Laserfiche WebLink
8 <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-12. 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/1. <br />M-13. Duplicate samples were again taken at well M-13. Total and WAD cyanide were <br />below detection for both M-13 samples in October, 1993. Duplicate analyses for all analytes <br />except for zinc were within control levels of ±20%RPD. Zinc concenrtrations were <br />±50%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 flee May, 1993 <br />sampling. The pH of the well water at location M-13 has been consistently decreasing over <br />the past year. <br />3.1.4 Quality Control Samples <br />Field and Rinse Blank. The field blank and rinse blank again used second-stage DI water <br />from the BMRI laboratory. Total cyanide, WAD cyanide, calcium, and copper <br />concentrations were all at or below detection in both the field and rinse blanks. The rinse <br />blank had relatively high concentrations of sodium, but calcium concentrations were <br />significantly lower than those measured in the May, 1993 rinse blank. <br />3.2 QUALITY CONTROL ANALYSES AND RESULTS <br />Quality control results related to process point laboratory duplicates were discussed above <br />in Section 3.1.2. The Quality Control Report is included as Appendix D of this summary <br />report. Core Laboratories used a number of samples from the fifth third-party monitoring <br />trip to perform spike and duplicate QA/QC analyses. The identity of the sample (e.g., M-9) <br />is noted in Appendix D next to the analysis I.D. Core Labs was specifically recpuested to run <br />QA/QC analyses on the process point samples upon receipt of the samples. <br />The following samples from the fifth third-party monitoring trip were usecl for cyanide <br />QA/QC spike analyses: upper tailings impoundment (total and WAD cyanide); lower tailings <br />impoundment (total and WAD cyanide); collection impoundment (total and WAD cyanide); <br />field blank (copper, zinc, sodium and iron); M-9 (total and WAD cyanide;); and M-13 <br />duplicate (WAD cyanide). The following samples were used for cyanide QA/QC duplicate <br />RCG/Hagler, Badly, Inc <br />