The PFAS Primer

GES PFAS Guide Cover

GES' Guide to Preparing for Successful PFAS Sampling, Analysis, and Treatment Selection

We know a lot more today about per- and polyfluoroalkyl substances (PFAS) than we did when these compounds first became recognized as contaminants of emerging concern in the early 2000s. Scientific research and advancements in technology have helped industry gain a better understanding of the potential contamination sources, human health risks, biological impacts, characterization methods, and treatment alternatives. As regulatory guidance of PFAS continues to evolve, there is a growing sense of uncertainty and urgency in both industry and the regulatory community.

We’re helping clients sharpen their understanding of the current science and regulatory landscape while taking proactive steps towards future compliance in the form of data collection, modeling, and treatment to address these potential risks. We share our perspective in the following post comprised of excerpts from the attached guide document available for download.  

What is PFAS?

PFAS is a family of more than 3,000 manmade fluorinated organic chemicals that have been produced since the mid-1900s. They are mobile, persistent, and, in some cases, bioaccumulative. PFAS are resistant to degradation in the environment, and when degradation occurs, it often results in the formation of other PFAS compounds.

What are the different PFAS compounds?

The PFAS family is comprised of thousands of compounds with markedly different physical and chemical properties. PFAS can be divided into a number of subgroups. The chart below illustrates the major PFAS classifications recognized by the scientific community. Currently, the key classes of concern are perfluoroalkyl carbolic acids (PFCAs) such as PFOA, and perfluoroalkyl sulfonic acids (PFSAs) such as PFOS. Other PFAS may transform in the environment through biological or geochemical processes to PFCAs and PFSAs.  

Figure 1. PFAS Family Tree
PFAS Family Tree Diagram

Where is PFAS found?

PFAS are manufactured globally and have been used in the production of a wide range of industrial and household products. Production of PFAS chemicals in the United States has been largely phased out over the last 20 years as health concerns have grown. Primary potential sources of PFAS releases are typically associated with a number of industries in the manufacturing sector as well as facilities that have historically stored and used Class B fluorine-containing firefighting foams, regularly referred to as Aqueous Film-Forming Foams (AFFF). Several waste streams, such as landfills and wastewater treatment plants, are considered potential secondary sources for PFAS release in the environment. The list of potential sources is expected to grow as more research is conducted and increased environmental sampling for PFAS occurs. 

Figure 2. Potential PFAS Sources
PFAS Industry Sources

How does PFAS affect me? 


You may have a PFAS concern if your facility used a PFAS-containing feedstock, produced PFAS materials, stored or transferred PFAS chemicals, handled or recycled containers that were used to store PFAS-containing materials, disposed of PFAS-containing waste or residuals, or used AFFF. PFAS can be introduced to the environment from spills, air emissions, and discharge of waters such as on-site wastewater treatment facilities.


As consumers, we have likely all been exposed to PFAS. While consumer sources such as water- and grease-repelling materials (e.g., rain coats, carpets, fast food wrappers, and pizza boxes) are often highlighted, exposure can occur through other means. Drinking water supply systems have been identified as PFAS exposure sources due to lack of appropriate treatment units and/or the recognition of the presence of PFAS. Wastewater treatment plants not designed to remove PFAS usually discharge to surface water. Biosolids from wastewater treatment plants are commonly land applied for agricultural use, which results in another potential exposure pathway.

Figure 3. Typical Life Cycle of PFAS in the Environment
Typical Life Cycle of PFAS in the Environment

Regulatory Status

The regulatory landscape surrounding PFAS continues to take shape at both the federal and state levels. Final regulations have not yet been promulgated for PFAS at the federal level. The United States Environmental Protection Agency (EPA) recently developed a Drinking Water Lifetime Health Advisory (LHA) of 70 parts per trillion for PFOA and PFOS (individual and combined), replacing previously-published provisional values. Several states including Minnesota, Maine, and New Jersey, have published screening values or interim criteria for one or more PFAS including PFOS, PFOA, perfluorobutanesulfonic acid (PFBS), perfluorobutanoic acid (PFBA), and perfluorononanoic acid (PFNA). The graphic below highlights the current standing of state-level regulation for PFOA and PFOS as of July 16, 2018.

Figure 4. Regulatory Status of PFOA/PFOS/PFNA in the United States (updated July 16, 2018; GES will periodically update the map as new information becomes available).
PFAS Regulatory Status Map as of July 16, 2018

Why GES?

GES has more than 30 years of hands-on experience developing and implementing sampling programs for the detection of emerging contaminants in air, soil, sediment, surface water, and groundwater. For the past 10 years, we have mobilized field crews at a high-profile site in support of a client investigation that includes routine sampling and reporting for more than a dozen PFAS compounds. We have successfully applied our unique project experience and approach to a number of PFAS sampling engagements across the country. GES has the equipment, resources, and trained personnel in place to mobilize crews for the safe and timely collection of field samples to ensure quality laboratory analysis, accurate regulatory reporting, and cost-effective plans for PFAS treatment and site remediation.

About the Author

Rich Evans is a Senior Vice President with overall responsibility for the firm’s technical practices in the areas of engineering, construction, hydrogeology, and drafting. He leads GES’ internal PFAS task force focused on developing internal best practices and transferring knowledge and lessons learned from GES’ PFAS experience across the country. Rich is an active member of the Interstate Technology & Regulatory Council (ITRC) PFAS team, contributing to the development of the Remediation fact sheet published in 2017.