Report/subsurface exploration/geotechnical review

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AET#22-00173- Page 8 of l0 Potential Difficulties The soils that were encountered in our boring are susceptible to disturbance by construction traffic, especially when saturated or exposed to free groundwater. Disturbed soils should be carefully excavated and replaced with new compacted, engineered fill. Observation and Testi�� The recommendations in this report are based on the subsurface conditions found at our test boring location. Since soil conditions can vary, we recommend on-site observations by a Geotechnical Engineer or a Material Technician during construction to evaluate the soils. Soil density testing should be performed on all fill placed at the site to document that our recommendations, and the specifications for compaction and moisture have been satisfied. Where fill material type is important, laboratory sieve analyses should be performed to document that the fill meets the recommendation gradation criteria. SUBSURFACE EXPLORATION Our subsurface exploration program included drilling one standard penetration test (SPT) boring at this site on February 1, 2008. Oak Hill, Inc. staked the boring location in the field and our drill crew shot the ground surface elevation at the boring referenced to the top of the existing manhole located east and south of the lot on Crystal Bay Road. This benchmark had an elevation of 933.4 feet National Geodetic Vertical Datum (NGVD). Before we drilled, we contacted Gopher State One Call to locate public underground utilities on this site. We drilled the borings using 3 1/4 inch inside diameter hollow stem augers and mud rotary techniques. We backfilled the borehole with neat cement to comply with current Minnesota Department of Health regulations. [Refer to the sheet in the Appendix entitled "Exploration/Classification Methods" for detail regarding drilling and sampling of standard penetration borings, and methods used so classify soils and measure water levels.]