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July 30, 2010 9 of 24 <br />test data from the Schwartzwalder mine are at the lower end of the ranges cited by Freeze and <br />Cherry. <br />The Division's "evidence" that fractured rock can have hydraulic conductivities 100,000 times <br />greater than the packer test results is based on textbooks and other physical locations that may <br />have no relevance to rocks at the Schwartzwalder Mine. Cotter has a clear understanding of site- <br />specific conditions, while the Division relies on textbooks, speculation, and general theory to <br />make a broad argument about rock hydraulic conductivities. <br />The packer tests were conducted in holes selected to represent the various rock types in the mine. <br />Significant resources were expended, and every attempt was made to collect valid scientific data <br />that would contribute toward a thorough understanding of this site. Excluding the test that had <br />leakage around the packer, the highest observed hydraulic conductivity from the packer tests was <br />1 x 10-5 cm/sec. The test zone had a width greater than 550 feet and it is probable that a few <br />fractures within the test interval were responsible for the observed permeability. If the same test <br />data is used to evaluate the hydraulic conductivity of a much narrower fractured zone, for example <br />10 feet, the permeability of the fractured interval would be calculated to be 6 x 10-4 cm/sec. If a 1- <br />foot wide fracture zone was responsible for the observed flow, the permeability of the zone would <br />be 6 x 10"3 cm/sec. This example demonstrates that the numerical value assigned to hydraulic <br />conductivity is a function of the width of the zone that is assumed to contribute to flow. The <br />majority of the packer tests indicated very low permeability for the rock mass (on the order of 10"7 <br />cm/sec), or no observable permeability within the limits of the testing apparatus (i.e less than 1 x <br />10"7 cm/sec). Thus, the packer tests were assigned a permeability of < 1 x 10"7 cm/sec. The actual <br />value could be significantly lower. The calculation of geometric mean hydraulic conductivity for <br />all 22 packer tests used this upper limit (1 x 10"7 cm/sec) for 8 of the 22 tests. No attempt was <br />made to estimate the actual (lower) hydraulic conductivity for use in calculating the geometric <br />mean. <br />In summary, the packer test data are representative of the overwhelming majority of the rock mass <br />at the Schwartzwalder mine and indicate that the rocks have a very low permeability on the order <br />of 10-7 cm/sec or lower. Narrowly defined fracture zones have permeability several orders of <br />magnitude greater and are responsible for virtually all the observed steady state inflow to the mine <br />of 190 gpm. If the rock mass is considered as an equivalent porous media on a mine scale, inflow <br />calculations presented in Table 1 and in the EPP suggest the bulk permeability of the rock is about <br />2.9 x 10"' cm/sec. Although the packer test data may not capture small-scale features or individual <br />fractures that dominate inflow to the mine, measurements of steady-state inflow to the mine <br />combined with observation of where the inflows occurred provide a reliable method that can be <br />used to evaluate the "entire hydrogeological system."