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8 <br />measured total and WAD cyanide concentrations of the process point locations. Copper <br />concentrations were approximately half of those measured in May 1993 and were the lowest <br />measured during the third-party sampling period. <br />3.1.3 Groundwater Samples <br />Groundwater Wells. Both total and WAD cyanide concentrations were again below <br />detection (at 20 µg/I) in all groundwater samples, although the total cyanide determination <br />on sample M-9 was conducted two days beyond the 14-day holding time (see letter, <br />Appendix E). As stated for the tailings impoundment samples, analysis beyond the holding <br />time results in measurement of concentrations that may be lower than those actually in the <br />sample. The total cyanide concentration measured was below detection, the value is <br />considered invalid and rejected because actual concentrations may be higher in the sample. <br />However, unlike well M-13, this well has never had a measured total or WAD cyanide <br />concentration that was above detection. Consequently, resampling is not necessary, although <br />the total cyanide value itself is rejected. Metals concentrations will be discussed below. <br />MM=9. M-9 again had the highest calcium and sodium concentrations of the three <br />groundwater samples. Detection limits for copper, iron, and zinc were lower than those in <br />May 1993, and concentrations of these three metals were consequently all at or above <br />detection in October 1993. Calcium and sodium concentrations were nearly identical to <br />those measured in May 1993. <br />M-12. Copper concentrations were below detection in M-]2. Calcium and sodium <br />concentrations were again nearly identical to those measured in May 1993. Because of <br />improved detection limits, zinc concentrations were slightly above detection (20 µg/1), and <br />iron concentrations were above detection at 90 µg/I. <br />M-13. Duplicate samples were again taken at well M-13. Total and WAIp cyanide were <br />below detection for both M-13 samples in October ]993. Duplicate analyses for all analytes <br />except for zinc were within control levels of ±20%RPD. Zinc concentrations were <br />X50%RPD, but the values were so close to the detection limit of 10 µg/1 that acceptable <br />control levels are ±(detection limit), and the control levels were therefore met. Copper <br />concentrations were below detection. This well again had iron concentrations that were <br />significantly above detection and that were the highest of the three groundwater wells. The <br />pH value in well M-13 was over one pH unit below that measured in the May 1993 <br />sampling. The pH of the well water at location M-13 has been consistently decreasing over <br />the past year. <br />RCG/Hagler Badly <br />