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>� Ground water in the alluvium slowly migrates down gradient at a rate of about 90 feet per year in the area beyond the "no change" line. We do not expect this flow rate to increase as a result of j the dewatering. It is possible that if the ground water upgradient is somehow contaminated, the normal migration of ground water may carry those contaminants to existing wells . However, we do not at this time know of any contamination. In any event, because the wells are beyond the "no change" line, the rate of migration of any contaminants will not increase as a result of dewatering. The methodology used to calculate increases in depth to water was confirmed by comparison of the actual versus calculated increase for the Deepe Farm well. This well is located about 390 feet from the dewatering trench for Stage 1 and is within the area where the depth to water has increased due to dewatering. The calculated increase of 2 . 38 feet agrees well with the observed increase of about 2-3 feet. In the case of Stage 4, the calculated increased depth to water and the distance from the trench to the "no change" line are the likely maximums . This is because there are two unlined irrigation ditches that flow generally parallel to the planned dewatering trench between the trench and the nearest wells . Seepage from the ditches recharges the water table and will likely maintain the elevation of the water table in the vicinity of the ditches. The distance to the "no change" line for Stage 4 is slightly greater than the 300 feet distance presented in the original Deepe Pit Application. For Stage 6 the distance is -from slightly less to slightly greater than 300 feet. The increase and decrease is due to the use of site specific data for Stages 4 and 6 rather than average data as was used in the original Application. 3 �[� Leonard Rice Consulting Water Engineers,Inc.