Groundwater and Dewatering. A subsurface investigation conducted in August and September of 2018 and consisting of soil borings and groundwater well installations throughout the Project Route has determined that there are several locations where groundwater can be expected to be encountered during excavation activities associated with the Project. Based on these findings and a review of the 60 Percent Plan and Profile (“P&P”) Drawings dewatering will likely be required at several locations on the upland construction of the Project, most notably during excavation and installation of splice vaults (as further detailed in SOP EG-706 Excavation Dewatering). The results of the subsurface investigation do not indicate that groundwater along the Project route is likely to be contaminated. The Certificate Holder has prepared a SWPPP and will obtain the requisite Municipal Separate Storm Sewer Systems (“MS4s”) acceptance of the SWPPP from the MS4s before construction begins. A list of MS4 administrators and their contact information are included with the SWPPP. In the event that dewatering is required, the Environmental Monitor will be notified prior to any dewatering activities. The Environmental Monitor will be responsible for assessing the water for obvious signs of contamination, such as separate-phase product, odors or sheens, before dewatering can begin. If the assessment shows noevidence of contamination, best management practices still need to be followed in order to avoid erosion and sediment migration concerns. Dewatering will follow the PSEG Long Island SOP EG-706 and will likely be performed by use of portable pumps drawing through a suction line and discharging through a flexible hose. Water will be pumped from the excavation, settled in a container, tank, or temporary basin and filtered through sediment filter bags before discharge into storm drains or sewer inlets. Per EG-706, filter fabric must be used over storm drains and sewer inlets prior to discharging any water to them. If no storm drains or other drainage systems are available, water may be discharged to the ground, provided the discharge location is down gradient from the excavation area and the affected property can accommodate the infiltration of the discharged water. In no such situations shall the water be discharged in private properties, wetlands, wetland adjacent areas or allowed to flow onto private properties, wetlands and wetland adjacent areas. In the event that contamination is suspected based on observed s...
