Land reclamation technology—expanding the geotechnical engineering envelope

Early approaches to land reclamation involved bulk removal of contaminated media using traditional geotechnical engineering technologies such as soil excavation and groundwater extraction. While these methods rely on readily available equipment and can be applied to a broad spectrum of contaminants, they are less than ideal. In the case of soil excavation, the approach is effective, but treatment is costly. Depending on the alternatives available, this approach may do little more than move the contamination from one site to another. With respect to groundwater extraction, the approach has proven to be very inefficient in many settings and requires extremely long time frames to complete. As a consequence, new technologies have emerged which attempt to exploit the chemical properties of contaminants to facilitate removal or destruction. The more developed of the new approaches are characterised in this paper, including how they work, how they are applied, potential limitations, and results from specific applications. While many of these new technologies have improved our ability to reclaim the land, significant limitations still leave undesirable results in terms of residual contamination and remedy cost. There is a need to continue improving and developing new technologies, especially those related to non-volatile contaminants and dense, free-phase liquids.