2008-03-25_PERMIT FILE - M2008017 (2)

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Prelimina Sand and Gravel ' ry Mineral Evaluation Terracon Z9 Acre Parcel -East of Balsam Avenue Greeley, Weld County, Colorado Project No. 20015242 overlain by alluvial sands, gravels and clays of Pleistocene and/or Recent Age. The sand and gravel represent an ancient Terrace of the Poudre River. Soil and Bedrock Conditions The following describes the characteristics of the primary soil strata encountered at the site in order of increasing .depths, along with current groundwater conditions: • Qverburden Material -The overburden material consisted of slightly cohesive silty clayey sand (SC) with trace amounts of gravel and/or cobbles. This material was generally encountered at the surface and extended to depths of approximately 2-112 to 7-112-feet below the surtace. An approximate 3 to 7-foot Sandy Lean Clav lens was encountered at increased depths in Test Boring Nos. 1, 2, and 3 at approximately 47 to 56-feet below site grades. The silty Gayey sand layers are relatively fine in nature, medium dense in relative density and moist in-situ, while the clay layers are medium stiff to stiff in consistency and saturated. • Silty Sand with Gravel and Cobbles -Well Graded Sand with Gravel Wel! Graded Sand with Sitt. Poorly Graded Sand with Gravei Poorly Graded Gravel with Sand Poorly Graded ' Gravel with Silt and Sand,_ Well Graded Sand with Gravel and Well Graded Gravel with Sand -These strata were encountered in all borings at approximate depths of 2-1/2 to 7- 112 feet below the surface, and extended to the bedrock below in ail but Test Boring Nos. B-3, and B-4, where bedrock was not encountered to maximum depths of exploration, 90- feet. The sand and gravel stratum is poorly graded to well graded, loose to dense, contains moderate amounts of silt, and is moist to wet in-situ. it is estimated that the maximum size of gravel, and/or cobbles encountered with depth is typically less than 6- inches diameter. ' • Weathered Clavstone/Siltstone Bedrock -The bedrock stratum was encountered below the sand and gravel layer at approximate depths 68 to greater than 90-feet feet below existing site grades. • Groundwater -Groundwater was encountered in Test Boring Nos. 1, 2, and 3 at approximate depths of 4 to 4-112-feet below the surtace at the time of the initial exploration. Water measurements were not recorded for the Layne-Western test borings. However, it is anticipated that water levels would be relatively consistent at approximate depths of 4 to 6-feet below site grades. Water levels in this area are subject to change due to seasonal variations and fluctuations in irrigation practices. 4