Geotech Report 04 19 2021

SOR CONSULTING ENGINEERS, INC. Garden Homes Report No. 21-C-12 Proposed Residential Development Page 12 West Orange, NJ The falling head permeability test results at the infiltration area (TP-14, TP-15) indicate that the loam material has a permeability rate ranging from 0.79 to 1.5 in/hr (K2 soils). Based on our evaluation of the subsurface conditions encountered in the test pits as well as the results of the laboratory test results, it is our opinion that the loam material encountered beneath the silt/clay loam is favorable for the construction of the detention basins or infiltration systems. The basins or infiltration systems should be designed based on the measured permeability rates for the subsoils encountered at these locations. Seismic Design Considerations: Structures must be designed in conformance with the applicable seismic design criteria of the New Jersey Edition of the 2015 International Building Code. In accordance with the Code, the subsurface information obtained from the borings and the known geologic conditions in this area, the site is considered to have a rock profile which corresponds to a site class “B”. Based on our analysis of the subsurface conditions, the field and laboratory test results and the known geology of this area, the on-site soils are not susceptible to liquefaction in a seismic event and the underlying bedrock is not considered susceptible to solutioning or the formation of sinkholes. RECOMMENDED SERVICES It is recommended that Sor Consulting Engineers be provided the opportunity for a general review of the final design and specifications to assure that the foundation and earthwork recommendations are properly interpreted and implemented in the construction documents. We also recommend that controlled compacted fill and backfill operations as well as foundation and floor slab subgrades be observed by a geotechnical engineer from our firm. This is to ensure compliance with the recommendations contained herein and to address any changes in the subsurface conditions that were not disclosed by the borings and test pits. Sor Consulting Engineers appreciates the opportunity to be of assistance with this project. Should there be any questions concerning the information provided herein,