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625 Cypress Avenue Geotechnical Investigation Project No. W1895-88-01 April 23, 2024 APPENDIX A FIELD INVESTIGATION The site was explored on March 4, 2023, by excavating two 8-inch-diameter borings using a truck-mounted hollow-stem auger drilling machine to depths of approximately 25 and 61 feet beneath the ground surface. In addition, a 4-inch-diameter boring was excavated to a depth of approximately 5 feet below ground surface using hand auger equipment. Percolation testing was performed in borings B2 and B3 to determine the infiltration rate of site soils. The site was further explored on March 13 and 14, 2024, by excavating two test pits to depths of approximately 15½ feet below the ground surface using hand tools and mechanical equipment. The test pits were excavated at the existing building foundations to verify footing depth and dimensions. Representative and relatively undisturbed samples were obtained by driving a 3-inch, O. D., California Modified Sampler into the “undisturbed” soil mass with blows from a 140-pound auto-hammer falling 30 inches as well as a slide hammer. The California Modified Sampler was equipped with 1-inch by 23/8-inch diameter brass sampler rings to facilitate soil removal and testing. Bulk samples were also obtained and Standard Penetration Tests were performed in borings B1 and B2. The soil conditions encountered in the borings and test pits were visually examined, classified and logged in general accordance with the Unified Soil Classification System (USCS). The logs of the borings and test pits are presented on Figures A1 through A6. The logs depict the soil and geologic conditions encountered and the depth at which samples were obtained. The logs also include our interpretation of the conditions between sampling intervals. Therefore, the logs contain both observed and interpreted data. We determined the lines designating the interface between soil materials on the logs using visual observations, penetration rates, excavation characteristics and other factors. The transition between materials may be abrupt or gradual. Where applicable, the logs were revised based on subsequent laboratory testing. The approximate locations of the borings and test pits are shown on Figure 2.