1985-12-22_HYDROLOGY - M1984049 - Laserfiche WebLink

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Table No.2: Approximate Permeability of Tailings • Well No. K; cm/sec M1A 0.032 M1B 0.042 M7C ~ D.D25 M2A '= 0.052 M2B 0.025 M2C O.D54 M3A D.024 M3B 0.037 Water level measurements are given in Ta61e No,3. As previously noted, slight increases in water levels occurred in all injection monitor wells except M2C. There was also a gain in the water levels in the other monitor wells which was permanent in nature, due to the increasing precipitation as summer advanced into fall. However; the increase in the injection monitors was, for the most part, temporary and the levels receded after the injection was stopped, indicating communication between the tailings and the underlying ground water. WATER QUALITY Surface and ground water samples were collected at 24 • locations as shown on Figures 2 through 12. The sampling was conducted both to initiate the monitoring of base line water quality and to investigate the possibility of leakage of the tailings ponds. Ground water samples were collected 6y an inert gas sampler employing nitrogen for its operation. All samples were filtered and preserved at the site. The parameters of temperature, pH, conductivity and salinity (as ppm CaC03) were measured at the time of sample collection. It was not possible to sample monitor well MW-2 (site no. 29 on Figure No. 15) because of high concentrations of fluorescein dye in the well, as previously described. In addition to base metals and mercury, the samples were analyzed for iron, managanese, cyanide and chromium as the presence of these compounds would be considered diagnostic of pond leakage. Sample descriptions and results are given in Ta61e No.4. The distributions of certain parameters are shown on Figures 3-13. Law concentrations of cyanide were detected at five locations; however its presence was not detected on repeat sampling at one of the locations. The cyanide was detected in the currently impounded pond water and at two locations • -12-