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Permeability between boreholes may be enhanced using hydraulic fracture or • blasting agents where multiple borehole techniques are employed. Single hole techniques using steam injection have been demonstrated by Shell (see Prats et al. 1977). Recovery of nahcolite by solution mining as proposed by American Soda has the potential to improve the recovery of oil shale by a true in situ process. In fact, recovery of the oil from oil shale below the Dissolution Surface may not be possible by any means other than an in situ process that includes nahcolite recovery as proposed by American Soda. The operational pressures in the solution cavity (300 to 700 psig at the wellhead) would be below lithostatic pressure. As a result, significant fracturing of the formation hosting the solution mining interval is not expected. Impacts to geology from the proposed pipelines would be minimal because the pipes will be buried only 3 feet deep. The impacts to geology along the majority of the pipeline route would be limited to minor subsurface disturbances where rock would be excavated, crushed, and re-applied as base material for the pipes. The only areas of potential concern from a geological standpoint are those areas with significantly steep slopes, particularly Davis Point. At Davis Point, bedrock exposed at the ground surface would likely be impacted in an attempt to create both an adequate base and a direct route for the pipes. In addition, pipeline construction in areas of very steep slopes and talus slopes could result in some destabilization of slope materials. However, the final detailed pipeline routing will avoid areas that have the greatest potential for creating unstable slopes wherever possible. The Parachute Site would only involve construction of surface facilities and, at the preferred site, only minor excavations for structural footers would be required. Consequently, no impacts to geological resources are anticipated at the Parachute Site. 8.1.2 Soils Impacts to soils under the commercial mine plan would occur to all of the soil types described in Section 7.2.4. Impacts to soils at the Piceance Site would be the greatest due to the extent of mining that would occur over the life of the operations. The extent of these impacts would be related directly to the mine development sequence. Impacts would occur primarily in the form of road building, facilities construction, and well drilling. Impacts from solution mining activities would occur almost entirely to Rentsac channery loam soils. As described in Section 7.2.4, this soil series consists of shallow, well-drained soils, with a high percentage of rock fragments within the various soil horizons. These soils have rapid permeability, very low available • water-holding capacity, and a moderate erosion hazard (SCS 1982). Rentsac channery loams have poor potential for development and as source material due to American Soda, L.L.P. 8_5 Commeraal Mine Plan August 18, 1998