2005-03-04_REVISION - M1973007SG

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MINING PLAN Exhibit D LITTLE JOHNSON AMENDMENT Mining Plan INTRODUCTION AND OVERVIEW: The following mining plan primarily addresses the Little Johnson amendment area and how it integrates with the adjacent Phase 4e. In essence, this amended mining plan extends the Phase 4e mining eastward into the former Little Johnson reservoir azea. This reservoir has not had water stored in it for many years and is basically a dry basin underlain by sand. This basin is also underlain by tetrachloroethene (PCE) affected groundwater that is being treated and reinjected into the aquifer after treatment. This remediation program is required by the Colorado Department of Public Health and Environment. However, within rather tightly specified limits, the sand deposit in the Little Johnson area can be partially extracted without adversely affecting the remediation program. The final effect of this additional mining will produce a far more favorable reclamation product on the east end of Phase 4e. The addition of this sand area will help to maximize the extraction of a valuable resource needed for the continued growth of Colorado Springs. Other than this deposit, there are few high quality and high volume sand deposits within a reasonable distance of Colorado Springs. It is therefore important that this deposit be extracted to the full extent possible. NATURE OF DEPOSIT AND UNDERLYING MATERIALS: The sand contained in the Little Johnson azea is an extension of the sand deposit mined immediately west of this area in Phase 4e of the current permit. However, the deposit differs in that it becomes increasingly shallow to the east. The Pierre Shale bedrock under the deposit rises rapidly in an easterly direction across the old reservoir area and reaches a near surface exposure on the east end of the site or just beyond. The shale does not appear to be exposed in that area but is covered by a thin layer of sand and clay loam soil. Paralleling the bedrock is a discontinuous clay seam from a few inches to a few feet thick. This seam delineates the boundary between the upper water zone and the lower water zone that is being treated. Near the current permit boundary the sand just above the clay seam, which is about 50 to 60 feet below the surface at that point, is moist but rarely wet. Moisture content above the clay seam increases in an easterly direction and apparently rises somewhat faster toward the surface than the clay seam itself does. The Bradley Road groundwater extraction wells (Exhibit C-3), located just west of the affected land boundary but several hundred feet west of the mining limit, captures groundwater in the upper and lower water zones. The Little Johnson Reservoir (LJR) ground water extraction wells Daniels Sand Pit #2 -Little Johnson Amendment - M-ts73-oo~ Exhibit D Page 1