We’re proud to share a new publication in "Water Research": "Characteristics of aqueous film forming foam (AFFF) sites impacted with per- and...
We’re proud to share a new publication in “Water Research”: “Characteristics of aqueous film forming foam (AFFF) sites impacted with per- and polyfluoroalkyl substances (PFAS): A 37-site study.”
Co-authored by Poonam Kulkarni, PE, Abigail Cartwright, PE, David T. Adamson, PhD, PE, John Cook, EIT, and Charles J. Newell, PhD, PE, BCEE of GSI, along with Nicolette E. Andrzejczyk and Arun Gavaskar, this article provides insight into PFAS concentration patterns in soil and groundwater at AFFF source zones across the U.S.
Key findings include:
• PFOS and PFOA are the primary contributors in soil, while groundwater concentrations show broader variability
• Maximum PFAS concentrations typically occur in the top one meter of soil
• Median inferred plume lengths for the seven PFAAs range from 220–800 meters
• PFOS, PFOA, and PFHxS contribute 99% of the estimated groundwater exceedance magnitude
Read the full paper about Aqueous Film Forming Foam (AFFF) sites impacted with per- and polyfluoroalkyl substances (PFAS) here: https://www.sciencedirect.com/science/article/abs/pii/S0043135425010310
We’re proud to share a new publication by GSI’s Graham K. Ansell, PhD and Hassan Javed, PhD titled "PFAS Analytical Methods – A Practical Guide," available...
We’re proud to share a new publication by GSI’s Graham K. Ansell, PhD and Hassan Javed, PhD titled “PFAS Analytical Methods – A Practical Guide,” available in the “Journal of Fluorine Chemistry.”
As PFAS science advances, so does the need for accurate and reliable analytical methods. This article offers a practitioner-focused overview of current PFAS methods, from EPA’s promulgated methods to screening methods, highlighting the strengths, limitations, and key considerations of each.
Whether you’re experienced in PFAS analytical methods or just starting to explore the challenges of PFAS analyses, this guide is a valuable resource for informed decision-making.
Read the full article here: https://www.sciencedirect.com/science/article/abs/pii/S0022113925000569
Just published! "PFAS Monitored Retention: A Framework for Managing PFAS-Contaminated Groundwater Sites" is now available in “Groundwater Monitoring & Remediation.” Co-authored by...
Just published! “PFAS Monitored Retention: A Framework for Managing PFAS-Contaminated Groundwater Sites” is now available in “Groundwater Monitoring & Remediation.” Co-authored by GSI’s David T. Adamson, PhD, PE, Charles J. Newell, PhD, PE, and Poonam Kulkarni, PE, alongside collaborator Hans Stroo, the article introduces PFAS Monitored Retention (PMR) as a scientifically sound, cost-conscious approach to managing PFAS at groundwater sites.
The framework builds on the principles of monitored natural attenuation (MNA), expanding the toolbox for site managers by emphasizing retention processes like sorption, matrix diffusion, and precursor retention, particularly when immediate risk to receptors is low.
Read the full open-access article here: https://ngwa.onlinelibrary.wiley.com/doi/10.1111/gwmr.70001
GSI has developed a new state-of-the-science calculator to explore Fish Consumption Advisories (FCA) for PFOS and other contaminants! FCAs are a public...
GSI has developed a new state-of-the-science calculator to explore Fish Consumption Advisories (FCA) for PFOS and other contaminants! FCAs are a public health tool used by states to guide public fish consumption – acceptable meal frequencies and fish species – on specific water bodies. GSI conducted a state-by-state survey and identified 17 states that have issued a PFOS advisory on at least one water body. We created the FCA tool to answer frequently asked questions from a range of stakeholders, including consumers, state regulators developing new advisories, and risk assessors who would like to explore the sensitivity of advisories to alternative exposure factors and toxicity values. Use this tool to answer these questions and more:
1. Given a measured concentration in fish (fillet), what is a safe number of fish meals per month?
2. What are the different meal frequencies used to set advisory levels in my state?
3. How do states compare? Do they have different advisories for the same measured concentration in fish?
4. Is a different advisory recommended for women of child-bearing age or children?
5. How would the advisory level change if there is a change in the toxicity value?
6. How would the advisory change when calculations are conducted with personalized variables for body weight and meal size?
7. What are the inputs used by my state – can I reproduce the advisory level exactly?
8. Which water bodies currently have existing FCAs for PFOS in my state?
9. Who is the point of contact at the state level who can answer more questions?
Technical documentation is provided including detailed equations, inputs, and state-specific information, all in one convenient accessible library.
GSI will continue to update the tool to keep pace with the rapidly changing science and regulatory landscape.
Explore the Fish Consumption Advisory calculator now at gsienv.com/fish-advisory-calculator. Have questions? Our experts are here to help.
GSI is honored to be ranked #25 on Zweig Group's 2025 Hot Firm List, a major leap from last year’s #74 ranking. This...
GSI is honored to be ranked #25 on Zweig Group‘s 2025 Hot Firm List, a major leap from last year’s #74 ranking. This prestigious list recognizes the 100 fastest-growing AEC firms in the U.S. and Canada that are setting the pace through strategic growth, operational excellence, and innovation.
Climbing nearly 50 spots in just one year is a reflection of the incredible work of our team, our trusted partners, and the clients who inspire us to keep pushing forward.
We’ll be celebrating with our peers at the 2025 ElevateAEC Conference & Awards Gala in San Antonio this September. We hope to see you there!