2011-05-18_PERMIT FILE - C1981012 (2)

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Probable Hydrologic Consequences New Elk Mine 13 Water quality in the Raton Formation can be highly variable and range from potable in sandstone beds that are locally recharged by infiltration of meteoric water to non - potable in coal seams and deeper beds distal to areas of recharge. 3.2.3 Vermejo Aquifer Based on completion reports for 888 CBM wells, the thickness of the Vermejo in the Northern Raton Basin ranges from 65 to 590 feet (Watts, 2006a). The Vermejo Formation contains as many as 15 coal beds that are generally 3 to 6 feet thick. The total coal thickness of the formation ranges from 5 to 45 feet (Clarke and Turner, 2002). Coal beds in the Vermejo Formation generally are thicker, more regular in thickness, and more laterally persistent (1,000 to 3,000 ft) than those in the Raton Formation. The contact of the Vermejo Formation with the underlying Trinidad Sandstone is conformable (Wood et al., 1956). Watts (2006a) describes the Vermejo formation as a heterogeneous and anisotropic aquifer, but because of the lateral persistence and thickness of the coal beds, it is likely to be less heterogeneous than the Raton Aquifer. CGS estimates that transmissivities in the Raton - Vermejo Aquifer range from about 0.02 to 79 ft /day. Water quality in the Vermejo Formation can be highly variable and range from potable in sandstone beds that are locally recharged by infiltration of meteoric water to non - potable in coal seams and deeper beds distal to areas of recharge. 4. SURFACE WATER HYDROLOGY The New Elk Mine is located on the Middle Fork of the Purgatoire River, about 1.5 miles upstream of the confluence of the North Fork. Most surface facilities of the mine are adjacent to the Purgatoire River (Plate 1); underground mining occurred under and to the north and south of the Purgatoire River in the Picketwire Valley (Figure 1). The Purgatoire River is the primary stream drainage in the area of the mine. The headwaters of the Purgatoire are located on the eastern slope of the Sangre de Cristo Mountain Range west of the mine area. The general direction of stream flow is easterly to the confluence with the Arkansas River. Apache Canyon and Ciruela Canyon are the principal tributaries of the Purgatoire River that are within the permit area. Apache Canyon drains a watershed of approximately 7,264 acres. Ciruela Canyon drains a watershed of approximately 1,966 acres within the permit boundary. Surface water monitoring programs have been conducted since February 1984 to assess the effects of past, present, and future mining operations on surface water quality and quantity. These programs provide information to the operators of the facilities as well as to regulatory agencies. The results of the surface water monitoring are contained in Annual Hydrologic Reports ( Picketwire Processing 2002 -2007; New Elk Coal Company, 2008 and 2009). Surface water data for the New Elk Mine are available from two stations on the Purgatoire River (PRS -1 and PRS -4), three springs in Apache Canyon, one spring in the Middle Fork of the Purgatoire River, and nine ponds and direct drainages (some which are now terminated and /or reclaimed). Stream flow data for the Purgatoire River are also available from USGS gauging stations at Stonewall and Madrid. 4.1 Purgatoire River Stream flow data for the Purgatoire River are available from two USGS gauging stations. Station 07124050 is located on the Middle Fork of the Purgatoire River near Stonewall, approximately four miles upstream from the New Elk Mine. It was operated from October 1978 to September 1981 and is not currently active. Station 07124200 at Madrid is located approximately 18 miles downstream from the New Elk Mine and has been monitored since 1972. It is still in operation. The size of the drainage area above the Stonewall station is approximately 52.1 square miles. There are some diversions for irrigation above 4164A.110421 Whetstone Associates TV GA QtAl D VIA AI M1 1