2014-11-21_PERMIT FILE - C1996084 (23)

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Rule 2.' Pernuts • estimated from this zone. This zone is also thought to represent a fractured sandstone that is in contact with the alluvium; therefore, during the installation of these wells this zone was cased off. Well screens at these locations were set in the consolidated sandstones overlying the coal. Primero Coal No increase in water flow was noted during drilling through the Primero coal at well locations MW-4, MW-5, and MW-6. All wells in this zone were set as per the aforementioned methodology. Underburden Underburden wells were installed in the sandstone encountered below the Primero coal at well sites MW-4, MW-5, and MW-6. With the exception of MW-5, no increase in flow was noted during the drilling of this zone. At MW-5 an increase of 5 gpm was estimated during the drilling of this well through this zone. Aquifer Characteristics and Water Quantity Recharge in the Raton Basin occurs principally in the form of precipitation. Studies by Howard • (1982) indicate that the recharge occurs in the area above 7500 MSL. Precipitation in this area is approximately 16.32 inches per year at 7200 feet MSL, and 14.94 inches per year at 6600 ft MSL. This illustrates that precipitation decreases substantially with a decrease in elevation. Precipitation in the area appears to be highest in the months of May, July, and August. Recharge appears to occur above the 7500 MSL elevation (Howard, 1982). Recharge also occurs in the form of influent streams. A major influence to regional recharge in the area is the presence of fractures in the rock. This fracturing is mainly associated with igneous intrusives, which have been encountered in the permit area. Discharge in the area is mainly through evapotranspiration (ET). According to Howard (1982) ET in the area is approximately 46.4 inches greater that precipitation (from Trinidad airport data). This amount of ET would create a large deficit in the permit area hydrologic budget. Other loss mechanisms include springs and gaining streams with springs in the area generally originating from either formational contacts (Poison Canyon/Raton), or confined coals. Regiortally, potentiometric surface gradient is thought to be to the east, and in the site area to the east-northeast. To develop this map, over two hundred wells were inventoried to determine location and elevation. This map indicates that the recharge to the aquifers in the site area occurs in the topographic highs and discharges to the Purgatoire River. • PERMIT rerUpnl3]. 194/ 2.04-10 (revised 4/21/97)