2015-02-27_REPORT - M1982020 (3)

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weathering to produce a more level and even surface than the adjacent metasedimentary rocks. Review of the results of the geologic mapping of both the surface and underground within the mine, all the groundwater located below the mine, the processing facilities, and tailings ponds would be expected to be captured to in the northwest - trending structure. The groundwater flows would follow the dyke and any other sub - parallel bedding and foliation planes associated with this zone of weakness within the metasediments. Once captured, the groundwater flow would ultimately be channeled toward the bottom of the gulch and to the Lucky Strike Mill Spring. There are no other known geologic structures that would affect hydrology within the permit area. The flow velocity (permeability) of water across the bedding planes of the metasediments is currently estimated to be no greater than 10-6 centimeters per second over any distance of more than a few feet; this number being based on testing of similar rock under similar conditions. The flows of the Lucky Strike Mill Spring have been observed for many years, but no formally recorded information has been found to exist. However, past workers indicate that the spring flow has decreased within a few days after pumping of the water out of the mine, with the period stated to be from 3 to 5 days. Calculation of a flow velocity using this time period results in a velocity (permeability) of 7 X 10 "2 centimeters per second, which corresponds with the times given, and indicates a travel time between the mine and spring of a little over a week. Based on the data collected, this value appears reasonable and matches the observations of people familiar with the spring. Thus, the conclusion generated is that the spring is a good indicator of groundwater quality for the area below the mine and processing area.