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possibly parts of the lower aquifer as well, meet the classification for drinking water. <br /> Among the regulated parameters for drinking water, 5O4, CY, and F- and some metals in <br /> the lower aquifer commonly exceed drinking water standards. <br /> The upper aquifer is generally an underground source of drinking water(USDW), <br /> according to classifications under the Federal Safe Drinking Water Act, because it <br /> generally contains less than 10,000 mg/L TDS. Information in the permit application and <br /> in published literature show that parts of the lower aquifer has natural concentrations of <br /> several elements that would drinking water standards. (The published information <br /> includes mostly USGS publications on oil shale from the 1970s, some of which is <br /> referenced in the Permit Application.) The lower aquifer in the target area is under <br /> higher hydrostatic pressure than the upper aquifer, so the tendency for water movement is <br /> upwards, from the lower aquifer to the upper aquifer. Unless the lower aquifer remains <br /> isolated from the upper aquifer, there is a potential for the upper USDW aquifer to be <br /> cross-contaminated by toxic substances from the lower aquifer, due to mining-related <br /> activities. This leads to the determination that the operation should be classified a DMO. <br /> b. Based on general geological and geochemical principles, meteoric water in <br /> equilibrium with the rocks in the nahcolite zone should develop water quality similar to <br /> water in the dissolution zone. Contact with high temperature water such as proposed for <br /> the American Soda operation will hasten dissolution and water:rock equilibration. Thus <br /> it is likely that the composition of the process solutions will contain concentrations of <br /> elements that will exceed drinking water standards. This implies that there is a need to <br /> protect both the upper aquifer, the alluvial aquifer, and surface waters from <br /> contamination by the process solutions. If the process solutions indeed prove to be high <br /> in potentially toxic chemicals, this would lead to a determination that the operation <br /> should be classified a DMO. <br /> Based on item b, above, the operator should submit information on the trace element <br /> composition of the process solutions to help determine how the non-saline waters may need <br /> to be protected. <br /> 3. Analytical detection levels. In various places in the application and supporting documents <br /> the operator lists sampling and analytical parameters without indicating relevant detection <br /> levels. The operator is advised that for the proposed surface or groundwater sampling and <br /> analyses, the analyte list and the associated detection levels should consider the current and <br /> potential future beneficial uses of the water. For groundwater, the current and potential <br /> future beneficial uses include drinking water and agriculture. The surface waters in the region <br /> are classified for aquatic life, recreation, and agriculture uses. The operator should consult <br /> the most recent versions of WQCC's "Basic Standards and Methodologies for Surface <br /> Water" and "Basic Standards and Methodologies for Ground Water" for a complete <br /> parameters list and determine the appropriate detection levels. We understand that American <br /> Soda is in the process of submitting this information to the Division, and we will review it <br /> immediately upon receipt. <br /> 2 <br />