The application of natural attenuationc—cost-effective remediation that occurs without human interference—is based on extensive evaluation, modeling, and monitoring. Until now, cost-effective and portable analytical technologies to support its effectiveness did not exist. Under funding from the U.S. Air Force, CDM developed and field-tested a natural attenuation test kit that includes two analytical technologies—a self-contained dissolved hydrogen (DH) analyzer and a bioavailable ferric iron (Fe III) assay—to effectively and efficiently monitor two critical attenuation factors.
Field-Portable DH Analyzer Saves Time
Requiring minimal user training and powered by a 12-VDC automobile power outlet, the DH analyzer is the first field-portable alternative to the lab-based, time-consuming bubble-strip/reduction gas analyzer method. Using an innovative semiconductor chemical sensor to detect hydrogen and a series of built-in catalysts and adsorbents to remove interfering compounds, the analyzer automatically quantifies groundwater DH-an important indicator of the specific anaerobic microbial process responsible for contaminant plume biodegradation.
Fe III Bioassay Provides Subsurface Insight
The Fe III bioassay is the first standardized, systematic method to quantify bioavailable Fe III, iron essential to processes mediated by iron-reducing bacteria to degrade organic contaminants. Bioassay data will promote a keener understanding of the subsurface environment, helping optimize site cleanup through natural attenuation and other remediation technologies.
Testing Validates Cost-Saving Attenuation
Data from both analytical technologies can be used during site characterization and regulatory negotiations to validate natural attenuation's cleanup effectiveness, potentially saving millions of dollars over active remediation efforts and further promoting natural attenuation as a viable treatment option. The technologies also offer researchers additional tools to develop a keener understanding of the environment, biodegradation and biotransformation, and new site cleanup technologies.