scope:

1.1 Scope

The last decade has witnessed an evolution of remediation technologies starting with the early containment or mass reduction techniques to today's very aggressive site closure techniques, which address containment as well as residual petroleum hydrocarbon compounds. Initially, pump and treat systems were primarily used for the remediation of dissolved phase chemicals of concern. As time passed, the importance of addressing the trapped and adsorbed hydrocarbons present in the capillary fringe and saturated zone was realized due to the very slow asymptotic decline of the dissolved concentrations. Efforts were made to address trapped and adsorbed hydrocarbons, even though the dissolved plume may have stabilized.