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Field Investigation Report Old Snelling Avenue and County Road E Improvements WSB Project No. R-015447-000 Page 5 2. Investigation A total of 16 environmental borings (EB-1 through EB-14; SV-2 and SV-9) were advanced at the Project Corridor on April 16 and 17, 2020 to investigate potential impacts to soil, groundwater, and soil vapor. The environmental borings were completed by Bergerson Caswell Inc. of Maple Plain, Minnesota using a truck-mounted push probe drill rig. The environmental boring locations are depicted on Figure 2. 2.1 Soil Sampling Continuous sampling, using a four-foot long rod with a new acetate liner for each sample, was conducted at each boring to a terminus depth of 16 feet below grade. Soil profiles were assessed at two-foot intervals and labeled accordingly. Each sample was visually examined for evidence of contamination, field classified, and screened for organic vapors using a PID equipped with a 10.6 eV lamp. Soil boring logs are included as Appendix B. A total of 28 soil samples were collected during this investigation and submitted to Eurofins TestAmerica Laboratory of Cedar Falls, Iowa (Eurofins) for analysis of DRO, GRO, BTEX, VOCs, lead, RCRA Metals, PAHs, and/or PCBs. Two soil samples were submitted from each boring. Soil samples were submitted from intervals with evidence of contamination (e.g. elevated PID readings, petroleum-like odors, staining, etc.). If no evidence of contamination was observed, samples were submitted from intervals of 4-6 feet below grade and 8-10 feet below grade. The soil samples collected from borings EB-1, EB-2, and EB-8 were submitted for laboratory analysis of full VOCs (rather than only BTEX) due to evidence of contamination observed in the field. Soil samples EB-3 (8-10), EB-8 (2-4), EB-8 (8-10), and EB-13 (4-6) were submitted for laboratory analysis of full RCRA Metals (rather than only lead) and PCBs for waste characterization and landfill acceptance purposes. Laboratory reports are included as Appendix C. Following completion of sampling and screening activities, the borings were sealed with bentonite grout in accordance with MDH requirements. 2.2 Groundwater Sampling Three (3) groundwater samples were collected from borings EB-1, EB-8, and EB-12 and submitted to Eurofins for analysis of DRO, GRO, VOCs, and lead. Shallow groundwater was encountered in these three borings at depths ranging from 5.10 to 12.05 feet below grade. Groundwater was not encountered in the remaining 11 borings. Groundwater samples were collected by installing a temporary PVC monitoring well screen and using a check valve and polyethylene tubing to draw the sample. Water level measurements and screen depths are included in the soil boring logs in Appendix B. Groundwater samples were identified using the boring number. 2.3 Soil Vapor Sampling Two (2) soil vapor samples, SV-2 and SV-9, were advanced to 4 feet below grade and submitted to Eurofins for analysis of VOCs. The soil vapor samples were paired with their respective boring numbers (e.g. soil vapor sample SV-2 was collected at boring EB-2). The soil vapor samples were collected using 1-liter stainless steel canisters equipped with a regulator calibrated to collect a 5-minute sample draw.