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Coal Methane Drainage Prged - Pane6 76-24 Wert E!k Mine with total dissolved solids concentrations between 43 and 2,300 mg/1. Sulfate, total dissolved solids (I'DS), and manganese occasionally exceed the drinking water standard. Bedrock contains ground water to a limited degree. The primary bedrock aquifers iri the area are the lower Cretaceous Burro Canyon and Dakota Sandstone Formations. Stratigraphically, these formations lie beneath several thousand feet of Mancos shale (below the Mesa Verde) and are hydrologically isolated from the Mesa Verde Formation. Ground water can also occur as isolated perched ground water occurrences. Perched ground water occurrences are associated with Gthologic units that are hydrologically connected to a recharge source, have sufficient permeability to store and transmit water, and aze underlain by a low permeabihty unit. The low permeability unit(s) limits downward water migration, and a small saturated zone builds up in the porous and permeable rock. Perched ground water occurrences aze typically relatively small, discontinuous, and have very limited storage volume. Underground water may also occur in the coal seams and associated stxaia, In the project area, the coal seams and assouated strata dip to the northeast. The upper units outcrop in the North Fotk Valley and are drained over a large area such that ground water occurrences in these units are rare. The D Seam is known to contain water on the north side of the North Foxk Valley. The D Seam and the overlying coalinterburden and overburden units are generally well-drained on the south side of the river in the vicinity of the project area. Ground water quality in the project area is highly variable dependent on recharge source, flow path, strata with which the water comes in contact, and discharge mechanism. Water quality for alluvial/colluvial ground water and perched ground water is commonly similar to surface water due to close surface and ground water interactions and limited residence times. Deeper perched ground water and any ground water associated with the coal seams that have been in contact with shales and mudstones may exhibit elevated levels of total dissolved solids. 3.1.1;5 Riparian Ripazian ecosystems typically occur along drainages where additional moisture {surface or ground water) is available. They are transitional areas between terrestrial upland habitat and aquatic habitat. Ripazian areas are not necessarily associated with wetlands, which generally have prolonged saturation of the soil. For purposes of this EA, however, the term "ripazian" will be used to include aquatic ecosystems (wetlands) as well as riparian ecosystems. In the project area, ripazian zones are usually narrow in width due to the steep topography and narrow drainage bottoms. There is no "typical" vegetation (for a riparian azea), vegetation varies with elevation and exposure. A spruce-fir community is common to riparian azeas at higher elevations and aspen may be co- dominant. Boxelder and narrow-leaf cottonwood may dominate riparian areas at lower elevations. Wildlife rely on ripazian and wetland areas for many aspects of their survival both day to day and over the long-term. These areas aze typically cooler than the surrounding hillslopes, aze important as sources of Food and protection, and attract a diverse composition of species, more so than other habitats. Additional discussion of riparian azeas relative to wildlife habitat and use is provided in Section 3.2.1. Riparian surveys conducted recently in the upper reaches of Sylvester Gulch provide informaton on representative site-specific riparian conditions for the project area (Greystone, Nov. 2001a and b). The identification and characterization of these "riparian" areas used protocol in a USFS guidance document (USFS, 1995). Additional information on possible riparian azeas was provided in the Threatened and Endangered Species (TES) survey for Panels 18 throagh 24 (Greystone, Oct. 2001b). Possible riparian azeas were identified by the presence of aspen, bracken ferns, and other EnvironmentolArrefrment IP16F/Mwv. GHG/EI/0..,ti/a/4?Fr (/SFf f/f/03J