The contamination of soil by light hydrocarbons is one of the most frequently encountered environmental problems. Leakage from underground storage tanks at refueling stations is the most common source, but others are refineries or production facilities. Research at the University of Calgary has been examining the application of proven petroleum reservoir engineering methods to address this issue. By use of horizontal boreholes, and cyclic water and gas injection, the contaminant can be recovered in situ. Laboratory work has been ongoing to determine basic data on the contamination and remediation aspects of the process. In this paper, we report work that has been done to characterize the saturations during the contamination and remediation processes. Sand that typifies the grain shape and distribution of native soil was used. This sand was strongly water wet. To examine the impact of the humic acid from topsoil loam, humic acid was extracted and plated onto the sand. Characterization of the sand has been performed to demonstrate that the humic acid has bound to the surface of the sand grain, and has altered the surface wettability. Results of coreflooding also demonstrated that the performance of the organic coated sand, and the untreated sand, will lead to different contamination and remediation results. It appears that the treated sand exhibits hysteresis, for if it was originally in contact with water, it behaves as if water we. If, instead, it was originally in contact with kerosene, it behaves as if oil wet.