J_2024 05 09_West Orange Stormwater Management Plan

August 8, 2022 File No. 26.0092704.00 PSE&G – West Orange, NJ Page 7 Proactive by Design Note that fluctuations in the level of the groundwater may occur due to variations in rainfall, temperature and other factors occurring since the time measurements were made. Findings and Recommendations General: Based on the results of our study, it is our opinion that: 1) The existing fill materials and buried topsoil, where present, cannot be relied upon, in their current condition, to provide direct support for the foundations for the proposed station improvements. Following the site preparation procedures described in subsequent sections of this report, the proposed lightly loaded improvements could be supported by conventional shallow foundations which derive their support from the undisturbed natural soils or controlled compacted fill installed after removal of the existing fill. Foundations may be designed for maximum net allowable bearing pressures of up to 4,000 pounds per square foot. The undisturbed natural soils and properly placed and compacted controlled fill would also provide adequate support for the control building floor slab and other slabs. Any lightning masts, towers or H-frames and any other structures subject to high lateral loads could be supported by either drilled shaft foundations or conventional spread foundations set at depths necessary to accommodate overturning forces. 2) Groundwater seepage was encountered at depths ranging from approximately 4 to 9 feet in the test pits at the time of this study and estimated to be near about 10 feet in several borings. As such, construction dewatering could be required, especially during the removal and replacement of existing fill materials. The site contractor should be responsible to provide whatever means and methods are necessary to dewater excavations and maintain control of surface runoff during construction. 3) The predominately near surface silty and clayey soils, which would represent the bulk of the excavated materials, would generally be poorly suited for reuse as fill or backfill as they would be highly susceptible to moisture-related stability and compaction problems. The following sections of this report present further discussion of each of these items. Site Preparation and Earthwork: Site preparation activities should initially include the removal of any existing equipment,

g sections of this report present further discussion of each of these items. Site Preparation and Earthwork: Site preparation activities should initially include the removal of any existing equipment, utilities, or improvements that are not incorporated in the Lifecycle project. Following An Equal Opportunity Employer M/F/V/H