Laserfiche WebLink
r~ <br />C~ <br />retains no liability for reclamation of the Santa Fe Loadouts. <br />III. Hydrologic Balance -Rule 4.05 <br />Regional baseline groundwater hydrology information is presented in <br />Section 2.04.7(d) of the permit application. Three water-bearing lithologic units <br />have been identified in the permit area and adjacent areas. These are the <br />Raton Formation, Vermejo Formation, and Trinidad Sandstone (youngest to <br />oldest). <br />According to the U.S. Geological Survey, the Trinidad Sandstone is the most <br />significant aquifer of regional extent in the area, consisting of tightly cemented <br />sandstone. It has been reported to yield from 0.5 to 5.0 GPM from wells in the <br />Raton Basin. Water quality is poor to fair and use is primarily for livestock <br />watering, limited domestic purposes, and irrigation. The coefficient of <br />permeability is estimated to be less than one darcy. The Trinidad sandstone is <br />located approximately 80 feet stratigraphically below the coal seam to be mined. <br />The Raton Formation overlies the Vermejo Formation. The Sopris Seam, the <br />uppermost seam of the Vermejo Formation, is generally regarded as the <br />formational contact. <br />The Vermejo Formation overlies the Trinidad Sandstone and contains the coal <br />seam of interest at Rimrock. The Vermejo Formation consists mainly of <br />sandstone and coal lenses interbedded with shale. It has a reported ground <br />water yield of 0.5 to 2.0 GPM. The water quality is generally rated as poor and <br />unsuitable for human consumption. The water is mainly used for livestock and <br />irrigation. This assertion was supported by water quality data supplied to the <br />Colorado Department of Health by the permittee during its NPDES permit <br />application. <br />The regional hydrologic study performed by the U.S. Geological Survey <br />(USGS WRI 83-132) treats the Trinidad Sandstone, the Vermejo and the <br />Raton Formations together as one bedrock aquifer. The Raton Formation, <br />which overlies the Vermejo Formation and the coal seam to be mined, is not a <br />water-bearing unit at the site. This was demonstrated by the exploratory drilling <br />performed by the applicant which showed no signs of water from the Formation. <br />Because of their permeability and proximity to the coal seam to be mined, the <br />Trinidad and Vermejo Formations are the water-bearing formations of concern <br />with respect to mining and reclamation impacts. <br />A reconnaissance level survey of springs, seeps and mine discharges within <br />one mile of the permit area was conducted. One seep (the Montoya seep) and <br />two mine discharges from old mine workings were identified in the northwest and <br />southeast areas of the permit area. Water quality and flow rates were measured <br />for the months of April and May, 1988. The Montoya seep, which originates <br />from the previously undermined area, had insufficient volume to evaluate. The <br />13 <br />