In this webinar, guest speaker Rick McGregor, President of InSitu Remediation Services Ltd. discusses the details of a series of pilot-scale field studies he has carried out, to evaluate different in situ remedial approaches to treat PFAS in groundwater.

The pilot-scale field studies comprise the use of two chemical oxidants: hydrogen peroxide and sodium persulfate; as well as four adsorbents: Powdered Activated Carbon (PAC), Colloidal Activated Carbon (CAC) (this is our product PlumeStop), Ion-Exchange Resin (IER) and Biochar. The results of this work has recently been published in Wiley’s Remediation journal.

Various PFAS were detected within the pre-treatment groundwater including PFDS, PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFOS and PFNA with concentrations ranging up to 18,000 ng/L for PFPeA. Six pilot-scale permeable reactive zones (PRZs) were created in a shallow, unconfined aquifer situated in a slightly saline, sulfate-iron reducing environment. The groundwater was also impacted with gasoline-range petroleum hydrocarbons along with various additives including MTBE and TBA.

Rick is joined by Maureen Dooley, Director of Strategic Projects at REGENESIS, who discusses in situ treatment of PFAS using colloidal activated carbon to eliminate PFAS risk at a low cost.

Key points discussed in this webinar:

  • Comparisons will be made of reagent distribution across the injection depth, showing CAC and persulfate distributed most uniformly.
  • Discussion will be made of disproportionate amounts of PAC and Biochar enter the monitoring well packing and how this may affect results.
  • Chemical oxidation appears ineffective on PFAS.
  • PAC, IER and Biochar show initial reductions in concentrations, followed by contaminant break-through.
  • Only CAC shows sustained treatment, with all PFAS constituents remaining at ‘non-detect’ for 550 days of monitoring.
  • Case studies will show application approaches and actual results.
  • Future projects and ongoing academic studies in partnership with 3 universities.


About the presenters:

Rick McGregor
President | InSitu Remediation Services Ltd.

Rick McGregor has over 26 years’ experience in groundwater and soil assessment and remediation. He has worked in over 30 countries and has authored numerous papers on groundwater assessment and remediation. Rick holds a MSc from the University of Waterloo in hydrogeology and geochemistry and is a Certified Ground Water Professional in Canada and the United States.


Maureen Dooley
Director of Strategic Projects| REGENESIS

Maureen Dooley has over 25 years’ experience in the environmental industry including project management, research and development, senior technical oversight, remedial design and laboratory management. Ms. Dooley’s current position is the Director of Strategic Projects at REGENESIS. In her role she provides technical leadership for complex soil and groundwater remediation projects across North America, as well as remediation design, strategy and business development throughout north-eastern United States and eastern Canada. As part of her responsibilities she has reviewed hundreds of projects and provided recommendations for remediation. In addition, she has completed numerous treatability studies designed to evaluate the remediation of a wide range of contaminants, including chlorinated solvents, petroleum hydrocarbons, and emerging contaminants like PFAS.

Watch webinar recording