2008-05-01_REVISION - M1973007SG (5)

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MINING PLAN The portion of the sand deposit to be mined is all above the clay seam that separates the two water zones. Actually mining will stop a few feet above the clay seam as described later in this mining plan. Generally the sand on the northern end of the Little Johnson area and mostly outside the plume of affected water is more coarse than the sand on the southern portion of the mining area. Thus mining on the north end of the area will probably be more complete than the mining on the southern end of the area. But the mining plan map (Exhibit LJ C-4) shows the extraction to be fairly even in depth across the mining area. This equalized extraction plan is used because it is known that the sand deposit was variable where it has been mined ELSEWHERE in lase 4e THE SOUTH AREA. Insufficient data is available from the Little Johnson area to actually determine whether there are pockets of more coarse sand on the south end. Therefore, the mining plan assumes that all of the sand to the designed maximum depth will be removed, even though it is possible less will be removed on the south end than the north end of the mining area. The sand deposit itself is a blend of both alluvial and aeolian sands. Structure in the sand deposit clearly shows fairly continuous layers of sand of varying texture and thickness. This indicates a primary deposition by alluvial processes. Cross-bedding as seen in sand dunes is faint or absent. Undoubtedly though some of the sand was blown around on the dry land adjacent to the meandering water course,but aeolian sand constitutes a fairly minor amount of the sand deposit. This sand is probably of Pleistocene age and was probably deposited by Fountain Creek when it flowed across a broad outwash plain from the Pikes Peak area when the glaciers on the north and east sides of the mountain were melting. Undoubtedly, Monument Creek flowing southward from the Palmer Divide as well as other drainages such as Sand Creek contributed to the deposit. The layering in the sand deposit clearly indicates periods of vigorous erosion that deposited small amounts of gravel. These were mixed with periods of gentle flows that deposited mostly fine sand. The shape of the Pierre Shale bedrock in the valley indicates the presence of at least one major paleo-channel in this area. Section LJ-1 at the end of this exhibit shows a cross-section through the Little Johnson area along a basically west to east line. The zonation in the cross-section was derived from a compilation of data derived from a large number of exploratory drill holes, water treatment process drill holes, and monitoring well drill holes. However, because the various drill holes were not done at the same time or by the same people and were not logged by the same person, differences in the interpretation of the data obtained from the drill holes introduce some inconsistencies, especially with regard to the actual texture of the sand encountered. However, water levels and other major features such as the clay seam, when present, and bedrock are highly consistent between the drill holes. For those critical features of the structure that relate to the remediation program, the drill holes are considered to be highly reliable. Nearly all of the holes drilled were done for purposes of defining the remediation program rather than defining the sand deposit. Daniels Sand Pit Amendment (2008) Exhibit D Page 11 of 28