Use of Site-Specific PFAS Batch Tests to Improve CAC Barrier Performance 

Date: Thursday, June 18, 2026, at 12:00 p.m. ET

Abstract

Colloidal activated carbon (CAC) in situ adsorption barriers have been widely demonstrated to be effective for mitigating the migration of plumes of per- and polyfluoroalkyl substances (PFAS) to groundwater, yet there are many details to consider when planning their use. The adsorption of PFAS of concern to CAC varies at each site depending on concentrations of dissolved organic carbon, co-occurring chemicals including precursors, geochemistry, ionic strength, and pH. In addition, adsorption isotherms can also vary substantially depending on where on the site the barrier is placed. Further, the cost and performance of a CAC barrier is strongly dependent on the PFAS adsorption isotherms used to model barrier longevity and design the injected carbon dose.  

In this webinar, you will learn about SiREM’s new service to estimate site-specific PFAS adsorption isotherms based on one or more groundwater samples collected at a site. Michael Healey and Grant Carey will address the benefits of conducting site-specific adsorption isotherms for designing a CAC barrier through case studies and modeling. They will also touch on recommendations and options for designing adsorption batch test programs and the modeling framework SiREM and EnSafe use to assess the feasibility of CAC barriers based on these PFAS adsorption isotherms.  

The Presenters

Grant Carey, PhDSubject Matter Expert, EnSafe
Grant is a Subject Matter Expert at EnSafe with more than 34 years of experience specializing in PFAS fate and transport, site characterization, and remediation; DNAPL delineation; groundwater modeling; environmental forensics; and mining water management. He is currently involved with seven SERDP and ESTCP projects focusing on PFAS remediation, and most recently, has helped develop PFAS e-learning modules. In addition, he has developed a proprietary reactive transport model for evaluating PFAS fate and remediation and is codeveloper of the Visual PFASTM software tool. Grant is an adjunct research professor at Carleton University and an adjunct professor at the University of Toronto.
Michael Healey Treatability Manager, SiREM
Michael is Treatability Manager at SiREM and offers more than 10 years of experience evaluating remediation technologies. He has managed numerous bench-scale studies that address remediation of contaminants, including chlorinated solvents, petroleum hydrocarbons, emerging contaminants, and other recalcitrant compounds in soil, sediment, and groundwater. He also offers experience with passive sampling and was a lead member in the development and commercialization of SiREM’s SP3™ sampler.