br />approptiatr~ analyses of resource data. <br />The aun,nd,~•d application project ~. a rate of waste production of approximately <br />.06 percent of the coal production [a LC. As such, Orchard Valley is exemplary <br />among Colorado coal mines. however, .late from nearby mines in similar stratigraphy <br />(Sorro::rs~: t, ILnJks fJrS t, Cbal basin au•1 hlt. Gwur i::on) r•uy{/esL rates of waste <br />production nuv~unl urd,•rs nC magni f~u•h~ yrca to thtw Lhat projcc LCd by CWI for <br />the Orch~rrl Va1le,l. I'nr f:his rea%nn rhr• projected r.rte of was CC production <br />ahpoans suepect, l,,rrticul~rr7y in a wining reyinn noted Ibr roof failures :urd ' <br />snnrlstonc :;pan;. 'J'he. onlrJ supportiv•~ ::tatcmcnt p.ruscnLcrl in the application <br />to justify the projer.turl rate of waste production is a reference to information <br />provided by C6II personnel. More definitive documentation will have to be <br />included within the application to support the waste production rate projected <br />by CNI. Tf Lh•• prnjr•c•tcd r.itc rnnai~h~rcrl back::tuwrnr( of war.tr• rack or goal <br />pr oc,':^.:irnJ wn:af i~ wif:hin thr• mi nr• war F~nV:~, this; :;Irunlrl Ac dc:;r.•rih::rl, as requi rc•d <br />(sour '.I) <br />