Abstract

Geophysical surveys were conducted in an area of petroleum-contaminated soil and groundwater in northeastern Arizona, near the Arizona–New Mexico border, along strategically located traverses by using a unique approach that integrates direct current electrical resistivity (ER), ground-penetrating radar (GPR), and very low-frequency electromagnetic induction (VLF) data. Using multiple geophysical methods provides cross checks that help provide reasonable constraints on possible geological models and interpretations. Previous borings at the site supplied information about total petroleum hydrocarbons to enhance interpretation of the geophysical data. The integrated ER, GPR, and VLF data correlate well, and vertical cross-sections generated from the geophysical data helped locate the hydrocarbon plume (both dissolved and free-product), which was delineated as an area of high interpreted resistivities.