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Old Snelling Avenue Roadway Improvements Arden Hills, Minnesota NTI Project No. 19.MSP09107.000 Page 2 of 3 2.2 Subsurface Conditions The soil profile generally consisted of bituminous pavement (generally ranging in thickness from 3.0 to 11.0 inches) overlaying apparent aggregate base (generally ranging in thickness from 8.0 to 24.0 inches). As an exception to this, Borings SB-14 and SB-15 encountered topsoil at the surface (approximately 5.0 inches in thickness). In Borings SB-1 through SB-7 and Boring SB-11, an additional bituminous pavement layer was encountered directly below the apparent aggregate base layer ranging in thickness from 6.0 to 11.0 inches. Apparent undocumented fill soils were encountered ranging in depths from approximately 1.5 to 11.5 feet below the existing grade. Generally, the undocumented fill soils consisted of clayey sand (SC), silty sand (SM), and sandy lean clay to lean clay with sand (CL). As an exception, apparent undocumented fill soils were not encountered at the Boring SB-10 location. The glacial deposits were generally encountered extending to the termination depths of the borings and consisted of clayey sand (SC), silty sand (SM), poorly graded sand (SP), and sandy lean clay (CL). A paludal deposit generally consisted of peat (Pt) soil was encountered at the Boring SB-8 location between depths of approximately 7.0 and 9.0 feet below existing grade. Apparent hydrocarbon odors (detected by human perception only) were observed throughout the project area. Please refer to the boring logs within the appendices for a detailed description and depths of stratum at each boring. Additional comment on the evaluation of recovered soil samples is presented within the report attachments. 2.3 Groundwater Conditions The drill crew observed the borings for groundwater (if any) during and at the completion of drilling activities. Measurable groundwater was observed in two (2) of the fifteen (15) SPT borings (SB-1 and SB-12) at a depth of approximately 14.0 feet below existing grade (approximate elevations of 877.76 and 900.23 feet). Possible perched groundwater conditions were observed at Boring SB-6 at a depth of approximately 11.5 feet (approximately elevation 901.01 feet) The site soils were conducive to movement of groundwater both laterally and vertically over time. The moisture content of such soils can vary annually and per recent precipitation. Such soils and other regional dependent conditions may produce groundwater entry of project excavations.