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Change in methane concentration <br />^ C02 <br />^ Oxygen <br />^ Methane <br />Methane <br />Oxygen <br />;02 <br />-'ea M <br />n'0~e eaap Mean. <br />h"e~i osfw posy <br />seal airs ~o <br />eat ~~a9 <br />Conclusion <br />bed <br />d methane ~s liberated by the dewatering of the host rocks. Some dewatering occurred when the mine <br />eyed the fault ~n the second right development entry. Oewatenng may have also occurred to some <br />om drilling activities. Local experience also demonstrates that methane can move along well bores <br />i the well annulus area to the surface, both after completion and after abandonment Improper well <br />ion is documented in well 28-10, although the well is now believed to be properly cemented and <br />led. Operational pumping occurred during mining (dewatering) followed by flooding of the mine <br />flowing mine closure. Water ~s now measured at 6781 feet above MSL (Nov. 2002) some 25 feet <br />ie floor of the 2`4 right development entry, the source of the majority of the mine methane and water <br />rhus. rt ~s reasonable to assume that the elim~naUOn of These pathways and sources of methane in the <br />tce through well sealing and mine flooding has reduced or eliminated the seepage of methane to the <br />soils in the affected area. The data supports this conclusion. <br />Recommendations <br />The Division of Minerals and Geology recommends that monitoring be continued at a minimal frequency Through <br />the 2003 growing season. If continued reduction of methane occurs and soil oxygen content remains elevated <br />or increases. vegetation growth ~s likely to resume. Reseeding of affected areas. at a minimum on a test basis, <br />would be helpful to determine if the area has returned to normal conditions. Any work in the Toupal pasture <br />area should be based on the availability of water and coordination with R1r. Toupal. <br />