ABSTRACT
In Australia, estimates of the number of contaminated sites are as high as 80 000 (Natusch, 1997). Legislation and information on the site numbers and levels of contamination vary considerably between the Australian states. Methods for assessing these sites have been standardized across Australia with the implementation of the National Environmental Protection Measure for Assessment of Contaminated Sites. In the US and Europe, there is a growing emphasis on the use of site-specific risk assessment in order to determine the need for active remediation programmes. There is also an increasing reliance on natural attenuation (intrinsic remediation) if it can be shown that natural removal rates for contaminants will ensure that there is no long-term risk to human health or the environment. Where intervention is necessary, remediation can be conducted on-site, or at the facilities established for treatment of contaminated materials, usually contaminated soils. In the past, excavation and landfill disposal or on-site containment have dominated the treatment methods for contaminated soils (Natusch, 1997; Moss, 1997). There are many alternative treatment technologies now available for the remediation of contaminated soils, including bioremediation, soil washing, and thermal desorption (Martin and Bardos, 1996).
