Abstract: An enhanced pressure gradient remediation system (10) for decontaminating a contaminated volume of soil incorporates at least one extraction well (40) operated independently or in conjunction with at least one injection well (12). The injection well (12) is employed to inject steam, or ambient or heated air, into the soil, and extraction probe (40) extracts fluids, contaminants (30,32,34) and possibly groundwater (58) from the soil. The invention further contemplates injection and extraction by means of recoverable extraction and injection probes (14) which obviate the need for permanent wells. The enhanced pressure gradient results from employing extraction in possible conjunction with injection at higher vacuum and pressure than previously known in the art.