ISSN:
1745-6592
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Geosciences
Notes:
Strawberry Point, located on Hinchinbrook Island, Alaska, is the site of a Federal Aviation Administration air navigation facility that is contaminated with gasoline- and diesel-range hydrocarbons in soil and ground water. An air sparging system was installed to promote bioremediation in the zone of seasonal ground water fluctuation where the contaminant is concentrated. The sparge wells were placed in a homogeneous formation, consisting of fine-grain beach and eolian sands. The system was then evaluated to determine the ground water region of influence and optimum frequency of operation. Neutron probe borehole measurements of percentage; of fluid displacement during sparging at two wells revealed dynamic air distributions defined by an initial and relatively rapid expansion phase followed by a consolidation phase. Air distribution was stable within 12 hours after startup, reaching a peak air saturation of greater than 50 percent. The radius of peak expansion varied with time and depth, with measurable fluid displacement occurring beyond 12 feel from the sparge well near the water table. The percentage of air saturation stabilized within one hour following cutoff of the air flow, leaving pockets of entrapped air near the water table. When air injection was resumed, air saturation levels were found to be repeatable. The observations at this site indicated that the effective region of influence is relatively small and that frequent pulsing is needed to optimize oxygen distribution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1745-6592.1996.tb01175.x
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