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<br />' Homestake Mining Company -Bulldog Mine•Lower Tailing Pond <br />10 <br />' Although the data summaries for each of the monitoring wells were found during the file <br /> seazch, no field logs were found that would indicate the condition ofthe well, whether <br /> the samples were turbid and to provide field measurements such as pH, temperature and <br />' conductivity. In addition, only the parameters of primary concern at the time were <br /> analyzed; cyanide (free), lead, zinc, and copper (all measured as total). Based on a <br /> conversation with Bob Boppe, who performed some of the sampling, samples were <br />' always difficult to obtain, were usually turbid and were razely filtered. He further <br /> commented that the wells had such a low yield that obtaining a fresh sample by pumping <br /> wasn't possible. Therefore, samples were always bailed and, as the water elevations <br />' declined, the samples were difficult to secure and were always turbid. In addition, no <br /> sampling protocol and Chain-of Custody were established. Samples could have been <br /> contaminated during saznple collection or at the Bulldog Mine's laboratory, where the <br />t analysis was performed until the mine was closed in 1985. At that point, the analytical <br /> work was performed at Rocky Mountain Analytical Laboratory in Denver but samples <br /> were still collected by HMC maintenance personnel at the mine. <br /> As reflected on the data plots, Figures 3-9, after the remediation work of 1982-1983, the <br />' cyanide levels declined sharply in relationship to the declining water levels in the <br />monitoring wells. The water levels in WP4 dropped approximately 5.5 feet from 1984 to <br /> 1990 when the well was dry. The cyanide (free) concentrations went from 3.5 in <br />' December 1984 to 0.01 in August 198d. It remained near or below detection levels from <br />that point forward. In 1981-83, WP25, the predecessor to WP4, showed a considerable <br /> decline in the cyanide concentrations after the remediation activities, with levels <br /> dropping from 26 ppm in September 1982 to <0.01 ppm in September 1983. th addition, <br />' as shown on Table 1 and Figure 3a-c, the pump-back water in the pond receded rapidly <br /> after operations were curtailed in January 1985. Without new tailings being added to the <br /> pond, the constituent levels in the pump-back water and the monitoring wells also <br />' dropped off. This was reflected in all the monitoring wells. However, several spikes <br /> occurred throughout the testing period in lead, zinc and copper. This likely occurred <br />' because of the difficulty in securing samples, the samples not being filtered, and total <br /> rather than dissolved values being tested. Regazdless, as reflected on the data plots, the <br /> trend certainly indicated that the combination of successful remediation and no further <br />' use of the tailing facility after January 1985 combined to eliminated the problem. In <br /> April 1991, the WQCD agreed with the trend when the requirement for ground water <br /> monitoring data in the CDPS permit was eliminated.. In June 1993, final samples were <br />' secured from monitoring wells WP29, 30, and 31. (Well WP4 did not contain water). <br /> The cyanide (free) in each of the wells was below detection. <br />' c) Private Wells Monitoring <br />HMC initiated a private well sampling program in 1981. This program, was undertaken <br />' by mine staff and the analysis performed at the Bulldog Mine laboratory. Well samples <br />were collected on several private well located approximately down-gradient from the <br />' Lower Tailings Impoundment. The Deacon, Quiller and Lancaster wells were located in <br />~I <br />