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<br />0 <br />,,~°'-~~y sss <br />0 <br />~' <br />COLORADO I DEPARTMENT OF HEALTH <br />4210 EAST 11th AVEP UE•DENVER, COLORADO 80220• PHONE 320-8333 <br />December 1l3, 1979 <br /> <br />Timothy C. Smith <br />Supervising Environment. 1 Engineer <br />Cotter Corporation <br />9305 West Alameda Parkw.y <br />Lakewood, Colorado 802 6 <br />Dear Mr. Smith: <br />DEC 2 u 1979 <br />MiN"r_D LAND RcCIF"^^T~~;~d <br />Colo. Dept. of Ndtlfei .,,;;owces <br />f-i L c ~ , ~ .. ~ 00 <br />This letter is in regar~ to the November 29, 1979 site visit of the <br />Schwartzwalder ore sorter by Mike Brown of this Department. Mr. Brown <br />was accompanied by Ed M Grath, Attorney for Cotter Corporation an~i <br />Tim Smith, Corporate En ironmental Engineer. This Department would like <br />to express its apprecia ion to Mr. McGrath and Mr. Smith. <br />Several issues involvin the operation of the ore sorter warrant artention. <br />This Department serious y questions the sensitivity of the current pre- <br />sorting system to detec small amounts of high grade ore intermixed with <br />waste rock. This conce n arises when one considers the attenuation of <br />gamma photons by surrounding waste rock and railcars. Therefore, ::t is <br />possible that ore can b- deposited as waste rock. Even at a cut o1:f grade <br />of 0.015% U308, the was a rock can contain up to 42 pCi/g of 226Ra (Environ- <br />mental Protection Agenc; comment 32-1-12.). Large deposits of wasl:e rock <br />were observed during the last site visit. The importance of these large <br />quantities of waste roc' and possibly ore deposited as waste rock i.s <br />realized when one consi-ers the possible contamination of Ralston (:reek. <br />Rain, especially if it s acidic, may be capable of leaching some °26Ra <br />from the waste rock or re. Radium, once leached, may remain in sc~lutlon <br />and as such, may be car ied into Ralston Creek as runoff. Specifically, <br />the following issues mu.t receive an in-depth analysis for your license <br />application: <br />1) the total amount of caste rock deposited in the valley, <br />2) the amount of waste rock deposited pest year. <br />