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Memorandum to Harvey W. Curtis June 14, 2006 Page 3 As soon as permission is given, technicians from this firm plan to measure the depth to water in the Ansley pit, to confirm Mr. Rolf and Ms. Justus's observations. Depth to Ground Water in Nearby Well We have reviewed the State Engineer's Office well database for wells in the area and we identified one nearby well within the lateral limits of the outwash alluvium that the Applicant plans to mine. This well (Permit No. 209995) is located as shown on Objectors' Exhibit 7. The depth to ground water in this well ranges from 6 to 10 feet depending upon the season. Estimated Depth to Ground Water Using River Channel Elevation Objectors' Exhibit 8 shows the topographic contours (elevation of the land surface) and the Middle Fork of the South Platte River. Since the river is perennial (flows year round), the elevation of the river bottom is the elevation of the water table. Because the land surface contours are generally evenly spaced and generally perpendicular to the stream, the minimum elevation of the water table can be estimated by projecting the elevation of where the river crosses each contour to the west from the river, as shown on Objectors' Exhibit 8. The projected water table elevation can be subtracted from the interpolated land surface elevation to estimate the depth to ground water, as shown on Objectors' Exhibit 8. Using this approach, I estimate that the average annual depth to ground water is 10 to 14 feet along the northern boundary of the site, and 8 to 9 feet along the southern boundary and average about 9 feet. Considering the seasonal variation in the water table, the average depth to ground water during the spring and summer could be less than 7 to 9 feet. The actual water table elevation is likely somewhat higher because the water table needs to slope from the rechazge areas to the northwest to the river. This means that the depth to ground water is likely even less than that shown on Objectors' Exhibit 8. Summary Objectors' Exhibit 5 is a cross section from the Ansley gravel pit across the project site to water well Permit No. 209995 then to the river. It shows the land surface, the reported depth to water in the Ansley pit, the depth to water in the well, and our interpretation of the water table elevation based upon the river elevation. It also shows the likely seasonal water table fluctuation of four feet. The cross section uses all of the available evidence (except the Applicant's depth to water measurements that we believe are suspect) to show that the depth to ground water along the line of cross section on the project site is likely to range from 8 to 14 feet depending upon the season. LEONARD RICE ENGINEERS. INC.