Some soils, such as clay or rock, are difficult to remediate by in-situ technologies because their structure inhibits or prevents the efficient distribution of air, nutrients, additives, microbes, and other materials that must travel through the soil and rock to reach and act upon the contaminants. In pneumatic fracturing, air is injected into the ground more rapidly than the ground can accept it. Because the air has nowhere to go, it builds up until the earth fractures, creating a network of cracks. The fractures allow vapors or liquids to flow more readily through the formation, so contaminants are more accessible.
Generally the result is an increase in contaminant removal of 10 times or more, depending on the site's geology and its initial level of contamination. Cost savings employing this technology range from 20 percent ($0.8 million per acre) for a moderate-permeability site to 80 percent ($16 million per acre) for a low-permeability site.
For further information, contact:
John R. Schuring
Professor
Department of Civil and Environmental Engineering
New Jersey Institute of Technology
Newark, New Jersey 07102-1982 USA
Phone: (973) 596-5849
E-mail: schuring@adm.njit.edu