6624 BROADWAY 2018-01-02 MF Import

The planned project will include construction of low rise, multi -family housing. We I understand that current plans call for buildings constructed close to existing grade, and we therefore expect that excavation cuts and fills of less than about 5 feet will be required to reach subgrades for structures and paving. At this time, we understand that no specific building locations have been determined, and no grading plan has been formulated. We recommend that we be allowed to review project plans when they are available to provide situation -specific recommendations «here appropriate, and to prepare a final geo!echnical engineering report, if warranted. Additional subsurface explorations might be warranted depending on the design of the project. SUBSURFACE EXPLORATION We completed three shallow subsurface explorations with hand tools. The attached "Site and Exploration Plan," Figure 1, shows the approximate locations of the explorations. Logs of the subsurface explorations are also attached. Subsurface Conditions - Hand -Auger Borings The explorations were completed with a T-handled soil auger. The exploration borings were continuously observed and logged by a geologist from our firm. The exploration logs presented in the Appendix are based on the field logs, difficulty of excavation, and inspection of the samples secured. The explorations encountered surficial topsoil underlain by native soils that consisted of loose to medium dense sand. The native materials were silty in HA-2, and contained relatively little silt in HA-3. One hand auger boring, IIA-1, encountered loose fill soils consisting of silty sand with intermixed organic materials and asphalt rubble. We did not penetrate through the existing fill at the location of HA-1. Our explorations did not encounter free ground water. Subsurface Conclusions and interpretations I We interpreted the native subsurface materials observed in the explorations to represent ice contact sediments. Ice contact sediments are materials that were originally deposited on or within a glacial ice mass, and were subsequently redeposited when the ice melted. Ice contact sediments often resemble glacial outwash or lodgement till sediments, but are typically relatively loose. With proper preparation, the native sediments are suitable for support of conventional shallow foundations, paving, and structural fill. The existing fill observed in HA-1 was loose and contained organic material and asphalt rubble. The existing fill is not suitable for support of foundations and will require remedial preparation to support paving for driveways and parking areas. It should be noted that HA -I did not fully penetrate the existing fill, and therefore the fill is of unknown thickness in excess of 5 feet.