PFAS Frequently Asked Questions
Updated – December 2023
Note that current FAQs may supersede archived FAQ responses.
What is PFAS? PFAS (Perfluoroalkyl substances) are “forever chemicals” designed to be resistant to biological, chemical, and thermal breakdown. It is found in many products, such as non-stick pans, water repellant fabrics and applications, microwave popcorn, pizza boxes and even some brands of dental floss. It is also found in Aqueous Film Forming Foam (AFFF) which was previously mandated for use by some fire departments and at commercial service airports in the United States. Because PFAS is used in so many applications, most Americans have some level of PFAS in their bloodstreams.
PFAS comprises more than 10,000 individual man-made substances. Of these, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are two of the substances most commonly associated with AFFF.
Why is PFAS a problem? Several studies have linked PFAS exposure to health issues and more studies are underway to evaluate potential health effects. PFAS have not been classified by the USEPA as a hazardous substance or a carcinogen. However, in March 2023, the USEPA proposed to adopt enforceable Maximum Concentration Limits (MCLs) for PFOS and PFOA at 4 ppt each. Once the MCLs are finalized (anticipated 2024), public water supply systems will be required to meet the limits within three years.
Why is PFAS used at Airports? From the 1970s until September 2023, the Federal Aviation Administration (FAA) required all fire departments at airports served by airlines to use AFFF containing PFAS to extinguish aircraft fires. AFFF with PFAS was required by the FAA because at the time it was the only fire extinguishing agent that was stable and did not react with other chemicals, including jet fuel. AFFF extinguished fires by sequestering fuel sources from oxygen, thus preventing them from reignition.
With an understanding of the environmental and human health considerations of PFAS, an industry effort began in the late 2010s to find a fire extinguishing agent that could have the performance of AFFF but not contain PFAS. After extensive testing of potential firefighting foams by the FAA, in January 2023 the FAA announced that fluorine-free firefighting foams which do not contain PFAS could be used at airports served by airlines. It was not until September 2023 that the first fluorine-free firefighting foam was certified by the FAA for use at airports. Presently, airports have the option to use AFFF containing PFAS or fluorine-free firefighting foams to meet FAA requirements.
What is being done regarding AFFF use at airports nationally? In December 2022, Congress directed the FAA to develop a plan for airports to transition from using AFFF to a replacement firefighting foam (fluorine-free foam or F3) that did not contain PFAS. Even before this direction, in November 2022, the Jackson Hole Airport (“JAC”) had proactively developed a Fluorine-free Foam Transition Plan that outlined steps to promptly procure and transition to the use of F3, when it became available. On May 8, 2023, the FAA released the Aircraft Firefighting Foam Transition Plan which provided high-level guidance on concepts that airports should consider in developing a transition plan but did not include details on specific technical elements. JAC’s existing Plan was compatible with FAA’s recommended approach.
In January 2023, after extensive testing, the FAA announced that F3 could be used as a fire-extinguishing agent at airports served by airlines once products had been certified. In September 2023, the FAA certified the first F3 that could be used at airports. In anticipation of this announcement, JAC prepared to transition its fleet of firefighting vehicles for use of this new extinguishing agent. Once the announcement occurred in September 2023, JAC acquired the new certified F3 and completed its transition to the PFAS-free fire extinguishing agent in October 2023. Nationwide, airports now have the option to use AFFF containing PFAS or F3 to meet FAA requirements.
What has been done to minimize PFAS use at JAC? When JAC used AFFF, its fire department updated training practices several years ago to eliminate active sprays of AFFF. This included periodic tests required by the FAA to determine the product’s usefulness in which AFFF was contained during these tests and not released into the environment. JAC’s procedures after an emergency event were also revised to contain the spread of AFFF.
Once a fluorine-free foam (F3) that did not contain PFAS was certified for use at airports by the FAA in September 2023, JAC immediately acquired this product and transitioned its fleet of firefighting emergency response vehicles. The completion of this transition occurred in October 2023; thus, JAC no longer uses a fire extinguishing agent containing PFAS.
What more is being done to investigate PFAS at JAC? JAC works with environmental consultants who are experts in PFAS to determine where PFAS exists on and off the JAC airfield as a result of prior use of AFFF. We learned that PFAS does exist in some monitoring wells on JAC’s airfield and in domestic wells in surrounding areas.
JAC continues to work with the consultants to monitor both on- and off-airport water wells and to determine next steps for PFAS mitigation and remediation. The Jackson Hole Airport Board (Board) has committed to semi-annual (approximately February and August) testing for selected residences to monitor the plume’s migration off airport, in addition to semi-annual well testing on the JAC airfield.
Does my current drinking water filtration system work for PFAS? Many household filters, such as sand and granular activated carbon (GAC), are only partially effective at removing PFAS from drinking water.
Will the Board purchase a water filtration system for my domestic water well? JAC tested and found PFAS in some domestic water wells off the JAC airfield. In an exercise of caution the Board offered to purchase, upon request, point-of-entry treatment (POET) water filtration systems for all homes located with a defined Eligibility Boundary.
The Eligibility Boundary (EB), which has expanded over time based on changes in EPA advisories, defines an area where it is estimated that any concentration of PFOS or PFOA would be detected in groundwater, or in which PFOS and PFOA were detected. Residents whose parcels fall within the EB, or within an area in which PFAS is estimated to occur or has been detected, will be eligible to receive, at no cost to them, a whole-house domestic water filtration system that is certified to remove PFOS and PFOA. If any portion of a parcel is located within the EB, any domestic water well on the parcel will continue to be eligible for a filter. Water filters will be provided for domestic water wells only. It is the property owner’s responsibility to request installation of a filter system and to replace filters as indicated by system status lights. If a single residence requires more than one filter due to its size, additional system(s) will be provided and installed.
Will JAC continue to monitor any wells that have already been tested? Yes. JAC will continue to test a scientifically selected number of water wells both on and off the JAC airfield to better understand conditions with regard to seasonality and to track any changes over time.
What is a plume? Where is it and is it moving? A plume is a pattern of contaminant concentrations in groundwater that moves in the direction of the groundwater flow. Generally speaking, a plume is typically narrowest and most concentrated at the source of the contaminants. Concentrations may decrease and vary as it dissipates away from the source.
USGS, in conjunction with JAC, installed a series of groundwater wells on the JAC airfield in the early 2000s to evaluate water quality within the Snake River Aquifer. In February 2020, JAC voluntarily collected groundwater samples from these wells on airfield. These samples were tested for PFAS compounds, which were detected in several wells. Note that none of these on-airfield wells are drinking water wells.
A voluntary residential well testing program was started in April 2020 with domestic well water samples collected and analyzed for PFAS compounds. Three phases of voluntary residential testing were performed between April 2020 and February 2021. The results of the airfield well data and the residential well data allowed the scientists to plot the PFAS plume and determine areas (outside the EB) which have shown no detection of PFAS. The continued residential monitoring program began in August 2021. Its purposes are to (1) collect domestic well water samples, analyze them for PFAS, and compare the results to previous data; and (2) monitor the concentrations within the plume and along the non-detect EB boundary.
The PFAS plume is traveling in a southwesterly direction along a relatively fast-moving groundwater channel and appears to have retained its shape to date. As the groundwater moves through the source area, it picks up PFAS and transports it along the channel as it flows downstream. The plume diffuses as it encounters pathways with less resistance. In addition, groundwater flows and water depths vary with the seasons, which can affect not only the speed of groundwater flow but also how and where it disperses. As a result, we see concentrations vary at different locations in the plume with time, as well as distance from the source area, in ways that are difficult to predict.
JAC used FAA-mandated AFFF products historically for training and incident responses. The FAA restricted use of certain AFFF products at airports in 2019 and JAC complied by switching AFFF products. Once the FAA certified a fluorine-free firefighting foam for use at airports serving airlines in September 2023, JAC immediately acquired the product and completed the transition of its firefighting vehicle fleet in October 2023. As such, fire extinguishing agents containing PFAS are no longer used at JAC.
Continued monitoring of domestic water wells is showing decreases in results – why is this the case? The results at any well in the plume area depend not only upon the amount of PFAS remaining in the source area, but also the amount of groundwater flowing through the area and the pathways it is taking at any given time. Because groundwater is replenished by rainfall and snowmelt, the depth, flow rate, and path of groundwater are often affected by seasonal hydrology. Variability in concentrations is inherent in groundwater investigations and the long-term goal is a trend of decreasing concentrations. To date, the overall trend shows a decrease in the residential testing area.
Will the Airport continue to provide replacement filters? Upon request, the Airport currently provides replacement filters at no cost to residents that have had filtration systems installed through the airport program.
What if I purchase a home located within the Eligibility Boundary? Call Megan Jenkins, Communications Manager of the Jackson Hole Airport, at 307-699-4387.
Does seasonality play a major role in the fluctuating results? Because groundwater is replenished by rainfall and snowmelt, the depth, flow rate, and path of groundwater are often affected by seasonal hydrology. At this time, there has not been enough historical data collected to state definitively whether seasonality is a factor in fluctuating monitoring results. JAC will continue to sample wells and collect data with the goal of better understanding trends.
What does it mean if my test result is a “J” value or reading? See “Understanding Lab Results”.
Is the plume moving enough that the Eligibility Boundary (EB) will need to be expanded? JAC continues to compile data both inside and outside the EB. A new EB will be created if and as needed based upon the data. Residents will be notified if there are changes in the EB.
What are USEPA Regulations regarding PFAS? The US EPA’s interim lifetime health advisory (LHA) for drinking water was established in 2016 at 70 parts per trillion (ppt) for either chemical or the sum of the two. An LHA is based upon the following:
- An adult
- Weighing 70 kg (154 pounds)
- Drinking 2 liters/day (8.5 cups)
- From only the unfiltered house tap (no other water sources)
- For 70 years
- Concentration of PFAS is greater than the LHA (70 ppt combined PFOS and PFOA).
So, an average-size adult would need to drink at least 8 cups of water per day from the same unfiltered tap with PFAS concentrations above 70 ppt for a total of 70 years. A ppt, or part per trillion, is an extremely small measurement unit. In units of time, it would be 1 second in 32,000 years. The original lifetime health advisory of 70 parts per trillion equates to approximately 3.5 droplets of water in an Olympic size swimming pool (660,000 gallons). When these substances were found in groundwater near the JAC airfield, in an exercise of caution the Board offered to fund the installation of whole-house water filters where detection was at a 10 ppt or less – far more stringent than the 70 ppt LHA.
In June 2022, US EPA issued revised LHAs of 0.004 ppt for PFOA and 0.02 ppt for PFOS. These are 1,000 and 100 times, respectively, lower than the ability of current laboratory methods to detect. The Board responded by expanding its filter Eligibility Boundary to encompass all areas near the JAC airfield in which any amount of PFOA or PFOS were expected to be present.
It’s important to understand that these interim LHA concentrations are based on risk assessment analyses of toxicological studies. They are advisory concentrations and not enforceable requirements. As such, they do not reflect any consideration of feasibility or practicality relative to measurement, treatment or regulatory requirements and compliance.
In November 2022 and May 2023, USEPA issued Regional Screening Levels [(RSLs) for six PFAS compounds and an additional two PFAS compounds, respectively. For screening purposes until the MCLs are promulgated, the USEPA RSLs are used for on-airport water results from groundwater monitoring wells and domestic water wells. (Control Tower well is only drinking water well sampled as a part of semiannual monitoring activities). The RSLs are for a target hazard quotient (THQ) of 1.0. RSLs are not cleanup standards and are calculated using conservative exposure assumptions and available toxicity data.
In March 2023, the US EPA proposed to adopt enforceable Maximum Concentration Limits (MCLs) for PFOS and PFOA at 4 ppt each. Commercial laboratories using the current analytical methods can detect these compounds at 4 ppt. Certain treatment systems (including granulated activated carbon filters such as those funded by the Board) are already capable of removal of PFOS/PFOA at these proposed levels. If adopted, these proposed MCLs will supersede use of LHAs for comparing data collected from drinking water sources, such as the residential water wells.
EPA’s timeline for finalizing these MCLs into federally enforceable levels is as early as end of 2023 but could be as late as Fall 2024. Once the MCLs are finalized, public water supply systems will be required to meet the limits within 3 years.
JAC continues to monitor regulatory developments regarding PFAS, and will adapt testing, evaluation, and mitigation approaches accordingly. Currently, that includes using the concentration at which these chemicals can be detected in the laboratory as our threshold for mitigation via whole house water filtration systems on residential wells.
Why is the airport only talking about PFOA and PFOS when other PFAS substances have been detected in our water wells? PFOA and PFOS are the primary PFAS substances associated with AFFF formulations. They are also the two most studied PFAS substances amongst the 10,000+ PFAS class of substances.
Are there advisory levels for other PFAS chemicals? USEPA has not yet identified lifetime health advisory levels for several other PFAS substances in drinking water. Research studies are currently underway for dozens of PFAS substances, but it takes time for this research to generate enough data for USEPA to propose health advisories.
Do the filtration systems provided by JAC remove the PFAS substances that have been found in the water? The selected filtration systems are certified by NSF/ANSI (National Sanitation Foundation/American National Standards Institute) Standard 53 to remove PFOA and PFOS from water. PFOA or PFOS have not been detected in samples of water taken post-filtration system in off-airport wells, which is an indication that these filtration systems are indeed working. To date, NSF has certifications for only PFOA and PFOS. Other PFAS substances are probably removed using the same filtration system, but only PFOA and PFOS has thus far been certified for removal.
Why hasn’t USEPA or WDEQ set limits on all PFAS substances in drinking water? With a class of over 10,000+ substances, USEPA must select the substances which most likely represent a concern to human health and the environment. PFOA and PFOS were the first substances selected for evaluation and proposed health advisories in drinking water supplies. US EPA continues to add PFAS substances to its Unregulated Contaminant Monitoring Rule (UCMR), which can lead to setting drinking water standards. There are currently 35 PFAS substances in the UCMR process.
From where did the other PFAS substances found in the groundwater come? These other PFAS substances detected in groundwater samples collected during JAC investigations might have come from historic use of AFFF at JAC. They may be impurities introduced during the manufacture of AFFF formulations or they may be degradation (breakdown) substances from chemical, physical and biological processes in the environment. These may also have come from other sources. For instance, household plumbing may contain Teflon based plastics in the pipe, tape, or joint compounds, which contain PFAS.
What’s next? In determining our next steps locally, JAC remains in contact with Wyoming DEQ, the Teton County Health Department, the FAA and other agencies to stay up to date with the latest information regarding changes to regulations.
JAC’s number one priority is the safety of our operations – both for passengers and the surrounding community. Along with safety, JAC also makes environmental stewardship a vital part of everything The Airport does. The transition to F3 allows JAC to both enhance the safety of our passengers while limiting environmental impacts.
