Laserfiche WebLink
August 2000 Monthly Report <br /> Page 4 <br /> The provisional flow at A-72 on August 2, 2000 was 105 cfs, which places this sample <br /> result in the intermediate flow category (100<Q<300cfs). The dissolved zinc value for <br /> this sample, obtained by averaging the results from two labs, was 390 ug/l. <br /> The index number for the August sample is calculated as follows: <br /> Xi = 390 <br /> Xf= 399 <br /> Sf= 144 <br /> Ni = (Xi — Xf) /Sf <br /> Ni = (390— 399) /144 <br /> Ni = -0.06 <br /> The index number graph and updated reporting table are attached. <br /> Evaluation of the normalized data: <br /> The index value of -0.06 for August 2000 indicates that the dissolved zinc concentration <br /> at the reference point A-72 was close to the mean value of the reference data for the <br /> intermediate flow class even though the flow was near the low flow category. The flow <br /> was so much lower than has been observed in the past for August that a direct <br /> comparison to August concentrations would not mean much. The flow is more <br /> comparable to those previously observed in September through November. For these <br /> months, the observed concentration would be comparable. <br /> The 12 period moving average of index values rose to +0.60 from+0.55. This rise is the <br /> result of a good result N(i)=—0.06 replacing a very good result N(i)=—0.66. This value is <br /> above the +0.577 benchmark value in the Consent Decree where CDPHE may request a <br /> meeting with Sunnyside to discuss the monitoring results. With the flow of the Animas <br /> moving towards base flow conditions early in the season, it is likely that this average will <br /> continue to rise over the next several months. <br /> If you have any questions on this report, please contact me. <br />