Assessing the Potential for Monitored Natural Attenuation at the Park-Euclid WQARF Site Using Compound Specific Isotope Analysis

Chlorinated solvents are the most common contaminants at the state and federal Superfund sites in Arizona and, given their myriad toxicological effects, pose a great risk to human health. The remediation of polluted soil and groundwater at the many chlorinated-solvent contaminated sites present in Arizona is critical for ensuring a safe and sustainable potable water supply.  Monitored natural attenuation (MNA) has recently gained great interest as a lower-cost approach for site remediation.  The primary driver of MNA feasibility is the rate at which contaminants are degraded. The goal of this project is to assess the feasibility of MNA using the Park-Euclid WQARF site as a model semi-arid environment chlorinated solvent site.  Reductive dechlorination of chlorinated ethenes results in a specific, replicable and measurable enrichment of ¹³C in the parent chlorinated solvent. This enrichment can be used to characterize biotransformation processes for a given compound.  Data obtained from these compound specific isotope (CSI) analyses will be used in concert with other biogeochemical data to help determine the suitability of MNA at the Park-Euclid WQARF site.