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W.W. Wheeler & Rssoc TEL:1-303-761-2802 Rug 31 93 12:34 No .002 P.02 • • ~ ~ ~ ~Ifde~f Afld AiiOC~OteSs II~i• 1 ~Q~ ~i3SQU1Ce5 Engineers August 31, 1883 Mr. Jay Jonas Climax Molybdenum Co. Henderson Mine Box 68 Empire, Colorado 80438 Re: 111070 Hsnderson IYline, Hyllnuic Conduotlv- fh of Precwnbden f)rartits in Upper pear Crank Arse Dear Jey: In response to your question about the measured permeability of the berirock in the Woods Creek valley, we believe that the packer tasting that was performed by Golden Orilling Co. and k,gged by Kumar end Asaoc., Inc. et Urad fast May is repreacmtetive for nominally trecturod but unfaulted Silver Plume granite in the valley bottoms. Three NX holes were rotary drilled Into bedrock at the plant fiN dike end standard packer tests were performed as prescribed by the U.S. Bureau of Reclamation in 'Design of Small Dams. The holes wero drilled 6-ft, t 2-ft, end 18-ft imo bedrock and were located generally at and adjacent to the low-point (or thslweg) of the valley near the original atreambed. The tests were conducted et peps presauroa of 20 to 30 psi end the singb•packers were installed just below the badrockiailuvium intartsce. The cakwlatad hydraulic conductivity for the three holes were zero Ii.e. no take at 28 psq, 285 feet per year, antl B feet per year for the 5-, 12- and 18-ft. holes respectivery. This is equivalent to 0, 2.7E-4 tan/aec, and BE-8 cm/sec in metric units. We Relieve that the teat on the middle hale (2.7E-4 cm/sec) is not representative because the ground had been disturbed by blasting in the early 1880's. Therefore, the tests on tndisturbed betlrock Intlicate that the hydraulic conductivity of bedrock near the surtace -will be less than BE-B cm/aec. Please call if you have any queatbna. Very truly yours, r~J~HE~R A A Ix., INC. r Stsvan D. Steffan , .E. SDS:ads 3700 South Inca Street Englewood, Colorado BO110 (303) 761-0130 FFlX (303) 7G1.480Q