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10 pg. 1) are different than those reported in the Analytical Report The original total cyanide value in the Quality Control Report for the collection impoundment was 0.26 mg/1, while the concentrations in the Analytical Report were 1.05 and 1.14 mg/1. Similarly, the original total cyanide values in the Quality Control Report for the lower tailings impoundment were 0.29 mg/I, while the concentrations in the Analytical Report were 0.58 and 0.31 mgp. A similar problem exisu for original WAD cyanide values for the collection impoundment sample. The original WAD cyanide value in the Quality Control Report (Appendix D, pg. 6) for the collection impoundment was 0.16 mg/l, while the concentrations in the Analytical Report were 0.62 and 0.72 mg/l. All other concentrations in the Quality Control Report match those reported in the Analytical Report. The values reported in the Quality Control Report area 1:4 dilution made to dilute the color in the sample (personal communication, Core Laboratories, Dec. 28, 1993). If the total and WAD cyanide concentrations reported in the Quality Control Report are multiplied by 4, (0.26x4=1.04; 0.16x4=0.64 mg/I), the concentrations (with rounding) are the same as the first duplicate reported in the Analytical Report. 3.3 LABORATORY TURNAROUND TIME Core Laboratories received the samples on October 13, 1993. The date c+f the Analytical Report from Core Laboratories was November 18, 1993, which is a turnaro+and time of over one month. 4.0 CONCLUSIONS AND RECOMMENDATIONS FOR FUTURE SAMPLING Cyanide concentrations were below detection in Rito Seco Creek and the groundwater wells. WAD cyanide concentrations were above detection in all process point samples, but were less than 1 mg/1 and were lower than those measured during the May 1993 sampling. Total cyanide concentrations were once again highest in the collection impoundment sample. The dissolved oxygen meter was not operating properly during this sampling trip. Measured dissolved oxygen readings were above 700% saturation for the relevant elevations, and all dissolved oxygen measurements (for RS-5, Upper Tailings Impoundment, Lower Tailings Impoundment, and the Col]ection Impoundment) are not considered reliable. Aback-up meter and probe would have obviated this problem with dissolved oxygen field measurements. - Acceptance criteria for laboratory duplicate analyses were not met for total cyanide measurements on both the upper and the lower tailings impoundment samples. The fact that control criteria were not met makes the values RCG/Hagler Bailly