An approach to optimize the location of LNAPL recovery wells using the concept of a LNAPL specific yield.

Leakage of hydrocarbon fuel (light nonaqueous-phase liquid, LNAPL) from petroleum processing facilities and storage tanks may result in significant subsurface contamination. Remediating the contaminated areas represent considerable challenges, especially when remediation resources are limited and site data are incomplete. A reasonable management strategy under this scenario may be to identify sites where LNAPL recovery operations should be located that would provide the largest LNAPL recovery initially while minimizing the LNAPL remaining in the subsurface (entrapped and residual LNAPL), which may serve as future sources for groundwater contamination. To accomplish this objective, we use estimates of subsurface recoverable and total LNAPL specific volumes and LNAPL transmissivities to generate GIS maps that can be combined to highlight locations where to develop LNAPL recovery operations. When the approach is applied to a LNAPL-contaminated area in Iran, we were able to narrow the locations for potential LNAPL recovery operations. Specifically, we combine maps of the LNAPL specific yield, an introduced term, and the LNAPL transmissivity where the LNAPL specific yield is the ratio of the recoverable to total LNAPL specific volumes. The LNAPL specific yield is a relative measure of the amount of LNAPL that potentially can be recovered while minimizing residual LNAPL in soils. The approach can be applied to sites where the recoverable and total LNAPL specific volumes and LNAPL transmissivities can be estimated using data from boreholes in the contaminated area.