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HDH TECHNOLOGIES INC <br />June 25,1992 <br />TEL:303-792-5b33 Jura 25 92 13:21 No.G03 P.02 <br />Dr. James A Pendleton <br />Mined Land Reclamation Division <br />1313 Sherman Street, Room 215 <br />Denver, Colorado 80203 <br />Dear Dr. Pendleton: <br />After discussions with Dr. Posey and yourself at the MLRB hearings yesterday, I took some <br />time to do a quick plot of the data which Battle Mountain Gold (BMG) presented on their <br />cyanide detoxification since June 15, 1992. In preparing these plots, I have used their data <br />of WAD cyanide levels somewhat above 200 ppm an June 15, 1992 rather than the value of <br />130 ppm on this date attributed to you in the Denver Past this morning. Not having seen <br />the original data on which the BMG graphic was based prior to the hearing, I can only <br />assume that the 200 ppm figure is real. <br />The two curve fits, one a linear regression and the other an exponential decay regression <br />both have very similar RZ wefficients for measure of fit with 0.91$ and 0.905 for the CORE <br />data on linear and exponential fits, respectively, and 0.958 and 0.936 for the DBGUSSA <br />data on linear and exponential fits, respectively. With the limited data set available (6 <br />CORE analyses and 9 DEGUSSA analyses), I would not want to jump to major conclusions <br />on which of these is the best extrapolation of the data at this goint. <br />I will appreciate seeing future data on the ryanide assays as they come through your office, <br />as you indicated would now be done, in order to follow the cyanide trend as we move <br />toward the July 3, 1992 and July 20,1992 deadlines. With regard to these analyses, I have a <br />couple of questions whicfi bear on the use of this data which I hope you maybe able to <br />answer: <br />1. Are these analyses taken on a daily basis from a single point in the <br />pond, from several laterally dispersed points, or from several dispersed <br />points and varying depths so that we can judge the presence of <br />stratification and heterogeneous distribution of the cyanide? <br />2. Are there any analyses being done on these ,amples by the approved <br />total ryanide analysis method (EPA method with manual finish, for <br />example) in order to verify the precision and accuracy of the WAD <br />analysis by the picrate method? <br />L062592DEH1 <br />