Non-invasive long-term on land geoelectrical monitoring oil contamination resulting from the Deepwater Horizon oil spill

Objectives:
We are conducting a geophysical monitoring experiment to investigate the sensitivity of electrical geophysical measurements to the biodegradation of oil from the Deepwater Horizon spill that has accumulated in beach sediments. This study builds on previous work of our team members that has demonstrated the sensitivity of electrical geophysical measurements to the biodegradation of hydrocarbons. For further information click here.

Study site:
We have established a long-term geophysical monitoring site on a remote beach area contaminated by oil from the Deepwater Horizon oil spill. Grand Terre I is an uninhabited island that was heavily impacted by the oil spill. It provides a “noise” free location for investigating the potential of non invasive electrical geophysical methods for long term monitoring of attenuation of the oil spill. The zone of oil contamination is located ~0.4-0.6 m below the surface and this contaminated layer is be bound by cleaner sand layers.

Map — *(a) Location of Grand Terre I in the Gulf of Mexico; (b) close up of Grand Terre I showing study site located at northernmost tip*

We have installed and maintained an autonomous, continuous resistivity monitoring system at this site. We also installed temperature and geochemical sensors to support the interpretation of the resistivity dataset. We have also performed an electromagnetic (EM) terrain conductivity survey using a multi-frequency instrument in order to obtain a rapid characterization of the spatial extend of the oil plume.

Field — *Site location on Grande Terre I showing (a) deployment of surface cable across a depression of known oil pooling, and (b) excavation at site showing the oil layer buried about 1 ft below surface*

Array w panels — Overview of the autonomous resistivity monitoring system showing solar panels for remote monitoring and surface electrode array; b) close up of the heart of the instrumentation for continuous, autonomous resistivity monitoring; c) Vertical probe array for corrections due to changes in environmental variables e.g. temperature

Project Team

PIs and co-PIs
Lee Slater (Rutgers-Newark) lslater@newark.rutgers.edu
Dimitrios Ntarlagiannis (Rutgers-Newark)
Estella Atekwana (Oklahoma State University)
Eliot Atekwana (Oklahoma State University)
Babu Fathepure (Oklahoma State Univesity)
Silvia Rossbach (Western Michigan University)

Other Senior Personnel
Dale Werkema (Environmental Protection Agency)

Graduate Students
Jeffrey Heenan (Rutgers-Newark)