Many good answers below, but ...
Published by John Salonich, Vice President / Managing Director
Many good answers below, but you first need to start cleanup with bulk removal using highly efficient oil/water separator, then treat the residual water for the balance of trace hydrocarbons, usually with activated carbon (which can be regenerated) and post filtration for secondary removal stages. Soils can be remediation using standard soil vapor extraction systems and then flushing the soil with hydrocarbon degrading bacteria using the vadose zone as an incubator for growing the bacteria. This is a simple explanation but there are other steps required as well, UV disinfection of treated water, et. al.