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The New Horizon Mine i produced coal from bath the upper and lower Dakota coal seams. The upper Dakota cval seam ranges in thickness from 1.6 feet to 3.3 feet and is separated from the lower Dakota seam by 7 to 1 I feet of interbedded sandstone and shale. The lower Dakota seam varies in thickness from S9 feet to 7.9 feet. The base of the tower Dakota coal is R3 feet above the top of the Burro Canyon Formation. The coal dips I" to 2° southwest and strikes N 2S°W to N 4S° W. The New Horizon Mine 2 primarily produces coal from the Lower Dakota caal seam and will utilize the Upper Dakota coal seam when the seam is thick enough and of sufficient quality. The tower Dakota coal seam at New Hvrizon Mine Z ranges in thickness from 4.2 feet to 6.9 feet and is 99 feet above the tap of the 13wro Canyon Farmation. The coal dips 4._5° SW along a strike of N 45° W $urfcrce Wearer The San Miguel River has its saurce in the San Juan Mauntains. These mountains are primarily composed of Tertiary volcanic rucks. Ioms et, al. (196Sa) has Shawn these waters to be of a calcium bicarbanate-sulfate type during high Clow periods. These waters contain less bicarbonate during low flows while the calcium and sulfate concentrations increase due to less dilution from snowmelt runoff. The 5<m Miguel River traverses [he interior portions of a basin that is chiefly underlain by Dakota Sandstones, the Morrison Formation and Maricos Shales. The lvlorrison Formation and Mancos Shale have the greatest potential fur influencing the river water chemistry. The San tiliguel River drains an area of 1,080 square miles. In addition, approxinr<uely 1S,SW acres of irrigated land lies between Placerville and Naturita. Colorado. It is estimated that 2.8 tons of Total Dissolved Solids (TDS) per acre are contributed ro the waters annually from this area. This results in increased levels of magnesium, potassium, sulfate and chloride. Water quality samples taken from the San Miguel River at Naturita, Colorado, have a weighted average of 316 milligreuns per liter (mgA} TDS. Specific conductance varies between 318 and 730 millimhos {mmhos). 1'he mean sodium adsorption ratio (SAR) is about 0.7 at Naturita. Water curves indicate that, 90 percent of the time, flow in this river exceeds 60 cubic feet per second (cfs). while flows exceed 1000 efs about 10 percent of the time. The mean discharge of the river is 3S 1 efs. San Miguel River waters .rre suitable fordo sti usage except at law tlow periods when sulfate levels are high. IvS~r 1 'L.Oy.'1 -~l ~ The Colorado Caoperative Ditch Company divers as much as 14S cfs of water from the San Miguel River approximately ten miles east of the town of Nucla. The main diversion ditch then flows westerly passing just north of the town of Nucla and then Flows not-thwestward passing~~ New Horizon Mine' Diversion ditches distribute water to mainly agricultural users in the area. Since the completion of the irrigation system fur this area in about 1910, these areas have been intensively reworked for irrigated agriculture. Additional uses include domestic, municipal and stuck pond consumption. The ew H rizon Mine 1 is loca[ed downslope from the main ditch in the gently sloped upland of Second Park. This is just north of Tuttle Dracv and is totally within its watershed. The Second Park Lateral Irrigation Ditch is in continuous operation fmm mid-April through tnid-October. White this water is primarily used fur irrigation, important secondary uses include maintaining water levels in stuck ponds and domestic cisterns. During the non-irrigation season the ditch is occasionally turned on to maintain the water levels in the stock ponds and cisterns,