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<br />Cold Hill Mill Adeauacv Review Re~ponae Mav 2 1995 <br />2~. n) The only available as-built topogtnphte tnfotmatron and sections were srnt to the Division on Apri! 24 <br />1995 by Mark Steen of Mi Vide Enteryroa. We have no doctunmtation on Coundation characteristics <br />or foundation srsrface preparation. <br />b) D¢nenaions of the existing starts dam es shown in plan and cross sections from Mark Steen are <br />Crest Elevatlon: NA <br />Crest 0.'idth 10 to 12 feet nosttutal <br />Crest l,errgth: Approx. 370 feet <br />Upatrettm Slope Angle l.ti:l to greets than 3.1 <br />Dowrutreem Slope Angle Appmx I S:I <br />cj No infarrrtation is cturendy available on embanknmt materials. COM, Inc. will attempt to take <br />samples for aztalysu u soon es weather conditions allow work on-site [o resume. A report dated <br />November ll, 1985 from 1Jasva Estgineering Corporation indicated that the tailings pond was <br />constructed to meet plans end specillcatroro <br />d) A constnution discription letter from Mt. Mark Stern, dated July l6, 1987 to the Division, Lsts the lists <br />m a 30 rtul pOlyethylata line[. A copy oClhe letter u attached. All [laws in the lima will be patched by <br />s qualified company by the rnd of June. <br />e) The decent line is a .-tneh HDPE line wtth three risers (open pipe tea) placed at equal distances along <br />the line. The line u about 250 feet long end u placed on top of the tailings to the water pottding azu. <br />The pipe is connected to a 2-inch PVC standpipe that is lacaud at the south and of the ptmd. The <br />standpipe goes ho[itontally tluottgh the liner and embankment at the bottom of the pond. W e have no <br />details on the standpipe as it goes thrnttgh the liner or the emberti~ttmt The Linch PVC ppe u booed <br />to a point just blow the base oC the embankment where a valve box is kxakd. The 2-inch PVC <br />pipeluse then u laid ten ttx surface of the ground down to the Hazel A edit (sa Exhibit A).whae the <br />pipeline goes through a short tuduted borehole and into the horiznttml Nazel A edit. The pipeline <br />extends back from the portal apprordmately 30 fat where the pipeline discharge behind a wooden <br />bulldsead that contains dta atida in the mine workings that are wnrtected to the Time and Wynona <br />mines. W eta fiom Leif Hand Creek is also pumped 3,900 feet through the 2-inch pipeline looted ct <br />Aldrts Gulch enG situated on property ptuchased by C.O.M. Inc to a point north o[Cotutty Road No <br />52 where the water line enter the portal oCthe Titne mine. A bulkhead is cosuIIUCted in the Time urine <br />edit end water is discltatged from the pipe into the Time mine workings behind the bulkhead. The Tune <br />mine edit passes aSfeet below County Road No. 52 and extends 393 feat to a souttteastedy direction <br />whet[: the 15me mine u connected with the Wynona mine by a SO-foot dap winxe. Both the Time and <br />Wynona rrtirta ere being used to store water for ttullirtg opc[etioru for the period between Novanber I <br />and May 31. Milt casts ie drawn from the workings by ptunping the casts out of the Wyttone mine <br />shaft. <br />28. a) An upstream raise wi0 not be used for raising the anbttrtkmrnt. The base of die starter dike will be <br />rnlarged by QwtB downstream feet and sterbrtg a new embanhnent vvirh L.5:1 upstream and <br />dowrotream slopes. The new embenlanrnt soil! Ce into the existing embe»lattmt and use the upstream <br />slope u peA of the upstnem slope of the new embenlanent. Triaxial shear and pore pressure tests wd1 <br />be done on samples from the existing starts dike. <br />bj COM, Inc. currrntly Plans to tae mate[ia1'ltpstrelatt @aro the existing tailings pond as bonow for the <br />new embtutlanrnt. 1Tte bortew mntaitil will be tested as part of the design and specifications that will <br />tx prepared for the new embanlanrnt Qttehry assurance toting toil! be included in the specifications <br />that will be given to the division for approval prior to embanlottrnt wnstruction. <br />c) Cross sectiotu wiU bt included as put ofthe destgrt spetafications. <br />d) Dmgn epecifieations far the embenktttmtt wdl include line vtamUstion std quality ustuanos <br />spenlScations. COM, Inc. does nor plan to extend the Ilner on the upsvaem alde of the new <br />embankment, but will include liner installation to the borrow azaa to a point above the fins! design fill <br />