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Phelan Development Holly Master Plan - Buildings H & 1 15188.000.006 Geotechnical Exploration - • EXPLTO GROUNDWATER ORATION GROUNDWATER ELEVATIONLOCATION (FEET) 4-CPT3 7 10 4-CPT4 7'/2 10'/2 4-CPT5 10'/4 9'/2 4-CPT6 10 10 4-CPT7 11'/2 8'/2 4-CPT8 13 7 4-CPT9 13 7 As part of previous studies performed by ENGEO for the larger Holly Sugar project, a piezometer (2-PZ4) was installed in the southeastern portion of the project site. Our records from fall 2018 show a high groundwater elevation of approximately 9'/2 feet, which corresponds to a depth of approximately 11'/2 feet bgs in the southeastern portion of the subject site. Fluctuations in the level of groundwater may occur due to variations in rainfall, irrigation practice, and other factors not evident at the time measurements were made. 2.6 LABORATORY TESTING We performed laboratory tests on selected soil samples to evaluate their engineering properties. For this project, we performed moisture content, dry density, unconfined compression, plasticity index, expansion index, hydrometer, resistance value, and soil corrosion potential testing. Moisture contents and dry densities are recorded on the boring logs in Appendix A; other laboratory data is included in Appendix B. 3.0 CONCLUSIONS From a geotechnical engineering viewpoint, in our opinion, the site is suitable for the proposed development, provided the geotechnical recommendations in this report are properly incorporated into the design plans and specifications. The primary geotechnical concerns that could affect development on the site are existing undocumented fill, shallow groundwater, expansive clay, and potentially liquefiable soil. We summarize our conclusions below. 3.1 EXISTING FILL Our test pits indicate that the portion of the site in the proposed vicinity of Building I is underlain by non-engineered, undocumented fill. Based on depth to fill encountered in our test pit explorations and their relative locations throughout the site, we estimate the volume of undocumented fill to be approximately 50,000 cubic yards. Figure 3 presents a subsurface cross section showing the geologic contacts of fill encountered in the vicinity of Building I. Non-engineered fills can undergo excessive settlement, especially under new fill or building loads. We recommend complete removal and recompaction of the existing fill. We present fill removal recommendations in Section 5.1. ENGEO December 13, 2021 Expect Exceltence