10200 19TH AVE SE COSTCO FUEL STATION Geotech Report 2022-10-25

GEOTECHNICAL ENGINEERING STUDY Costco Wholesale c/o Barghausen Consulting Engineers E-8556 January 13, 1999 Page 3 Laboratory Testing Laboratory tests were conducted on several representative soil samples to verify or modify the field soil classification and to evaluate the general physical properties and engineering characteristics of the soil encountered. Moisture content tests were performed on all samples. The results of laboratory tests performed on specific samples are provided in Appendix B, or at the appropriate sample depth on the boring logs. It is important to note that these test results may not accurately represent the overall in-situ soil conditions. Our geotechnical recommendations are based on our interpretation of these test results and their use in guiding our engineering judgement. ECI cannot be responsible for the interpretation of these data by others. In accordance with our Standard Fee Schedule and General Conditions, the soil samples for this project will be discarded after a period of fifteen days following completion of this report unless we are otherwise directed in writing. DISCUSSION AND RECOMMENDATIONS General Based on the results of our study, it is our opinion the proposed development can be constructed generally as planned provided the recommendations contained in this report are incorporated into the final design. The critical geotechnical aspects of the planned development are associated with foundation support for the fueling canopy, construction of a stable excavation for the underground storage tanks, and controlling groundwater seepage, if encountered, in the planned excavations. In our opinion, the proposed fueling canopy can be supported on conventional spread and continuous footings bearing on the competent native soils underlying the fill deposit or new structural fill. The proposed controller enclosure can be similarly supported. The existing fill can be considered for use as structural fill, provided the fill can be compacted to the specifications of structural fill described in the "Site Preparation and General Earthwork" section of the report. As mentioned previously, the native soils were encountered below depths of approximately three feet at the boring locations. Specific recommendations for foundations are presented in the "Foundations" section of this report. Earth Consultants, Inc.