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Geotechnical Report 2021 Street Improvements Hugo, Minnesota WSB Project No. 015887-000 Page 2 2. PROCEDURES 2.1 Boring Layout and Soil Sampling Procedures WSB completed 9 standard penetration soil borings along the proposed roadway reconstruction area. The borings were staked by a handheld GPS device for horizontal locations. The approximate boring locations are shown on the Soil Boring Exhibit in Appendix A which is an aerial photo. The ground surface elevations at the borings were estimated by using LIDAR data with 2-foot contours. These maps should be accurate to within +/- one foot (1’) provided ground surface modifications at this site have not been completed since LIDAR data was obtained. We completed the borings on July 29 and August 21, 2020 with a truck-mounted CME-55 drill rig operated by a two-person crew. The drill crew advanced the borings using continuous hollow stem augers. The drilling information is provided on the boring logs. Generally, the drill crew sampled the soil in advance of the aug er tip at two and one-half (2 ½) foot intervals to the termination depth of the boring. The soil samples were obtained using a split -barrel sampler which was driven into the ground during standard penetration tests in accordance with ASTM D 1586, Standard Method of Penetration Test and Split-Barrel Sampling of Soils. The materials encountered were described on field logs and representative samples were containerized and transported to our laboratory for further observation and testing. The samples were visually observed to estimate the distribution of grain sizes, plasticity, consistency, moisture condition, color, presence of lenses and seams, and apparent geologic origin. We classified the soils according to type using the Unified Soil Classification System (USCS). A chart describing the USCS is included in Appendix A. 2.2 Groundwater Measurements and Borehole Abandonment The drill crew observed the borings for free groundwater while drilling and after completion of the borings. These observations and measurements are noted on the boring logs. The crew then backfilled the borings to comply with Minnesota Department of Health regulations. 2.3 Boring Log Procedures and Qualifications The subsurface conditions encountered by the borings are illustrated on the Logs of Test Borings in Appendix A. Similar soils were grouped into the strata shown on the boring logs, and the appropriate estimated USCS classification symbols were also added. The depths and thickness of the subsurface strata indicated on the boring logs were estimated from the drill ing results. The transition between materials (horizontal and vertical) is approximate and is usually far more gradual than shown. Information on actual subsurface conditions exists only at the specific locations indicated and is relevant only to the time exploration was performed. Subsurface conditions and groundwater levels at other locations may differ from conditions found at the in dicated locations. The nature and extent of these conditions would not become evident until exposed by construction excavation. These stratification lines were used for our analytical purposes and, due to the aforementioned limitations, should not be used as a basis of design or construction cost estimates.