Short‐Term and Long‐Term Permeabilities of Contaminated Clays

The change in hydraulic conductivity of saturated clays due to short‐term and long‐term exposure of organic chemicals to clays is investigated to explain the change in hydraulic conductivity of contaminated soils. The long‐term exposure of soils to chemicals is simulated in a laboratory environment by premixing chemicals with soils. Under short‐term and simulated long‐term exposures of water soluble chemicals to soils, the hydraulic conductivities of laboratory consolidated clays are measured and reported. The permeability tests are performed using the both flexi‐wall and modified fixed‐wall permeameters with soil samples subjected to confining pressures. The fixed‐wall and flexi‐wall permeameters produced similar results. The short‐term permeability tests showed a change in hydraulic conductivity values but not the intrinsic permeabilities of soils. The simulated long‐term exposure of organic chemicals to soils showed a change in the soil structure and an increase in the intrinsic permeability of soils. The increasing trend in the intrinsic permeability of a given soil was weakly correlated to the decreasing dielectric constant of the pore fluid.