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r10 • 25 90 1 : OJ 'Q`1 a0J 985 2UB0 GOI.DER- ACS <br />• <br />Golder Associates Inc. <br />1~ <br />200 Union 8ouievoro. Sara 5GG <br />lnkewood. CO'JSA dG2?E <br />TPIP.Fhone (~03)98G•05w^ <br />lax (3C3J 9852080 <br />June 28, 1995 <br />Cripple Creek & Victor Gold ?vlining Company <br />2755 Matz Highwa}~ 67 <br />Victor, CO 80860 <br />Attention: Mr. John Hardaway <br />Reference No.: 953-2900.007 <br />RE: UPPER AREQUA GULCH SPRING COLLECTION SYSTEM <br />Dear John' <br />The origina! design of the Upper Arequa Gulch Spring Collection system consisted of a 4 <br />inch diameter SDR 17 HDPG pipe, a spring collection box, and a network of perforated <br />pipe acting as a spring collection system upgradient of the spring. Based on the recent site <br />conditions, this configuration has been modified, and Golder Associates Inc. (Golder) <br />wo•,ild like to take this oppomtniry to discuss these reasons. <br />The basis of the original design assttmed that there would only be one readily identifiable <br />spring located in Upper Arequa Gulch. and that the spring collection box would be <br />located at the focal point of the spring, with a network of pe:forated pipe located <br />upgradient to collect any minor seepage. The spring cntlectinn bnx w•at installed near the <br />end of the 1994 construction season, and was located in a general arcs where the spring <br />was thought to occtu. <br />Stripping operations began in Upper Arequa Gulch in May of 1995, which included <br />clearing and ?robbing, topsoil removal, as well as limited excavaticr.. At this time, i.t <br />became apparent that there were numerous spring located in the Upper Arequa Gulch area <br />and that the spring collection box was not located in the appropriaze location..A trench <br />was excavated a] ong the center of Aregl~a Gulch to dewater the Upper Aregtta Gulch azea <br />and 8 spring locations wen identified. With the large number of seeps occurring over <br />such a wide az°ap the spring collection box no longer sen•ed its intended purpose. <br />The current sprinm collection consists of the 4 inch diameter HDPE pipe placid in the <br />dewateting trench that was excavated along the center of Arequa Gulch. Perforated pipe <br />was placed in the area of the springs, and connected to the 4 inch diameter HDPE pipe. <br />All pipes were bedded in a granular medium. "the remainder of the dewatering trench <br />was baclsfilied with an Underdrain material to provide Ilvw capacity fot drainage from <br />the overlvin^_ material. <br />fd 002 <br />pFFiCcS iN iUS:iU.~:A. ~.:.i.ADi.. GERN..aNV, 4UNt;AG{ itALV SWF[',cN. 7A:'cD ri:NC CA'v7 Ul~RFn S,A?ES <br />