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Cripple Creek & Victor Gold Mine <br />Valley Leach Facility Expansions <br />Detailed Design for Permitting <br />NewFields Project No. 475.0106.064 <br />September 2025 <br /> <br /> <br /> <br />Page 7 <br />3.4.1. Natural Moisture <br />Samples were preserved at their natural moisture content by sealing the large, disturbed samples <br />in 5-gallon buckets. Moisture content testing was completed in accordance with ASTM D2216. <br />The volumetric moisture contents generally averaged 7 percent and ranged between 3 and 10 <br />percent. A relationship between depth and moisture content was not evident from the lab data. <br />The measured natural moisture content results are presented in Appendix B. <br />3.4.2. Index Properties and Material Characterization <br />The index properties (particle size analyses, ASTM D6913; and Atterberg limits, ASTM D4318) are <br />used to divide soils into groups with similar engineering properties. <br />In general, a particle size analysis divides individual soil samples into groups according to grain <br />size and determines the relative proportions by mass of each individual grouping. The results are <br />used to divide each specimen into percentages of gravel, sand, and fines. Fines are a grouped <br />classification for both silt- and clay-sized particles described as smaller than the No. 200 sieve <br />size (0.075 mm). <br />The Atterberg limits tests measure the moisture content of the upper and lower limits of the <br />range in which the soil is in the plastic state. The moisture content at the upper limit is known as <br />the liquid limit (LL) and the moisture content at the lower limit is designated as the plastic limit <br />(PL). The difference between the LL and the PL, termed the plasticity index (PI), is a measure of <br />soil plasticity. Generally, soils that exhibit a PI between 5 and 10 are low plasticity, between 10 <br />and 20 correlate to medium plasticity, and greater than 20 correlate to high plasticity. Soils that <br />do not exhibit cohesive behavior are termed non-plastic (NP) and non-viscous (NV). Atterberg <br />limit tests are performed on the portion of the material that passes the No. 40 (0.425 mm) sieve. <br />Foundation soils were generally classified as sands and gravels with varying amounts non-plastic <br />fines. The Particle Size Distributions are presented on Figure 3.1.