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Phase I Environmental Site Assessment Old Snelling Avenue & County Road E Improvements WSB Project No. 015447-000 Page 11 Based on the lack of contamination identified beyond the former fuel oil tank basin, Leak Site LS0012785 is not considered a REC. 5.3 Physical Setting Information ERIS provided a Physical Setting Report that details topographic, hydrologic, geologic, soil, wells and radon information for the Project Corridor. A copy of the ERIS Physical Setting Report is included as Appendix D. The following information was obtained through review of the report: · The Project Corridor elevation ranges from approximately 920 feet at the north end to 885 feet at the south end. The Project Corridor slopes gradually to the south towards Lakes Johanna and Josephine. · No wetland features were depicted at the Project Corridor. Multiple wetland features were illustrated adjacent to the Project corridor including freshwater ponds, freshwater emergent wetlands, and freshwater forested/shrub wetlands. Lakes Josephine and Johanna are located between approximately 615 feet and 1,230 feet west and 815 feet southeast of the Project Corridor, respectively. · Federal Emergency Management Agency (FEMA) flood zone data was available for the Project Corridor. The south end of the Project Corridor, where Old Snelling Avenue crosses over the creek connecting Lakes Johanna and Josephine, is classified as Flood Zone AE-11. Zone AE-11 is considered an area that has a 1% probability of flooding every year. The remainder of the Project Corridor is classified a Zone X-12, an area of minimal flood hazard. · The underlying bedrock geology at the Project Corridor consists of sandstone and limestone. The bedrock geology is reported as Middle Ordovician rocks, undivided- Decorah Shale; limestone of the Platteville Formation; shaly rocks of the Glenwood Formation; and St. Peter Sandstone in the Hollandale embayment of southeastern Minnesota. Based on information included in adjacent and surrounding well logs, the estimated depth to bedrock is greater than 120 feet below grade. · The surficial soil at the Project Corridor is primarily reported as urban land-Hayden- Kingsley complex. The Hayden-Kingsley complex consists of fine sandy loam, clay loam, and/or sandy loam. · No water wells are depicted at the Project Corridor. Multiple domestic water wells are depicted at adjacent sites. Based on information obtained from the well logs included in the Physical Setting Report, the estimated depth of static groundwater level at the Project Corridor ranges from 45 feet below grade at the south end to 95 feet below grade at the north end. Shallow groundwater was encountered at 14 feet below grade at two boring locations advanced during the 2019 Geotechnical Investigation (see Section 2.5). · Based on information obtained from the Physical Setting Report and the Minnesota Geologic Atlas for Ramsey County, groundwater is anticipated to flow southwest at the Project Corridor. It should be noted that groundwater flow can be subject to localized variation due to factors including geology, topography, soil type, drawdown from local wells, etc. · The Project Corridor is in Ramsey County which is classified as EPA Radon Zone 1. Counites in Zone 1 have predicted average indoor radon screening values greater than 4 picocuries per liter (pCi/L).