Over the past 20 years, ESTCP has demonstrated many technologies designed to protect and remediate groundwater impacted with chemicals of concern. While substantial progress has been made to manage Department of Defense (DoD) sites impacted by chemicals such as per-and polyfluoroalkyl substances (PFAS), challenges remain. PFAS often occur with co-occurring chemicals of concern, which complicates treatment and management options.

In 2021, ESTCP funded new projects that will demonstrate cost-effective management tools and technologies to address PFAS-impacted sites. 

• Dr. Bo Guo at the University of Arizona will develop and demonstrate an advanced comprehensive decision support platform capable of predicting PFAS leaching in source zones. This platform will aid the development of remedial action objectives and evaluation of remediation approaches at DoD sites (Project Overview).
• Dr. Craig Divine at Arcadis demonstrated the Horizontal Reactive Media Treatment Well (HRX Well®) technology under a previous ESTCP project, confirming its hydraulic, treatment, and long-term mass discharge control features. In this new project, Dr. Divine will demonstrate the in situ reactor technology (InSRT), designed by Clarkson University to treat PFAS within an HRX Well for destructive PFAS treatment in an existing HRX Well (Project Overview).
• At CDM Smith, Dr. Dung Nguyen and his team will combine the use of conventional sparge trench technology and recently developed foam fractionation technology to remove PFAS from groundwater. The treatment approach has the potential to treat PFAS-impacted groundwater in situ, which has not yet been demonstrated at field-scale settings to the extent of ex situ treatments. The project team aims to reduce energy consumption and waste generation with this approach (Project Overview).
• Dr. Erika Houtz at Arcadis US, Inc. and her team will field-validate the use of a portable electrochemical sensor technology for rapid PFAS assessment. The sensor is an adaptable technology developed collaboratively by the Pacific Northwest National Laboratory and the New Jersey Institute of Technology that will be integrated into a broad range of applications, such as initial characterization and remedy evaluation in this project (Project Overview).
• At Texas Tech University, Dr. William Jackson will demonstrate high-resolution delineation of PFAS in groundwater aquifers using a high-resolution passive profiler (HRPP). The HRPP was developed and field validated under a previous SERDP project led by Dr. Jackson, so it is expected to provide valuable insights into PFAS fate and transport (Project Overview).
• Dr. Frank Barranco at EA Engineering, Science, and Technology, Inc. and his team will treat PFAS-impacted soil using ex situ thermal desorption (TD) coupled with thermal oxidation (TO). TD/TO is a mobile and scalable treatment solution that can be implemented onsite at a significantly lower cost than conventional off-site incineration or landfill disposal options (Project Overview).
• Dr. Stephen Richardson from GSI Environmental Inc. will lead the demonstration and validation of an integrated treatment approach that uses nanofiltration to concentrate PFAS and co-occurring chemical-impacted water combined with electrical discharge plasma to treat the concentrate derived from nanofiltration. Nanofiltration has proven to be less energy intensive than other membrane technologies, and plasma generates no waste and offers more cost savings than granular activated carbon (GAC) and off-site incineration (Project Overview).
• Dr. Charles Schaefer at CDM Smith and his team will assess analytical tools in relation to their ability to provide information related to PFAS mass discharge, perfluoroalkyl acid formation potential, and organic fluorine mass balance. The team will perform in-depth groundwater analyses at several AFFF-impacted DoD sites (Project Overview).
• Dr. David Adamson at GSI Environmental Inc. will develop a framework for using monitored natural attenuation (MNA) at PFAS-impacted sites. The project team will compile and summarize all key processes that can attenuate PFAS plumes in groundwater. A goal of this project is to determine if certain sites could be managed by MNA (Project Overview).
• At Haley & Aldrich, Dr. John (Zhong) Xiong and his team will demonstrate a cost-effective and sustainable chemical reductive technology for on-site destructive treatment of PFAS in a concentrated waste stream. The technology is primarily based on hydrated electrons generated in an ultraviolet (UV)/sulfite system, which have shown to be effective in degrading PFAS (Project Overview).
• Dr. Chadi El Mohtar at the University of Texas, Austin and his team will validate the use of jet grouting with modified clays for in situ PFAS source zone stabilization. Modified clays have yet to be implemented at large scale for PFAS, but recent efforts have shown successful application of modified clays to stabilize PFAS in bench-scale simulations as well as a small-scale field trial (Project Overview).

Collectively, these new projects are advancing technologies and approaches for managing PFAS-impacted sites. To learn more about SERDP and ESTCP’s PFAS research and demonstration efforts, visit the SERDP and ESTCP website.