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Banks and Gesso, LLC Slope Stability Analysis This report describes the analysis to support mining within the 200 foot setback, per DMG Rule 6.4.19(b). The existing structures in the mine vicinity are power poles, buried cables, county roads, and natural gas pipelines. Background Data Borehole logs indicate that the site comprises an upper overburden layer of material, including topsoil, that extends to a depth of three feet, underlain by a layer of sand and gravel approximately 23 feet thick. Below the sand and gravel layer is bedrock. The soil survey for the area indicates that the upper layer of material within the proposed permit area consist of four soil types including Altvan loam, Aquolls and Aquents, Bankard sandy loam and Dacono clay loam. The engineering classification for these materials are low plasticity silts and clays (CL and ML) with 50% to 75% of the material passing the no. 200 sieve. Soils testing has not been completed for the Heit Property, thus no site-specific soils properties are known. Soil properties have been assumed based on research and knowledge of properties of similar materials. Conservative values have been assigned to the materials and are presented in the following table. Soil Type Dry Unit Weight (pct? Effective Cohesion, C (psf) Effective Friction Angle, F (degree) Overburden 115 200 20 Sand And Gravel 120 0 30 Bedrock NA NA NA Mining will begin at the southeast part of the site and proceed north and west. The sideslopes at the property boundaries and around structures will be mined to 0.5Horizontal:lVertical (0.5:1) and backfilled to the reclamation slope of 3:1/2:1. The slope will be at 3:1 from ground surface to ten feet below proposed water surface upon reclamation (the water surface is expected to be 3 feet below existing grade, therefore Heit Sand and Gravel Mine SW Meadow, LLC 02044 February 2003 30