In Situ Chemical Oxidation Remediation of a Chlorinated Solvent-Contaminated Site in Australia (Abstract)

摘要

Releases of chlorinated solvents from an industrial facility (the site) in Adelaide, Australia, have resulted in contamination of two shallow aquifers beneath and down- gradient of the site. The site is underlain by a sedimentary sequence of clay and sand deposits of Quaternary age extending to a depth of over 90 metres below ground level (mbgl). The shallow aquifers investigated beneath the site are present in two discrete sand and gravel horizons, the first occurring at 3-5 mbgl and the second at 8-10 mbgl. Dis- solved phase plumes of chlorinated volatile organic compounds (CVOCs), notably tri- chloroethene (TCE), cis-1,2-dichloroethene (cis-1,2-DCE) and vinyl chloride (VC), have been identified in both shallow aquifers beneath the site. These plumes correlated directly with areas at the site where degreasing activities were carried out in the past using a TCE- based solvent. Initial characterisation of the soil zone overlying the aquifers has shown that the soils contain only minor concentrations of CVOCs and that the bulk of the con- tamination appeared to be contained within the aquifers. To date, dense non-aqueous phase liquid (DNAPL) has not been identified at the site.