NJ Back Bays Coastal Storm Risk Management Feasibility Study & Subsurface Exploration

The New Jersey Back Bay (NJBB) Coastal Storm Risk Management (CSRM) feasibility study is focused on the approximately 100 miles of interconnected tidal water bodies and coastal lakes located landward of the New Jersey Ocean coastline from the Manasquan Inlet to the Cape May Inlet. These areas were subject to recent flooding, storm surge, and damages as a result of Hurricane Sandy and other storm events. As part of this study, the United States Army Corps of Engineers (USACE) Philadelphia District developed a preliminary alignment for a storm surge barrier located in Great Egg Harbor Inlet in Atlantic and Cape May Counties. This preliminary barrier would serve as the representative design for all planned storm surge barriers as part of the project.

Through an existing contract with USACE Philadelphia District, Princeton Hydro was tasked with performing a water-based subsurface exploration along the preliminary barrier alignment. This exploration consisted of nine (9) Cone Penetration Tests (CPTs) with continuous pore pressure measurements to a maximum depth of 150 ft below the mudline or until refusal was encountered. To perform the testing, Princeton Hydro required subcontracted services provided by Northstar Marine Services, Inc., ConeTec, and Boring Brothers, Inc.

CPT soundings were performed from Northstar Marine Services’ 70 ft Lift Boat, the Vision. A rubber track mounted, low- clearance drill rig was provided by Boring Brothers, Inc. to socket casings into the mudline by way of the moon pool of the barge. Once casings were set, ConeTec utilized their Direct Push Overwater Ramset to continuously advance the CPT soundings to the termination depth. During the entire operation, Princeton Hydro provided continuous oversight as well as regular Health and Safety Inspections. The information collected during the investigation was provided to USACE for use in the design of the storm surge barrier.