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Formation is coal barren and is 200 feet in thickness of alternating beds of mudstone <br />and sandstone. <br />Covering most of the topographic ridges in the Southfield mine area are a series of <br />Pleistocene boulder/colluvial/alluvial deposits. Most of the boulders consist of gneiss, <br />schist and sandstones derived from erosion and mass wasting of the Wet Mountain <br />uplift to the south and west. Depositional thicknesses range from 5 to 100 feet in <br />places near the mine site, with 20 feet recorded in the loadout area of the mine. <br />Hydrology <br />An extensive review of both the ground water and surface water hydrology can be <br />found in Section 2.04.7, 2.05.6 and 4.05 of the permit application. Below is a brief <br />summary of the ground and surface water issues at the Southfield Mine. Further <br />information on these items can be found in the "Probable Hydrologic Consequences" <br />Section B of this findings document. <br />Ground Water <br />Due to the extensive underground mining activities in the area, ground water baseline <br />information was difficult to obtain. Trends for ground water were established and have <br />been recorded since the mine opened as the Dorchester No.2 in the 1970's. Ground <br />water flow is difficult to predict based on the tendency for the ground water to flood old <br />workings in the area. Many residential wells have been drilled into the old abandoned <br />workings and provide residents with water. In the mine area, evaluation of groundwater <br />resources is based primarily on exploration drilling, records of ground water use, <br />information on regional groundwater characteristics, monitoring information, inflow into <br />underground workings at the Southfield Mine and historic information on abandoned <br />workings. <br />There are three categories of potential groundwater aquifers that occur in the permitted <br />area. These are 1) the Trinidad Sandstone, 2) coals of the Vermejo/Raton Formations <br />and 3) localized river alluvium. For a detailed analysis of each of these aquifers please <br />refer to the Probable Hydrologic Consequences of Section B. All ground water flow into <br />these three aquifers is the direct result of recharge collected from the Wet Mountains to <br />the west. The water flow is structurally controlled by the Chandler Syncline and runs <br />along the axis north to the Arkansas River where it discharges. <br />Surface Water <br />Surface water in the area flows from the Wet Mountains on the west to the plains on the <br />east then bends northward toward the Arkansas River valley. Most of the streams in <br />the area are ephemeral, flowing in response to snowmelt and intense rainfall events. <br />Much of the precipitation received is surficially absorbed into the colluvial material or is <br />lost to evaporation and transpiration. Local towns divert most of the remaining surface <br />waters from the mountain drainages for municipal use. The towns of Coal Creek, <br />Rockvale and Florence all have extensive water lines that utilize most of the water from <br />Page 7 of 36