Reformulated fuels such as diesel-ethanol blends (“diesohol”) and gasoline-ethanol blends (“gasohol”) are currently used or being considered in many countries to reduce atmospheric emissions and to reduce the dependence on foreign oil. Spillage and leakage may occur during production, transport, storage, handling, or application. There are concerns regarding the impact of ethanol and ethanol-blended fuels on the subsurface environment. Once in the subsurface, ethanol blended fuels may: (i) change water flow in the vadose zone, (ii) increase the aqueous solubility of polar organics, and (iii) interfere with the biodegradation of certain organic contaminants.

This study focuses on the potential impact of ethanol-blended fuels on the hydraulic properties of the vadose zone where fuel spills will occur and where contaminant remediation is most feasible. Water flow and contaminant transport in the vadose zone may be affected more strongly after contamination with ethanol-blended fuels than with conventional fuel due to changes in surface tension.

The purpose of this study was to conduct a series of experiments for different kinds of media  (e.g., sand, clay and porous rock) to elucidate changes in soil water retention and hydraulic conductivity caused by the presence of ethanol-blended fuels. The experimental tests allowed to detemine water retention curve and the saturated hydraulic conductivity in soil/rock samples saturated with aqueous solutions of ethanol and ethanol-blended fuel.