Evaluation of Effectiveness of Soil Gas and Groundwater Monitoring for Underground Storage Tanks

摘要

Potential of leakage of a underground storage tank (UST) of gasoline station increases with its servicernlife. In order to avoid serious pollution caused by the dissolution of toxic constituents in LNAPLs (Lightrnnon-aqueous phase liquids), monitoring measures are employed to provide early warning. Among thernmonitoring methods, soil gas and groundwater monitoring detect the leaked product directly. Thernpathway of leaked gasoline flows and diffuses and thus, in turn the effectiveness of soil gas andrngroundwater monitoring, may be affected by the existence of USTs of gasoline station. In this study,rnnumerical simulation with the software TMVOC was performed in order to assess the effectiveness ofrnsoil gas and groundwater monitoring. The results show that both soil gas and groundwater monitoringrnare more effective if the site has a shallow groundwater table and the soil has higher hydraulicrnconductivity and lower porosity. The effectiveness of soil gas monitoring is better than groundwaterrnmonitoring in general, when soil gas and groundwater monitor well are far away leakage then therngroundwater monitoring is better than soil gas.