The Environmental Impact of Fossil Fuel Infrastructure and Cathodic Shielding on Groundwater Quality

2019 Faculty Research Award

Award Period: 2019-2021

Tullis Onstott, a Princeton professor of geosciences, will investigate if natural-gas pipelines designed to resist microbial corrosion increase the presence of toxic metals such as arsenic in groundwater. The researchers will work in Hunterdon County, New Jersey, examining up to 100 private and community wells in the vicinity of major gas pipelines that use Impressed Current Cathodic Protection (ICCP) systems, which use an electrical current designed to slow the corrosion of steel. This current also could stimulate the biogeochemical processes that release arsenic from the surrounding aquifer, leading to groundwater contamination. Samples will be gathered in the field during a two-year period with the help of the organization Raritan Headwaters and field tested for chemical signatures of arsenic migration, as well as for heat, carbon dioxide and methane leakages from the pipeline. Laboratory experiments will use soil from the well sites to reproduce the pipeline-trench environment and understand how ICCP-system current affects the microbial activity and geochemistry of arsenic and other elements. Data from the field and the laboratory will be used to calibrate a 2D reaction-transport model that simulates the impact of the pipeline on arsenic release into groundwater.

Keeley Walsh and Jake Martin of Princeton’s Class of 2019 collect soil samples above a natural gas pipeline in Hunterdon County, New Jersey, as part of preliminary work for the project.

Educational Impact

Undergraduates working as PEI summer interns will collect and analyze well water and soil samples; perform geochemical, isotopic and molecular analyses; and be trained in microbial biogeochemical cycling. Students will work directly with and communicate their results to property owners and community representatives. They will present their work to scientists from the NJ Department of Environmental Protection and non-profit and community water groups during a one-day workshop at Princeton focused on potentially regulating the installation of ICCP systems in environmentally vulnerable aquifers. Finally, students will have the opportunity to prepare and present their results at the American Geophysical Union’s Annual Meeting.

Future Directions

If the project indicates that ICCP systems do significantly impact biogeochemical processes, Onstott plans to submit a proposal to the National Science Foundation to support a more detailed study.

Participating Departments

Collaborating Institutions


Professor of Geosciences

Research Associates

  • Renxing Liang, Postdoctoral Research Associate, Geosciences

Additional Researchers

  • Kristi MacDonald, Director of Science, Raritan Headwaters

Graduate Students

  • Devan Nisson, GEO
  • Zachary Garvin, GEO

Undergraduate Students

  • Keeley Walsh ’19
  • Jake Martin ’19