2016-02-03_PERMIT FILE - C1981038 (2)

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52.04 APPLICATION FOR PERMIT FOR SIIRFACE OR UNDERGROUND MINING ACTIVITIES -- • MINIMUM REQUIREMENTS FOR INFORMATION ON ENVIRONMENTAL RESOURCES. 2.04,7 Hydrology Description. (1) (b) (Cont'd,) cottonwoods, alders, boxelders, and willows occurs along the length of the North Fork, but is not common in the vicinity of Paonia due to the development of the river bank. Little riparian vegetation occurs on other colluvial/alluvial deposits within and adjacent to the permit area. Additional information is found in Basin Descriptions, Volume 5. Mesaverde Formation - Groundwater Below the "D" Seam Groundwater occurrences within the Mesaverde Formation have been interpreted from neutron geophysical logs run during the exploration drilling process (refer to Map 10-1 and Ground Water Appendix, Volume 4) and from pre- vious underground monitoring at the Orchard Valley Mine. In addition, water quality samples were obtained and static water levels or potentiometric elevation da- ta were noted. From the available information, the most laterally continuous saturated horizon within the • Mesaverde is stratigraphically between the Rollins Sandstone member and the Upper "C" coal seam, typically 40 to 150 ft. below the "D" coal seam. Isolated, dis- continuous saturated strata occur as perched horizons locally above the "D" coal seam (refer to Map 10-1), The "D" coal seam is located 175 to 200 ft . above the Rollins Sandstone and is separated from the Rollins Sandstone by sandstones, siltstones, clays, and coal seams. Observations during drilling of the exploration boreholes and measurements of water levels in deep mon- itoring wells indicate that the sandstone strata below the "D" seam are mostly saturated. This sandstone strata is considered to be the most laterally continu- ous and saturated water bearing horizon within the Me- saverde Formation in the permit area. Although no data for permeability or transmissivity of the saturated part of the coal bearing member of the Mesaverde Forma- tion are available within the permit area, the experi- ence by others (Brooks, 1983) indicates that the Mesa- verde Formation transmits little water. 'Die primary (granular) permeability is low due to the lithologic composition of the sandstone and the secondary (frac- ture) permeability is not well developed. Extensive . Revised 12/26/84 Revised 10/01/87 33