VAPOR PRESSURE CHARACTERIZATION TO PREDICT CONTAMINANT RELEASE RATES FROM MGP SITE SOILS

摘要

The risk-based management of contaminated sites often requires the rapid screening and identification of source areas that are the cause of contaminant releases to groundwater and to other reception of concern. Over reliance on total concentrations often results in costly site characterization, delays in remedial actions and in overestimation of the volumes of soils targeted for removal on treatment. The overall objective of the work described in this paper is to determine the potential of using vapor pressure measurements as a rapid indicator of the mass release potential of suspected source area soils. The current work has primarily focused on determining the vapor pressure of PAH’s and BTEX in contaminated soils to establish the mechanisms related to contaminant-soil binding. This work ascertained that for a wide spectrum of nonionized, aromatic contaminants in MGP soils, total vapor pressure and benzene partial pressure could be measured with good repeatability. These vapor pressure measurements on 16 soil samples taken from two MGP sites were found to correlate well to measurements of equilibrium partitioning and resin mediated soil contaminant desorption ratios with R2 values of over 0.9. Risk screening protocols based on vapor pressure show the potential of improving the reliability and the time required to classify soils that are suspected sources of contaminants.