Biological Effects Upon Capillary Barrier Surface Cap Performance

It is now generally recognized that some contaminated soils from waste disposal and spills can not be effectively remediated and will be left in the vadose zone. For contaminants such as radionuclides and metals, soil water advective transport is the major risk driver of these contaminants to the aquifer. To reduce the net infiltration of precipitation through these contaminated soils, capillary barrier surface caps have been proposed. Numerous studies have evaluated the physical design aspects of these caps. Despite the 100 to 1000 year design life of these caps, the long-term influences of chemical and biological effects on the performance of these caps have been ignored. This study will conceptually and numerically examine the effects of biological processes upon the performance of capillary barrier surface caps.