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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. Thesesame 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 Appendices 4-2 and 4-3.The <br />reader is referred to these exhibitsfor a complete support knowledge of the general and <br />specificgeology 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 below the elevation of the Carbon Junction Mine. <br />Generally, minute infiltration will occur in upland areas, such as the mine, and discharge <br />to the level of the river. The mine permit area occupies an infinitesimal area of potential <br />infiltration of water. The project will not significantly disrupt any flows or streams in the <br />general hydrologic area surrounding the mine because Carbon Junction Canyon flows <br />only 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 />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 from the Pictured Cliffs Sandstone wereidentified in the above <br />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 Appendix 4-3afor a detailed <br />analysis of the subject sandstone. The S and T values are particularly useful in assessing <br />potential of high-flow water wells. However, where low flows and non-homogeneous <br />materials are encountered, the T and S values are of little value, especially when <br />extrapolated from well tests. Well tests are often biased by fracture systems and faults, <br />which give erroneous T and S values. <br />Abridged Permit Document4-5Permit Renewal RN04 4/2014 <br />