Technology Description

This project represents a collaborative effort among Shaw Environmental, the University of Illinois at Chicago, the U. S. Geological Survey, and Oak Ridge National Laboratory. Stable isotope ratio analysis of chlorine and oxygen in the perchlorate molecule will be employed as the primary forensic tool to identify perchlorate from different sources. This technique initially will be applied to a wide variety of solid perchlorate samples of differing origin to develop a broad database of isotopic signatures among natural and man-made materials. Once this database is established, groundwater samples will be collected from various locations, including known military sites and sites suspected to have natural contamination. Isotopic signatures of perchlorate in these waters then will be determined. These data will be evaluated with other geochemical variables, including iodine and tritium levels, to firmly establish perchlorate origin. Isotopic evaluation of perchlorate found in other environments, including soils, surface water, rainwater, and plant matter, also will be performed for source identification. In addition to forensics, recent data suggests that isotopic analysis is a sensitive technique to document and confirm perchlorate biodegradation during in situ remediation efforts. The utility of this technique for monitoring perchlorate in the field also will be validated in this project.