The fuels derived from petroleum have a high electric resistivity. For this reason,
when they are spilled into the ground they raise the resistivity of the environment.
After some time however, the action of bacterias over the organic compounds of
fuels produce their biodegradation with the formation of acid that dissolve ions of the
material of the ground, lowering the electric resistivity and transforming the
environment into a good conductor of electricity. In summary, spilling of fuels derived
from hydrocarbons produces plumes of contamination that have been associated, in
geophysical surveys, as much as resistivity highs, as very low values of resistivity. In
this work was intended to detect the signature in terms of resistivity of anomalies
associated to contamination by fuels derived from hydrocarbons at the São Paulo
Gas Station, an active gas station located in Abaetetuba-Pará and at the Braz de
Aguiar Gas Station, a deactivated station, located in Belém-Pará. The geophysical
measurement were carried through with the Ground Penetrating Radar Method
(GPR). The study was developed along profiles covering the external perimeter of
the gas stations, as well as their internal areas. The measurement were performed
using a monostatic 400 MHz antenna. The data were processed with the REFLEXW
software to improve the quality of the registers in order to make ease the
interpretation. A signature of low resistivity was found in both gas stations.
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