Water Resources Research Act Program

Details for Project ID 2007AZ198B

Compound Specific Isotope Analysis of Natural Attenuation Activity in Chlorinated-Solvent Contaminated Aquifers

Institute: Arizona
Year Established: 2007 Start Date: 2007-03-01 End Date: 2008-02-29
Total Federal Funds: $10,000 Total Non-Federal Funds: $20,827

Principal Investigators: Mark Brusseau

Project Summary: The sustainability of potable water supplies is a critical issue in Arizona, given the recent and ongoing population increase, economic expansion, and arid climate. A major component of water-resources sustainability is the contamination of vital groundwater supplies by hazardous chemicals. In Arizona, chlorinated solvents, including tetrachloroethene (PCE), trichloroethene (TCE), dichloroethene (DCE), and vinyl chloride (VC), are the primary contaminant at 43 of 48 State and Federal Superfund sites. In aggregate, these sites comprise billions of liters of contaminated groundwater. Accordingly, these chlorinated-solvent contaminated sites pose a significant and long-term risk to the sustainability of potable groundwater in Arizona. Remediation of polluted soil and groundwater at chlorinated-solvent contaminated sites is therefore of immediate importance in protecting groundwater resources in the state of Arizona. Recently, monitored natural attenuation (MNA) has garnered increasing interest as a low cost, effective solution for remediation of contaminated groundwater. The successful application of MNA has the potential to save millions of dollars in remediation costs, as well as protecting the quality of critical groundwater resources. The goal of this project is to provide a simple and broadly applicable method to assess the feasibility of using MNA at chlorinated-solvent contaminated sites in Arizona. The availability of such a method would greatly enhance the ability to quickly and effectively evaluate sites, thereby providing valuable information for site owners and regulators. One potential low-cost, rapid method for directly identifying the presence of biological natural attenuation processes is Compound Specific Isotope (CSI) analysis. This method takes advantage of the natural fractionation of carbon isotopes during biological transformation. The specific objective of this project is the development of CSI analysis methods that will permit rapid and accurate screening of the suitability of Arizona sites for MNA.