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_Zg_ Probable Cumulative Hydrologic Consequences='Ground-Water Bedrock Ground Water Only limited amounts of ground water exist within the bedrock strata of the permit area. Because of the thin bedded nature of the stratigraphy, bedrock ground water only exists in small, laterally discontinuous, perched aquifers. The closest regional aquifer, the Trout Creek Sandstone, is located approximately 800 feet Below the mining area. Because of the thin interbedded nature of the strata, no impact on waters of the Trout Creek Sandstone aquifer is anticipated. For a more detailed description of ground water conditions, see Section 2.04.7 of the permit application. The applicant has stated that almost no use is made of ground water within the permit area. A few scattered wells and springs located along Good Spring Creek are used for stock watering. Many local residents haul their drinking water from Craig or Meeker because of the lack of dependable supply of ground water. Twv potential impacts to the bedrock ground water system in the mine area have been evaluated. Neither impact is expected to be significant. First, dewatering will occur as water from the perched aquifers discharge from the highwall. Because of low permeabiZities and unsaturate3 conditions, this phenomenon is only expected to occur in the irmnediate vicinity of the mine pit. Since there are no known users of this ground water in the vicinity of the mine, this impact is expectm to be insignificant. Experience at the mine site has shown that very little ground water is discharged from the highwall anyway. The pit has always been essentially dry. Any water that does discharge from the highwall seeps at such a Iow rate that it is rapidly consumed by evaporation. Second, t_he chemical quality of the water in the bedrock aquifers could become slightly degraded as a result of mining. As ground water slowly accumulates in the reclaimed spoils, it will leach salts from the broken up spoil material. This will increase the total dissolved solids (TDS) concentration of water. Because the perched aquifers exist above the elevation of both Taylor and Good Spring Creeks, all discharge occurs as springs or seeps in the canyon walls of these streams. Therefore, these perched aquifers are not connecter to any regional flow sytems.r All ground water discharge will either enter the alluvial systems of Taylor or Good Spring Creeks, or be evaporated from the canyon walls. The effects of this impact on any alluvial aquifers are further discussed below. In conclusion, any mining related impacts to the water of the bedrock aquifers is expected to be confined within the permit area. These impacts are not expected to be significant.