This pre-conference workshop is sponsored by Porewater Solutions, and is being offered in partnership with the 2025 RemTEC & Emerging Contaminants Summit in Westminster, Colorado. 

Date: October 13, 2025
Time: 2 to 5 pm MT
Location: Westminster, Colorado

Abstract: This interactive workshop explores practical tools and real-world case studies for understanding and treating per- and polyfluoroalkyl substances (PFAS) in groundwater. Participants will learn about visualization methods for PFAS site characterization, remediation, and forensic assessments. The workshop includes hands-on training exercises using Visual PFAS™ Lite, a free software tool that will be provided to participants for evaluating PFAS precursor transformations, characterizing plume behavior, comparing background to potential site impacts, and communicating findings to stakeholders.  Participants will also learn about in-situ remediation using colloidal activated carbon, supported by lessons from Department of Defense research programs, including the Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP). This workshop is designed for consultants, regulators, and groundwater professionals involved in PFAS site planning, analysis, and cleanup.
Case studies used to demonstrate visualization and modeling methods include:

• South Dakota AFB – Forensic assessment differentiating between types of AFFF products used in known source areas; use of PFAS ratios to visualize precursor  transformation to PFAAs; visualization of spatial trends in TOP assay results overlaid on a site map; and visualization and modeling of PFAS transport in the vadose zone based on prior lysimeter sample results.
• Michigan Air Force Base – Radial diagram and stacked bar mapping methods used to clearly differentiate between PFAS fingerprints in groundwater, porewater, and surface water samples collected downgradient from a former fire training area.
• East Coast Site – Visualization and high-resolution modeling of a two-year PlumeStop® pilot test.

The main goal of this workshop is to provide participants with the knowledge and tools for developing PFAS site work plans, evaluating site data, preparing feasibility studies for evaluation of in-situ PFAS remediation, and to effectively communicate the results of these analyses to project stakeholders.  Free visualization software (Visual PFAS™ Lite) will be provided to all participants ahead of the course for use in hands-on exercises during the workshop.  (See www.porewater.com/VisualPFAS-Lite.html for more information on this free software tool.)

Click here to register for this conference

Downloadable case studies discussed in this workshop include:

• PFAS Visualization at South Dakota AFB (2025)
• CAC remedy feasibility study (2024)
• Coastal site modeling of CAC performance for PFAS in-situ remediation (2024)
• Evaluating placement options for a CAC barrier at an AFFF-impacted site (2023)

Workshop Outline

• Introduction to PFAS
• PFAS primer
• General PFAS sources and background conditions
• Precursor transformations to PFAAs
• AFFF product composition
• PFAS transport and use of lysimeters in the vadose zone
• Overview of federal and state regulations

• PFAS Visualization Case Studies
• South Dakota AFB
• Michigan AFB
• Several case studies with forensic applications including a review of linear vs branched, use of precursor:PFAA ratios to identify evidence of transformation, and visualization approaches for evaluating relative AFFF product use in different source areas
• Hands-on exercises with the free Visual PFASTM Lite software tool provided to workshop participants

• Overview of PFAS Vadose Zone Transport and Modeling
• PFAS transport concepts in the vadose zone
• Goals and methods for estimating PFAS mass discharge from the vadose zone to an underlying aquifer
• Detailed case study review of PFAS in shallow and deep lysimeters and in underlying groundwater
• Comparison of various analytical and numerical models to quantify PFAS mass discharge and attenuation in the vadose zone including Dr. Bo Guo’s new PFAS LEACH model which is freely available

• PFAS In-Situ Remediation Using Colloidal Activated Carbon (CAC)
• Field-scale adsorption isotherms and effects of competitive sorption
• Several modeling and visualization case studies to demonstrate the results of a successful field-scale pilot test, evaluation of the optimal placement of a CAC barrier, the influence of coastal site properties on CAC remedy performance, and a detailed CAC remedy feasibility study.

Learning Objectives: After this workshop, participants will be able to:

• Identify precursors in groundwater that may biodegrade to regulated PFAS under aerobic or anaerobic conditions at your sites.
• Match applicable visualization methods with site-specific PFAS needs
• Use free Visual PFASTM Lite software to assess inter-relationships between various PFAS for the purpose of assessing precursor transformations, plume attenuation along a flow path, TOP assay results, remediation performance, and forensic differentiation of source contributions to a commingled plume.
• Identify the goals of estimating PFAS mass discharge in the vadose zone and list several available models for predicting PFAS vadose zone transport.
• Explain at least four site factors which influence the longevity of colloidal activated carbon barriers for in-situ PFAS remediation.
• Describe three to five site characterization activities recommended for sites where in-situ PFAS remediation will be considered as a site remedy.
• List at least two to three lessons learned from SERDP-ESTCP projects related to the in-situ remediation of PFAS in groundwater using colloidal activated carbon.

Biography: Grant Carey, Ph.D. is President of Porewater Solutions. Grant has more than 30 years of experience specializing in PFAS fate and transport; site characterization and remediation; DNAPL delineation; groundwater modeling; environmental forensics; and mining water management. Grant is currently involved with seven SERDP and ESTCP projects for the U.S. Department of Defense with a focus on PFAS remediation, and most recently the development of PFAS e-learning modules. Grant has developed a proprietary reactive transport model for evaluating PFAS fate and remediation (In-Situ Remediation i.e., ISR Model), and Grant is co-developer of the Visual PFASTM software tool. Grant is also an Adjunct Research Professor at Carleton University and an Adjunct Professor at the University of Toronto.