J_2024 05 09_West Orange Stormwater Management Plan

August 8, 2022 File No. 26.0092704.00 PSE&G – West Orange, NJ Page 8 Proactive by Design any demolition, the existing fill and any buried topsoil should be removed to the surface of the natural soils. The fill and buried topsoil in our recent explorations extended to depths ranging from 2.5 to 9 feet bgs. Based on our explorations, it is likely that excavations necessary to reach the plan foundation levels may not extend completely below the fill and buried topsoil into the natural soils. In areas where existing fill remains at the plan foundation bottom level, it should be removed to the surface of the natural bearing soils. Once it is confirmed that all existing fill materials have been removed, the foundations could be lowered to bear directly on the natural soils or the excavations backfilled with controlled compacted fill or crushed stone to the bottom of the foundation in accordance with the Suggested Foundation Overexcavation Detail presented on Plate 9. Excavations could be performed in a mass excavation, or depending on the proximity of other improvements, could be excavated in a series of isolated excavations. Following excavation of the fill materials and buried topsoil, the exposed natural subgrade soils should be observed by a qualified geotechnical engineer to confirm that all unsuitable soils have been removed. When excavations for new foundations are performed adjacent to existing foundations, the new foundations should be located so that a line drawn between the lower edges of adjoining footings shall not have a slope steeper than 30 degrees with the horizontal, unless the material supporting the higher footing is braced or retained or otherwise laterally supported. If some fill is left in-place in areas where new improvements are not proposed, in order to reduce the risk of excessive settlement in these areas, the existing fill should be proofrolled and recompacted to a relatively dense and stable condition and if observed, soft areas could be selectively excavated and replaced with An Equal Opportunity Employer M/F/V/H