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EXECUTIVE SUMMARY <br />This report presents an annual methane monitoring summary of all activities conducted neaz the former <br />Golden Eagle Mine located near Weston, Las Animas County, Colorado. The objective ofthis summary was <br />to present data collected in 2003, 2004 and 2005 that quantifies the extent of impacts. In addition, the results <br />presented in this report indicate a decrease in methane over time. <br />Previous investigations at the Golden Eagle Mine site included the initial installation of 28 monitor points in <br />March 1999 to determine the extent and concentrations of methane in the shallow subsurface soils. A second <br />investigation included the installation of 7 more monitoring points at the site in June 2000. These previous <br />investigations included reseazching the geology ofthe area, a surface methane survey, reseazchingneazbycoal <br />bed methane wells, and determining groundwater extraction in the area. The coal bed methane wells onsite <br />were plugged and abandoned in late 2000. <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 29.3 percent). Additionally, <br />average methane concentrations have decreased in the existing 35 points monitored since the last monitoring <br />report in 2004 (an average decrease from 38.4 to 32.3 percent). Vegetation was observed to be recovering <br />during the 2005 sampling event in azeas where methane concentrations had decreased. The effected azea of <br />vegetation during the 2000 survey was about 146 acres. The effected azea of vegetation during the 2005 <br />survey was about 32 acres, the same as in 2004. <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 airshaR 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 azea; however, water <br />monitoring studies indicate that the mine workings have been inundated, which should minimize any potental <br />for methane seepage to the surface. <br />There are no imminent hazards associated with the methane seepage other than stressed or dead vegetation. <br />Methane would only be a human or anima] health concern within a confined space, <br />292-MeN_Q 1.29.05).doc 11 <br />