ABSTRACT
Identification, assessment, and remediation of petroleum contaminated sites is a major task facing civilized society. Thousands of these sites exist in the country. Traditional assessment technology for the definition of the spatial extent of contamination involves the collection and laboratory analysis of samples of the various environmental media. The economic pressures engendered by the extremely large number of petroleum sites to be dealt with has spawned the development of several screening methodologies, which can provide a cost-effective alternative to the traditional sampling and laboratory analysis. The passive technique has several apparent disadvantages in that it requires two and possibly more field efforts, and the chemical data are not acquired in real time. Additionally the passive technique relies on the natural flux of vapor phase components to move to the collector, and the rate of this natural movement is often very slow and also variable, depending on soil permeability, moisture content, temperature, and atmospheric pressure.
