Water Resources Research Act Program

Details for Project ID 2017NJ389B

Using geophysical technologies to delineate and monitor saltwater intrusion within New Jersey coastal aquifers

Institute: New Jersey
Year Established: 2017 Start Date: 2017-03-01 End Date: 2018-02-28
Total Federal Funds: $20,000 Total Non-Federal Funds: $40,000

Principal Investigators: Judy Robinson, Lee Slater

Project Summary: Saltwater intrusion of coastal aquifers is one of New Jersey’s (NJ) most critical water resources issues. Exacerbating this situation are the increased demands from an increasing population and rising sea levels as a result of climate change. NJ State agencies are committed to serving the water needs of residents by conducting water quality monitoring from wells throughout the state. While this provides accurate information at discrete intervals for a particular location, these point-scale measurements must be spatially interpolated and up-scaled to provide a time snapshot of regional information. This project proposes to use the information from the existing network of monitoring wells with the geophysical methods, electrical resistivity tomography (ERT) and self-potential (SP) to delineate and remotely monitor salt water intrusion processes of a NJ coastal aquifer at a critical location. These geophysical methods are sensitive to conductivity contrasts and pressure and concentration gradients associated with salt-water intrusion and provide information at a scale consistent with subsurface processes resource professionals need to make informed decisions regarding water management. Numerous studies have shown that ERT is a viable way to monitor conductivity variations associated with salt-water intrusion. Newer research suggests an increase in SP can detect saline breakthrough prior to the actual intrusion. This project aims to provide proof-of-concept that autonomous ERT monitoring can be used to collect ERT datasets while subsequent processing can provide near real-time information. In addition, the capability of SP measurements to detect saline breakthrough both within boreholes and on the surface will be tested.