Effect of the Addition of Clay and Wetting/Drying Cycles to the Contaminated Soils at the National Crude Oil Spill Fate and Natural Attenuation Research Site (NCOSFNARS)

Abstract

Although thirty-three years have passed since the 1979 pipeline break at the NCOSFNARS near Bemidji, Minnesota the soil within the zone sprayed by pipeline oil exhibits strong signs of oil contamination. The soils found within the spray zone are water repellent due to this contamination, and in result affects the growth of non-woody and woody vegetation. In the pursuit of providing alleviation techniques for oil-contaminated soils, a study has been initiated to evaluate the effectiveness of clay addition to alleviate soil hydrophobicity. This will be done by first conducting particle size distributions of the soil. Secondly, clay will be added at various rates and water repellency will be tested for using the molarity of ethanol (MED) test and water drop penetration time (WDPT) test. Lastly, wetting/drying cycles will be imposed on the sample and retested for water repellency.