Attachment B - Report of Geotechnical Exploration Samson Oceanfront Park Revised

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Report of Geotechnical Exploration November 7, 2014 Samson Oceanfront Park AREHNA Project B-14-124 4 | Page 4.0 SUBSURFACE CONDITIONS 4.1 USGS Topographic Data The topographic survey map published by the United States Geological Survey was reviewed for ground surface features at the proposed project location (Figure 3, Appendix A). Based on this review, the natural ground surface elevation at the project site is approximately +5 to +10 feet National Geodetic Vertical Datum of 1929 (NGVD). 4.2 USDA Natural Resources Conservation Service Data The United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) survey for Miami-Dade County indicates that the soils at the project site consist of the following soil units: Map Unit Symbol Map Unit Name 15 Urban land An excerpt from the published Soil Survey is provided below for reference: Characteristics of Urban land (mapping unit #15): This soil unit is in areas where more than 85 percent of the surface is covered by shopping centers, parking lots, streets, sidewalks, airports, large buildings, houses, and other structures. The natural soil cannot be observed. The soils in open areas, mostly lawns, vacant lots, playgrounds, and parks are mainly Udorthents. These soils generally have been altered by land grading and shaping or have been covered with about 18 inches of extremely stony, loamy fill material. The USDA Soil survey map for the project site is attached as Figure 4 in Appendix A. 4.3 Subsurface Conditions The Soil Test Boring Record in Appendix B should be consulted for a detailed description of the subsurface conditions encountered at the boring location. When reviewing the boring records and the subsurface profile, it should be understood that soil conditions may vary in areas away from the boring location. The boring generally encountered very loose to medium dense sands of various fines content (SP, SP-SM, and SM) to a depth of 29.5 feet. Some organic material was encountered at depths of 14.5 to 23 feet and 28 to 29.5 feet. Standard Penetration Test Resistances (N-values) ranged from 3 to 45 blows per foot. The limestone (WLS) formation was encountered beneath the sandy soils to the termination depth of 30 feet. The limestone was very soft with an N-value of 7 blows per foot. A page defining the terms and classification symbols used in the boring profiles is included in Appendix B of this report.