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4.0 CONCLUSIONS <br />An annual site characterization methane assessment was performed east of the Golden Eagle Mine in Weston, <br />Colorado to determine whether methane concentrations in monitoring points have changed over time. <br />The average methane concentrations have shown a decreasing trend in the existing original 22 points that <br />have been monitored since March 1999 (an average decrease from 53.7 to 39.8 percent). Additionally, <br />average methane concentrations have remained nearly the same in the existing 35 points monitored since the <br />2001 monitoring report (an average of 32.3 percent). Vegetation was observed to be recovering during the <br />2005 and 2006 sampling events in areas where methane concentrations had decreased. <br />Measurements from the mine's airshafts indicated that there were high methane concentrations in the former <br />mine workings. The measurements taken from the south airshaft in 2005 indicated a concentration of 88.6 <br />percent methane. The north airshaft was inaccessible during the 2005 monitoring event because it has been <br />reclaimed. The mine workings have represented a potential source of methane in the area; however, water <br />monitoring studies indicate that the mine workings have been inundated, which should minimize any potential <br />for methane seepage to the surface. The effected area of vegetation during the 2000 survey was about 146 <br />acres. The effected area of vegetation during the 2005 survey was about 32 acres, the same as in 2004, and <br />approximately 50.2 acres in 2006. <br />No imminent hazards are associated with the methane seepage other than stressed or dead vegetation. <br />Methane would only be a human or animal health concern within a confined space. <br />2006 Methane Monitoring Report (11.02.06).doc 4-1