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7. Facilities Evaluation <br />Maps and drawings describing the facility layout are included in Figure 2. <br />• The berm at the top of the waste rock pile will prevent water from running down the face of the <br />pile (except for the precipitation that falls directly on the face slope). This will reduce erosion of <br />the pile as well as reducing the amount of runoff leaving the site. The water bar designed for <br />the access road will minimize the amount of water that runs onto the waste rock pile surface <br />and the amount that can contact the ore stockpile. <br />• The liner, which will be installed before any ore stockpile is constructed, will prevent leachate <br />from seeping into the underlying waste rock pile. <br />8. Groundwater Information <br />Figure 3 shows the regional geology of the Hamm Canyon area. Surface topography, including drainages, <br />is also shown on this map. Figure 4 shows is a cross - section of the area showing stratigraphic section of <br />the geologic formations near the mine area. There are no known nearby springs or water wells. The <br />map shows ephemeral stream channels and other water features from the mine area to the confluence <br />of Hamm Canyon drainage with Big Gypsum Creek and the eventual confluence with the Dolores River. <br />The River is 6.1 miles downstream from the mine site. The strata that are potential aquifers within 2 <br />miles of the site are comprised of the following in the order of their occurrence: <br />- Sandstone /conglomerates of the Burro Canyon Formation, (perched water above and to the north and <br />east of the mine). It is 190 -240 feet thick. <br />- In certain locations, the sandstone /conglomerates of the Brushy Basin Member of the Morrison <br />Formation contain perched water. The Brushy Basin is well exposed on the slope above the mine site. <br />No sandstone units of significance outcrop there and those found in historic drill holes near the mine do <br />not contain water. The bulk of the Brushy Basin is bentonitic mudstone which is very effective as an <br />aquitard. This member of the Morrison is 350 -430 feet thick. <br />- Sandstones of the Salt Wash Member of the Morrison Formation may contain perched water at a few <br />locations in the region; however, there are no known groundwater occurrences at or near the Sego <br />Mine. The Mine site is located in the upper sandstone unit of the Salt Wash and is dry. The small adits <br />of the Lookout Mine Y4 mile to the south are in the lower sandstone units of the Salt Wash and are also <br />dry. The Salt Wash crops out for many miles both northwest and southeast of the mine site. No springs <br />or seeps are known to exist along this outcrop band. The Salt Wash is 320 -380 feet thick in the area. <br />- Sandy shale and mudstone of the Summerville Formation (aquitard with no aquifers)is about 100 feet <br />thick. <br />5 <br />