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i 2.04.5 General Description of Hydrology and Geology <br />The mine is on the northern edge of the San Juan Basin which extends over thousands of <br />square miles in Colorado and New Mexico. The upper Cretaceous strata outcrops in <br />parts of the mine and locally dips 26 to 30 degrees to the southeast. These same strata <br />can be found several thousand feet deep in other parts of the basin. A surface geology <br />map of the Carbon Junction area has been included (See Map 4 -2). Oakridge has <br />provided a substantial amount of geological information in Exhibits F, G, and H of <br />Appendix 2.04. The reader is referred to these exhibits for a complete support knowledge <br />of the general and specific geology of the mine and permit area. <br />The mine permit area covers the upper reaches of potential recharge areas of basin strata. <br />Hydrology extrapolations indicate the main recharging for the aquifers occurs from the <br />Animas River which is up to 800 feet difference in elevation. Generally, minute <br />infiltration will occur in upland areas, such as the mine, and discharge to the level of the <br />river. The mine permit area occupies an infinitesimal area of potential infiltration of <br />water. The project will not significantly disrupt any flows or streams in the general <br />hydrologic area surrounding the mine because Carbon Junction Canyon flows only <br />intermittently. <br />While drilling exploration holes, on -site drillers and geologists identified inflows of water <br />in the discharge from drilling fluids. The amounts of water encountered were noted <br />along with the interval and strata from which the water apparently originated. <br />Field observation and testing during and subsequent to drilling indicate that water was <br />g g q g <br />encountered at the following locations: <br />1) Fractured coal seams, <br />2) Interfaces of coal and overburden, <br />3) Fractured zones <br />These observations also confirm that no additional water was encountered from the <br />sandstone members in the mine vicinity. More specifically, Holes 12B, 17B and 82 -5 <br />penetrated the Pictured Cliffs Sandstone which is of particular concern to the Division. <br />No water inflows was identified in the above mentioned holes. <br />The Pictured Cliffs Sandstone was examined as a potential aquifer. Consequently, <br />attempts have been made by the permittee to determine values relative to storativity (S) <br />and transmissivity (T), which are qualifications valuable in the determination of the <br />relative potential of an aquifer. See the information in Exhibit G for a detailed analysis <br />of the subject sandstone. The S and T values are particularly useful in assessing potential <br />of high -flow water wells. However, where low flows and non - homogeneous materials <br />are encountered, the T and S values are of little value, especially when extrapolated from <br />well tests. Well tests are often biased by fracture systems and faults, which give <br />erroneous T and S values. <br />Abridged Permit Document 4 -5 Feb 2008 <br />