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Gold Hill Mill Ad auacv Review Resoonae Mar 2 1995 27. a) The only available as-built topogtaphrc information and sections were sent to the Division on April 2Q 1995 by Mark Steen of hli Vide Enterprises. We have no documenunon on foundation characterisRCs or foundation atrrfice preparation b) Dtmeruione of the existing starter dam u shown tit plan end close uchone from Mark Steen are: Cteet Elevatiore. NA Crest 1L'idth: f 0 to 11 feet nontirtel Crest [.ertgth: Approx. 370 feet Upatteem Slope Angle I .fi:l to greats than 3:1 Downstrctrm Slope Angle Approx. I.S:I cl No information is ctrrratdy avedable on embankment materials. COM, Ina. wtll attempt to rake samples for analysis as soon es weather conditions allow work on-site to restune. A report dated November t I, 1985 from Denver Ertgureeting Corpomhon indicated that the ceilings pond was constructed to meet plans and specifications d) A cottsttuction ducription letter from MI. Mark Stern, dated July 16, f 987 to the Division, luCs the liner es a 30 trail potyethylerte liner. A copy of the letter ie attached. AQ flaws tit the liner will be patched by a qualified company by the end of Jtme. e) The decant line is a '.-inch HDPE line wtth three risers (open pipe tees) placed at equal distances along the lute. The line rs about 250 feet long and u prated on top of the tailings in the water pottding area. The pipe is connected to a 1-inch PVC standpipe that is I«sted at the south end of the pond. The atandppe goes horrzontallythrough the liner and embenlmtertt at the bottom o(the pond. We have no details on the startdptpe as if goes throtrgh the liner or the embenlatrnt. The 2•ineh PVC pipe u buried to a point just below the beae of the embenktttent where a valve box is located. The 2•inch PVC pipeline then u laid an the sttr(ace of the ground down to tfie Haul A edit (see Erdtibrt A) where the pipeline goer throttgh s short urdirted borehole and into the hori7mital Haul A edit. The pipeline exttmds back tiom the portal apprtntimateiy )0 feet whce the pipeline discharges behind a wooden btdkhead slut contains the water in the mine workutgs that ere connected to the time and Wynona mines. Water 5om heft Hand Crxk is also pumped 3,900 feet through the 2-inch pipeline located ht Akira Gulch end situated on property ptuchescd by C.O.M. Inc. to a point north of County Roed No. 52 where the water litre enter the portal of the Time mint. A bulkhead u constructed in the Time rttine adtt and water is dischuged from the pipe into the Time mute wockirtgs behind the bulkhead. The Time mine adtt passes 45-feet below County Road No. 52 end exttmds 395 feet u. a southeasterly direction where the Time mine u connected with the Wynona mme by a SO-foot dap win7,e. Roth the Time and Wynonn rttittes are being wed to store water for milling operations for the period between Novanber I end May 31. Mill water is drawn from the workittge by pumping the water out of the Wynone mine shaft. 28. a) An upstream raise will nor be used for raising the e:nbatdtrnrnt The base of the starter dike vnll be ~d by going dowtutream _ feet and s~rtrtg a new cmbartkment with 1.5: i upsteam and downstream slopes. The new embardmient will tie into the existing embertlattent and use the upstream slope es paA of Nc upstream slope of the new cmbanktttent. Triaxiel shear and pore pressure test, vn71 be done an samples fttrm the e.~tisting starter dike. bj COM, Inc. curtcrttly plans to rue material'lrpetrcem t4om the existing t°'t' ~. pond as bonow for the new anbenkmmt. The bonow materiel will be tasted as part of the design and specifications that wily be prepared far the new embanlanent Qtutliry a>sirrance testing will be included in the specificahnrts that asli be even to the ditisron For approval prior to embankment coruwction. c) Cross aeetiotu will be included a6 put of the desip2t epecifiea4ona. d1 Desrgri apecificationa for the mnbankmmit will include liner installation and quality esarus~nee spect9canons. COht, inc. does nor plan to erttend the liner nn [rte upstream side of die new embankment, but will include liner installation in the borrow uea ro a point above the find design 511