Chemical and Physical Properties That Affect the Interaction Between Plants and Contaminated Groundwater

Abstract

This short summary of a true story received national media attention in January 2000 on the TV show “60min.” Although this specific incident occurred in California, the scenario could have occurred at any of the 400,000 leaky USTs across the United States in which gasoline that contained MTBE may have been stored. A leaky UST that contains gasoline enhanced with the fuel oxygenate MTBE can be accidentally released to the subsurface through corrosion in the joints of underground piping. After escape from the UST, gasoline as pure free product can migrate through the pore spaces of the unsaturated zone under the influence of gravity until it encounters the water-table surface. There, the lighter specific gravity of the gasoline will cause it to float on the water table as a separate phase. MTBE, and other gasoline compounds such as benzene, will then partition between the gasoline source itself and the air present in the unsaturated zone above the free product, the water present in the unsaturated zone as well as the water table, and the organic matter present in the soil.