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Memorandum to Harvey W. Curtis June 14, 2006 Page 2 measurements taken over a period of days until the. water level no longer changed. It does not appeaz that the Applicant made multiple measurements, so the reported water level measurements are suspect. SEASONAL VARIATION IN WATER TABLE NOT EVALUATED The depth to ground water probably fluctuates seasonally, with winter being the lowest and spring being the highest. The Welt Construction and Test Report for a water well (Permit No. 209995) neaz the proposed Allen Pit shows that the depth to water in mid-May 1999 was 10 feet. The Pump Installation Report for the same well shows that the depth to water was 6 feet in late June 1999. Because the water table rose 4 feet from mid spring to early summer, I conclude that the seasonal variation in the water table in the area of the site is probably on the order of 4 or more feet. The Applicant's one reported measurement of the depth to ground water in each of the three monitoring wells on the site is insufficient to evaluate the seasonal fluctuation. To properly determine the seasonal variation requires monthly measurements made over a period including at ]east two seasons with high water tables, e.g., June in two consecutive years DEPTH TO WATER MEASUREMENTS OF WELLS LOCATED OUTSIDE OF THE OUTWASH ALLUVIUM ARE NOT REPRESENTATIVE Objectors' Exhibit 9 shows the wells that the Applicant used in his application to indicate that the depth to ground water on the site was greater than I O feet. These wells are all completed into bedrock that aze hydraulically different and, to a significant degree, sepazated from the outwash alluvium that the Applicant proposes to mine. Consequently, they cannot be used to estimate the depth to ground water beneath the prof ect site. OUR OPINION OF THE DEPTH TO GROUND WATER Our estimate of the average annual depth water is based upon three lines of evidence, as follows: 1) The observed depth to ground water in the Ansley gravel pit to the northwest, 2) The depth to ground water reported for a nearby water well located within the limits of the outwash alluvium, and 3) Interpretation of the depth to ground water using the elevation of the Middle Fork of the South Platte River located east of the site. Depth to Water Measurements, Ansley Gravel Pit Kent Rolf and Heather Justus of this fum estimate the depth to water is approximately 20 feet at the north end of the Ansley gravel pit located northwest of the project site, as shown on Objectors' Exhibit 7. They also report the depth to be approximately 10 feet at the south end of the Ansley pit, also as shown on Objectors' Exhibit 7. LEONARD RICE ENGINEERS. INC.