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Coulson Excavation Company Inc. -Stroh Gravel Pit Exhibit E -Reclamation Plan The borrow source for the compacted clay liner material is a weathered zone of Pierre shale that occurs within a strata of about 20-26 ft below ground surface at the Stroh pit location. The Pierre shale in this area is flat lying and laterally continuous texturally and mineralogical (Porter, 1976). The weathered zone is friable, silty clay. The clay minerals aze primarily illites and small amounts of smectites (Gill et al, 1996). Borrow Material Samplin,q/L,aboratory Analysis A 5-gallon sample of weathered Pierre shale was collected from a gravel operation approximately 1/3 mile to the east. The sample was collected from the upper 3 to 4 feet of the weathered horizon. Personal communication with local excavators and drillers indicate that the weathered Pierre shale in the area is very consistent laterally throughout the eastern Loveland area. This is most likely due to the flat lying nature of the shale unit in this region. The material appeared very consistent with respect to color and texture within the excavation. If the borrow material shows any variability with respect to color or texture or if the borrow material includes any material other than weathered Pierre shale, then the full suite of geotechnical tests will be performed. Field data recorded during sample collection included: Color -Dark gray Texture -Very fine grained clay and silt with larger clumps that aze friable with moderate pressure between fingertips Plasticity -Low Moisture -Moist The field sample was delivered to Aguirre Geotechnical Engineers of Englewood, Colorado. The following geotechnical tests were performed on the material: Gradation Analysis - 1 1/2" through #200 sieve Atterberg Limits -ASTM D-4318 Standard Proctor -ASTM D-698 Modified Proctor -ASTM D-1557 Data Analysis/Borrow Material Suitability The results of the geotechnical lab tests are: Gradation Analysis -passing 200 sieve =95.9% Atterberg Limits -Plastic Limit = 15, Plasticity Index = 24, Liquid Limit = 39 Standard Proctor -Optimum moisture content 16.2%, Laboratory Maximum Dry Density 108.9 pcf Modified Proctor -Optimum Moisture Content 13.9%, Laboratory Maximum Dry Density 117.7 pcf The goal of the design is to minimize hydraulic conductivity. Empirical relationships between plasticity index and clay content, plasticity index and hydraulic conductivity, percent fines and hydraulic conductivity, and clay content and hydraulic conductivity, have been shown by Benson et al. (1992). The ranges of hydraulic conductivities for the plasticity index of the sampled material aze shown in Table 1.