The main advantage of ex situ treatment is that it generally requires shorter time periods, and there is more certainty about the uniformity of treatment because of the ability to monitor and continuously mix the ground water. Ex situ treatment, however, requires pumping of ground water, leading to increased costs and engineering for equipment, possible permitting, and material handling.

Physical/chemical treatment uses the physical properties of the contaminants or the contaminated medium to destroy (i.e., chemically convert), separate, or contain the contamination. UV oxidation is a destruction technology, and all other technologies included in this subsection are separation technologies.

Physical/chemical treatment is typically cost effective and can be completed in short time periods (in comparison with biological treatment). Equipment is readily available and is not engineering or energy-intensive. Treatment residuals from separation techniques will require treatment or disposal, which will add to the total project costs and may require permits.

Available ex situ physical/chemical treatment technologies include adsorption/absorption, advanced oxidation processes, air stripping, granulated activated carbon (GAC)/liquid phase carbon adsorption, ground water pumping, ion exchange, precipitation/coagulation/ flocculation, separation, sprinkler irrigation. These technologies are discussed in Section 4. Completed ex situ physical/chemical treatment projects for ground water, surface water, and leachate are shown in Table 3-15 and additional information on completed demonstration projects are shown on the FRTR Web Site.