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increase with depth and are at a maximum in the axial azeas of the Big and Round Bottom <br />Synclines. Artesian conditions aze developed in aquifers which are confined by overlying and <br />underlying strata with low permeabilities. Several of the wells drilled into the bedrock aquifers <br />within the study area exhibit artesian flows at the surface. The operator conducted aquifer tests to <br />determine the hydraulic properties of the aquifers (see permit application). <br />Bedrock Ground Water Quality. Ground water in the Trout Creek Sandstone and Williams Fork <br />Formation is predominantly calcium and sodium bicazbonate types. Water in contact with coals <br />is a calcium sulfate type and can contain fluoride, iron, manganese, selenium, and sulfate <br />concentrations in excess of U.S. Public Health Service drinking water standards, with the water <br />contained in the coals and thin discontinuous sandstones generally being of poorer quality than <br />that from the massive regional sandstone aquifers. <br />Alluvial Ground Water Occurrence. The Yampa River alluvium and the Williams Fork River <br />alluvium both contain alluvial ground water. These alluvial water-bearing units may store and <br />release water used by the overlying vegetation, and may sustain a component of baseflow to the <br />associated river systems. These alluvial units may provide recharge to rock aquifers and also are <br />recharged by rock aquifers within the ground water study area. <br />Alluvial Ground Water Quality. Alluvial water quality is variable, depending on the underlying <br />rock and source of alluvial material. Ground water from the Yampa River alluvium is primarily <br />sodium sulfate type. Dissolved solids average 4,586 mg/1 with a maximum measure of 8,810 <br />mg/1. Ground water for the Williams Fork alluvium is primazily of the sodium bicarbonate type. <br />Total dissolved solids average 1,009 milligrams per liter (mg/1) with a maximum measured <br />value of 1,510 mg/1. Maximum primary and secondary drinking water standards are exceeded in <br />both aquifers for many parameters including barium, cadmium, chloride, chromium, pH, sulfate, <br />and selenium. In addition, average concentration values for chloride, total dissolved solids, iron, <br />lead, manganese, and sulfate exceed EPA primary and secondary standards. <br />Natural Springs and Seeps. There are six springs within the pemut area and adjacent areas. <br />The North Spring, also referred to as the Lippazd No. 1, originates at the head of a small drainage <br />neaz its junction with old Highway 13 along the base of a thin Pleistocene or Quaternary gravel <br />that caps many terraces in the area. The East Spring flows from the base of a highway fill and <br />appears to be a man-made situation. The South Spring is located on a hillside west of the <br />Williams Fork River approximately one mite south of the No. 5 Mine portal where water <br />discharges from a sandstone lens within the Iles Formation. A small seep is found at the No. 9 <br />Mine face-up. This spring flows only in the spring and dries up in the summer. The Haxton <br />Spring originates in a weathered, brown-gray, very fine-grained sandstone. A pipe has been set <br />in the ground at the spring, but no flow has been observed. Aggregate flow from the springs is <br />less than 20 gpm. The springs that were surveyed do not appear to be discharge zones for any of <br />the regional bedrock aquifers and are not considered significant water sources. <br />Spoil Springs. Water seeps from the base of the old Williams Fork Strip Pit No. 1 and drains <br />into the Williams Fork River. Presumably the water percolates through the regraded spoils of the <br />pit. Flow has ranged between 4 gpm and 198 gpm. Total dissolved solids have averaged azound <br />1,OOOmg/1. <br />8 <br />