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<br />2i The strike /dip of the Mancos Shale is such that the deepest portion of the <br />gravel deposit (some 60+ feet) is in Phase 1 and becomes shallower towards <br />Phase 5. Again, the angle of bedrock indicates that the concern over exposure <br />and impact to groundwater is greatly diminished by the fact that the deeper <br />portions of the gravel deposit is going to be mined first. <br />3) A site inspection by Mr. Lewicki documented no evidence of groundwater exiting <br />slopes via seeps or springs along the eastern edge of the mesa below <br />approximately forty (40) feet from the crest. The observations included photos <br />of adjacent pit highwalls, photos of undisturbed slopes showing no phreatophyte <br />vegetation or salt deposits from evaporation indicating natural exposure of <br />groundwater. The photos of the pit wall were taken in December, so there is an <br />issue of no active irrigation at the time, but staff observations in July support the <br />assertion that no groundwater was exposed to approximately 40 feet in depth. <br />The lack of phreatophyte indicator vegetation or salt deposits along slopes and <br />noted presence of such vegetation at the toe of the slopes was not presented as <br />evidence to support the depth to water on behalf of the applicant. This <br />observation is key to noting natural and historic groundwater levels. <br />41 Analysis of groundwater interception at surrounding pits mining the same gravel <br />deposit show that, at least to the proposed depth of mining to thirteen (13) feet, <br />there appears to be no indication of exposure of groundwater. Several <br />references were made to these pits, but nothing verbally or written was <br />presented to show collaborative evidence of the overall groundwater depth on <br />the mesa. The analysis indicates that the original staff proposed 20 feet was <br />conservative and the proposed change to 13 feet even more so. <br />5) Exhibit 1 Map showing surrounding area elevations, geological features, currently <br />permitted MLRB sites, and known depths of excavation without encountering <br />groundwater. The map ties several aspects of known information with additional <br />data supplied by Lewicki that clarifies the relationship of topography, geology <br />and known hydrology of the entire area. This information might address some of <br />the Board's concerns over the possibility of accidental exposure and impacts to <br />the prevailing groundwater table during the initial first year of mining. <br />Overall, the submission of the Lewicki report in conjunction with existing evidence already <br />presented, maybe sufficient grounds to review the "no mining stipulation". Also, <br />modification to the stipulation to allow mining down to 13 feet may bring the overall <br />decision in line with other mining activities approved by the Board at similar sites. <br />Sincerely, <br />G. Russell Means <br />Environmental Protection Specialist <br />2 <br />