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the subject area, surface subsidence effects have been minimal. This actual "on-the-ground" experience <br />provides a reasonable perspective on the potential for any continuing or future surface subsidence effects, <br />and is a direct reflection of the practical mine subsidence control measures (advance room and pillar with <br />• retention of support pillars on retreat), overburden depth (typically 400' to over 1,000'), and competency <br />of the overlying lithology (massive sandstone beds). Mine flooding should not have a significant adverse <br />effect on mine subsidence, since roof, floor, and pillar spalling are generally worst when mine workings <br />are exposed to the air and subject to ongoing oxidation. Mine flooding typically reduces ongoing <br />oxidation. <br />• <br />C~ <br />Liability Release Response - No. 3 4 12/07/05 <br />