Coloration changes of geologic media after addition of gasoline,diesel fuel,and ethylbenzene

The coloration changes of three soils (Amarillo sandy loam, Anthony sandy loam, and Oakville sandy loam) and two clays (kaolinite and montmorillonite) were monitored following the addition of four solvents (distilled water, unleaded gasoline, diesel fuel, and ethylbenzene) over a time period of 1 year. Soil and clay coloration was measured using Munsell color charts. In general, the Amarillo soil experienced the most extensive changes to a darker, grayer color. Initial color changes occurred in as little as 1 week, with subsequent changes occurring throughout the next 41 weeks. This study indicates that solvents can alter geologic media color and that the inferred chemical reduction processes can be an ongoing process.