Current pump-and-treat P&T. techniques are ineffective in dissolving dense non-
aqueous phase liquids DNAPLs. in the subsurface. The main reason of the failure to
remove liquid DNAPL from the subsurface using P&T is the relatively low aqueous
solubility of most DNAPLs. The surfactant flushing SF. technology, also referred to as
surfactant enhanced aquifer remediation SEAR., is a relatively new technology for
removing organic liquids from the subsurface environment. A detailed overview of the
fundamental processes associated with SF as well as some practical applications can be
found in a recent contribution by Pennell and Abriola 1997.. The technology has been
developed based on techniques used in enhanced oil recovery where surfactants are
injected in reservoirs to mobilize entrapped crude oil Nelson and Pope, 1978.. Applied
as an environmental remediation technology, surfactants have been used to solubilize
and mobilize entrapped organic liquids.