Geotech Report 04 19 2021

SOR CONSULTING ENGINEERS, INC. Garden Homes Report No. 21-C-12 Proposed Residential Development Page 6 West Orange, NJ Groundwater was not encountered in the majority of the explorations performed for this study. However, where encountered, slight water seepage was observed at depths ranging from 2 to 9 feet below surface. Due to the substantial topographic relief, it should be anticipated that groundwater levels at the site will vary significantly and may experience fluctuation due to seasonal variations in precipitation, temperature and/or surface runoff. In addition, groundwater seepage may be localized occurring along the bedrock surface. CONCLUSIONS AND RECOMMENDATIONS General: Based on our evaluation of the encountered subsurface conditions, the natural residual soils, new controlled compacted fill and basalt bedrock will provide suitable support for the foundations and slabs of the proposed structures. Following the site preparation procedures presented in this report, the columns and walls of the proposed structure may be supported on conventional spread foundations. Slabs may be constructed on grade. Discussions of these and other geotechnical items considered relevant to the proposed construction are presented in the following sections of this report. Site Preparation and Earthwork: All trees, topsoil and vegetation should be completely removed from within and at least 5 feet beyond the proposed construction limits. Following the removing of all surface vegetation and topsoil, excavation should continue as required to reach the proposed construction subgrade levels. Any unsuitable fill encountered should also be removed. Based on the topography of the site, we anticipate that excavation into bedrock will likely be required. Basalt is very dense, fine grained igneous rock. Typically, the upper 1 foot of the rock may be somewhat weathered and fractured, and capable of being excavated using heavy construction equipment. Below this, however, the rock is less weathered and less fractured. Consequently, excavations extending more than 1 foot into rock as well as excavations in confined areas such as foundation and utility excavations, will likely require drilling and splitting, blasting, pneumatic hammering or other specialized techniques for rock removal. w