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5 3.4 OSHA Soil Classification The soils encountered in the borings consisted of poorly graded sand, poorly graded sand with silt and silty sand that correspond to the ASTM classifications of SP, SP-SM and SM, respectively. These soils will be Type C soils under Department of Labor Occupational Safety and Health Administration (OSHA) guidelines. An OSHA-approved qualified person should review the soil classification in the field. Excavations must comply with the requirements of OSHA 29 CFR, Part 1926, Subpart P, “Excavations and Trenches.” This document states excavation safety is the responsibility of the contractor. The project specifications should reference these OSHA requirements. 4.0 DISCUSSION AND RECOMMENDATIONS 4.1 Proposed Construction We understand that the project will include preparing lots and house pads for numerous single-family homes along with the associated streets, underground utilities and stormwater ponds. We were not provided specific architectural, structural or civil construction plans, but we assume the homes will be slab-on-grade structures but could include partial or full depth basements with one or two stories above grade. We anticipate below grade construction consisting of cast-in-place concrete foundation walls supported on concrete spread footings. The above grade construction is assumed to consist of wood framing, a pitched roof and asphalt shingles. Based on the assumed construction we estimate wall loadings will range from about 2 to 3 kips (2,000 to 3,000 pounds) per lineal foot and column loads, if any, will be on the order of 75 kips (75,000 pounds). We anticipate the buildings will be constructed at or near existing site grades so that cuts or fill for permanent grade changes will generally be on the order of 5 feet or less. We have attempted to describe our understanding of the project. If the proposed loads exceed these values or if the design or location of the proposed development changes, we should be informed. Additional analyses and revised recommendations may be necessary. 4.2 Discussion Several structures existed on the overall project site at the time of our exploration which we assume will be removed/demolished to make way for the new development. We recommend that all remnants of the structures including footings, foundation walls, floor slabs and underground utilities be removed from within the proposed building, roadway, utility and oversize areas and be properly disposed of off-site. The vegetation and topsoil are not suitable for foundation, roadway or utility support and will need to be removed from below the building pads, pavements, utilities and oversize areas and replaced with suitable competed engineered fill, as needed, to attain design grades.