ABSTRACT
Two pilot-scale bioventing systems were evaluated during a 9-month operating period at an aviation gasoline spill site. The site subsurface was a uniform beach sand with the water table near 5-m depth. Prior to start-up of the venting systems, a grass cover was established and a nutrient solution was dispersed throughout the unsaturated subsurface. A nutrient solution was applied and turf was established prior to start-up of the venting systems. Subsurface soil gas concentrations of gasoline vapor increased to nearly 5000 mg/l total hydrocarbons when venting was started in October 1990. Within 3 weeks, concentrations decreased by a factor of 5, after which the decrease was much less. After 3 months of operation, the venting systems were shut down for the winter because the turf root zone was frozen.
