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• Elevation Map," in the permit application was prepared in response to a request by the CMIRD. The groundwater data collected Co date at the Mt. Gunnison property strongly suggest that this type of map is not an accurate representation of the actual hydrogeological situation in this area. This was the reason that such a map was not included in the original submittal. The exhibit was not called a "water table" or "potentiometric" map as this implies that there is a continuous zone of saturation that may be defined by contours. The interpretation of the groundwater system is that it is discontinuous and is strongly controlled by topography and bedrock fracturing, particularly at shallow depths. Conventional representations of groundwater flow are not very reliable in situations where perched aquifer conditions and fracture control of shallow groundwater flow exist. The well data at the Mt Gunnison property indicate that the groundwater conditions in the Barren Member cannot be represented by a single potentiometric surface. Water levels in wells vary significantly with depth of completion within the Barren Member. For example, wells SOM 38-H- 2 and SOM 38-H-3 completed at a depth interval of between 700 and 940 feet have water elevations at 7100-7120 feet while the SOM 38-H-1 well at the same location completed between 430 and 580 feet has a water level elevation at 7450-7470 feet. The data from these bedrock wells indicate a water level difference of 330-370 feet between the completion intervals. Furthermore, the water levels in the wells are within or slightly above the screened interval within the wells indicating very little pressure head. A similar situation exists at the SOM 45-H-1 and SOM 45-H-2 site. At these locations, the low pressure heads and the vertical hydraulic gradient close • to or greater than unity, indicate very limited vertical hydrologic communication. This is consistent with the interpretation of perched aquifer conditions over the permit area. Most springs in the area originate from local recharge and shallow sub- surface flow through fractured bedrock or colluvium. Flows are consequent- ly seasonal and most springs only flow fora few months following the spring runoff period. There is no evidence to suggest that any of the mapped springs originate from bedrock formations at depth due to high artesian pressures. Upward hydraulic gradients have not been observed at any location on the property. Consequently, the elevation of the land surface at a spring does represent the elevation of a saturated groundwater zone at that Location. In many cases this saturated zone may be of limited extent and may be perched above bedrock zones which are unsaturated due to the existence of an intervening, relatively unfractured bedrock unit having a lower permeability. A water table map drawn using spring elevations will not have the same contours as the land surface. The contours would only intersect at the spring locations. Typically, the water table configura- tion is a subdued reflection of the land surface. The location of the groundwater divide with respect to the shallowest saturated groundwater zones is well defined by the spring locations. Additional monitoring wells would not significantly improve the definition of the divide or the interpretation of the groundwater system. 4. Pages 2-415 to 2-479 contain ground water monitoring data as recent as 1980. Please include monitoring data that is more recent. • V-2