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shows that fractures behave as capillary barriers that restrict the movement of water in the unsaturated zone. Direct evidence of this unsaturated zone process is provided by the miue itself that intersects the fault but shows no evidence of water movement along the fault. We can properly use the same rationale as that identified above for the JD-6 Mine for estimating groundwater levels underlying the mine's waste pile. Using the alluvial well in the Paradox valley, the elevation of JD-8 is 6470 feet and located approximately 3 miles from the alluvia] we]] in the Paradox valley. Using a similar hydraulic o'adient and the elevation of the mine, groundwater levels underlying the site may exceed a thousand feet. The Cotter migration pathway computer analysis shows that constituents of concern reach only 400 feet in depth at concentrations of one millionth of initial concenh'ations after 1,000 years. The net result is that the plume at the defined concentrations fails to reach the groundwater -even after 1,000 years. A monitoring well would have to be drilled hundreds of feet beyond the extent of any potential plume and would provide little useful information regarding potential envirotunental impacts. E. Comuuter ModelinH Results Suaport Cotter's Request for Exemption. The computer model submitted by Cotter's consultant, Peter Kearl of GeoScience Services ("GeoScience"), adequately demonstrates the lack of impacts from Cotter's operations. Indeed, there is precedent for the Division to allow use of computer modeling which demonstrates, among other things, that dilution of contaminants with fresh water or ground water will result in compliance with ground water numeric protection levels. if dilution is selected as a means of meeting groundwater numeric protection levels, the operator is allowed to construct or use a computer model showing that dilution rates can be expected if rain or snow melts drives pollutants fi'om the ruck piles n~to local ground water. 7