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!
GSI has made the Zweig Group's 2024 Hot Firm List for the first time, ranking #74! This annual award recognizes the 100...
GSI has made the Zweig Group‘s 2024 Hot Firm List for the first time, ranking #74! This annual award recognizes the 100 fastest-growing AEC firms in the United States and Canada.
A huge thank you to our dedicated team and loyal clients for making this achievement possible. Here’s to continued growth and success!
Dr. Janet Anderson, PhD, DABT is among an international group of environmental consultants, regulators, land managers, and academics who have jointly published...
Dr. Janet Anderson, PhD, DABT is among an international group of environmental consultants, regulators, land managers, and academics who have jointly published an evaluation of differing approaches to regulation of per- and polyfluoroalkyl substances (PFAS) in Remediation.
A key conclusion was the recognition that neither a single-class approach nor a chemical-by-chemical approach is well suited to managing risks from PFAS at a contaminated site. Grouping PFAS in subgroups, while also focusing on a small number of the more hazardous “sentinel” PFAS, provides a balanced approach.
To read the full article, visit “Implications of grouping per- and polyfluoroalkyl substances for contaminated site regulation”.