Laserfiche WebLink
Since no water contribution was found in the Pictured Cliffs Sandstone while drilling, T <br />and S values cannot be determined from well testing. However, porosity and <br />permeability can be accurately determined by laboratory analyses. A detailed lab <br />analysis of a core from the top of the Pictured Cliffs Sandstone has been included as <br />Appendix 4-3a. <br />The Pictured Cliffs Sandstone has an effective porosity of 14.07 percent and an effective <br />permeability of zero. Permeability was analyzed with respect to water, air, kerosene and <br />hydrogen (Appendix 4-3a).Also, the Pictured Cliffs Sandstone is dry downdip of the <br />mine next to the Animas River indicating no general flow in the sandstone toward the <br />river. The one spring noted on revised Map 4-3(Mine Hydrology Map) is from a <br />fractured system in the exposed sandstone, basedon a visual observation. <br />Substantial water was encountered when drilling hole 82-4 from the interval 383 feet to <br />390 feet. As can be seen from the attached electrical logs, this strata (See Log 10B.) is <br />not a sandstone but laminated sandy shale. By reference to logs on Holes 10B and 82-1, <br />one can see that the water is not available in other drill holes at this interval. <br />Consequently, the water is likely to be flowing from a fracture system. <br />Also, water is encountered in the coals and coal-overburden interfaces. Water <br />encountered in drill Holes 17B and 82-5 are representative of the groundwater found in <br />the coals and interfaces. Holes 17B and 82-5 are monitored for water levels and quality; <br />the results of which are included in the reporting for thispermit. Ground-water <br />measurements have been shown in Appendices 4-3 and 4-3a. <br />In summary, field observation and laboratory analyses indicate the following: <br />1)Water of pumpable quantity has been encountered in isolated drill holes and is <br />found in fracturesystems or lenticular siltstones. These systems are perched and are <br />expected to bleed down with time when pumped because of the lenticularity of the strata. <br />2)Water wasencountered in the coal and interfaces. Typically, the flows were1 to <br />3 gpm and are of quality shown in submitted 1ab analyses. <br />3)No water is found in the Pictured Cliffs Sandstone. The absence of permeability, <br />which is a transmissivity relationship, indicates that no definable water will infiltrate, <br />percolate or invade the sandstone from the mining operation. If water is available in the <br />open pores (14% porosity), it is definitely immobile. <br />4)There are no aquifers in the permit area or the areas adjacent to the permit area. <br />Refer to electric logs and strata identification. <br />Pit inflows were projected to be 100 to 200 gpm in the early pit development based upon <br />very generalized extrapolations from drill hole data. This contribution is comprised of 20 <br />to 30 gpm from coal seams and the remainder from fracture systems.During mining the <br />Abridged Permit Document4-6Permit Renewal RN04 4/2014 <br />