A Permeable Membrane Sensor For The Detection Of Volatile Compounds In Soil

The large volume of site investigation workbeing performed since 1980 has spurred numerous attempts to improve<br>field methods of data collection. As part of this effort, GeoProbe Systems has developed two soil logging tools<br>which can be driven into soil to determine either lithology or contaminant concentration. These two tools are the<br>soil conductivity logging tool and the membrane interface probe. Both of these methods can be combined into the<br>same probe giving the site investigator a powerful means of collecting subsurface information. The soil conductivity<br>log of this probing tool is used to interpret lithology while the membrane interface probe is used to determine the<br>position and approximate concentration of volatile organic compounds (VOCs).<br>This paper will describe the principle of operation of the combined soil conductivity (SC) and membrane interface<br>probe (MIP). Data is presented in this paper from actual field use of<br>the MIP/SC logging system on fuel hydrocarbon and chlorinated<br>solvent contamination and comparisons are made to soil core analyses.