PFAS were a component of aqueous film-forming foams used to fight liquid fuel fires
Source: National Archives, US Air Force (USAF) Fire fighters with the 167th Air Wing (AW), West Virginia Air National Guard (WVANG), quench a simulated aircraft fire during a training session
Per- and polyfluoroalkyl substances (PFAS) are called "forever chemicals" because the molecules are so tightly bonded that natural degradation occurs very slowly. There are 12,000 chemicals in the PFAS group.
PFAS were used in manufacture of stain and water repellent material, food packaging and other consumer products, plus fire-fighting foam. A detectable level of PFAS is estimated to be present in 45% of drinking water supplies in the United States, ranging from 8% in rural area served by wells to 70% in urban areas drawing water from lakes and rivers.1
PFAS molecules form "forever chemicals" because bonds between atoms are especially strong and thus slow to break apart
Source: Wikipedia, Sustancias perfluoroalquiladas
By 2015, at last one of 32 types of PFAS were found in the blood of 95% of Americans. The health effects were not fully understood, but researchers were targeting cancers, delayed development of children, and fertility impacts. At last 75% of tap water tested in urban areas had a last one form of PFAS. In rural areas, 25% of drinking water systems were contaminated.2
In 2023, the Environmental Protection Agency (EPA) proposed drinking water standards to limit PFAs to no more than 4 parts per trillion:3
in 2024, finished drinking water sold to customers from Fairfax Water's Griffith Treatment Plant exceeded new EPA standards for PFOA starting in 2029
Source: Fairfax Water, Facts About PFAS
Also in 2023, DuPont de Nemours Inc., the Chemours Company and Corteva Inc., settled a class action lawsuit and agreed to pay $1.2 billion for PFAS contamination in some drinking water systems. Separately, 3M agreed to pay $10.3 billion to provide funding for public water suppliers to test for PFAS and remove the chemicals.4
The technologies to remove PFAS from drinking water were still in early development stages. Options included activated carbon adsorption, ion exchange resins, and high-pressure membranes. Without a clear understanding of the investment required, 4,100–6,700 suppliers of public drinking water with high levels of PFAS had to speculate on the future costs to meet the proposed 4 parts per trillion standard.
The cost was justified by increasing protection of human health. Acccording to the Environmental Potection Agency (EPA):5
PFAS molecules can be removed through hybrid membrane filtration and photocatalysis
Source: Journal of Hazardous Materials, PFAS and their substitutes in groundwater: Occurrence, transformation and remediation (June 15, 2021)
Drinking water is just one avenue for humans to ingest PFAS. In 2024, manufacturers of food packaging agreed voluntarily to stop using PFAS, which made hamburger wrappers and salad containers more oil-resistant. One university professor noted that the action by the manufacturers was significant in part because it limited PFAS exposure where consumers were unlikely to take action, because:6
The Environmental Protection Agency (EPA) finalized its proposed rule for limiting per- and polyfluoroalkyl substances on April 10, 2024. It was the first rule to deal with a new drinking water contaminant since 1996.
The Federal agency estimated the lower limits would reduce PFAS exposure for approximately 100 million people. The new rule forced drinking water suppliers, including public utilities, to clean up waste that others had put into waterways. Federal action was directed towards reducing the risks to drinking water customers rather than eliminating the discharge of PFAS, or the cleanup of sies leaking "forever chemicals" into water supplies.
The Environmental Protection Agency did announced the availability of $1 billion from the Bipartisan Infrastructure Law to fund implementation by the 6-10% of the 66,000 public drinking water systems that would have to take action. Technologies to reduce PFAS in drinking water included granular activated carbon, reverse osmosis, or ion exchange systems.7
In April 2024, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were designated by the Environmental Protection Agency as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). That designation made major chemical manufacturers and users as potentially responsible for the costs of removing the two chemicals in Superfund cleanup projects.8
When the Virginia Department of Health tested a sample of the 2,860 public water systems in the state, over 6% (18 out of 274) exceeded the threshold.9
Costs to remove PFAS chemicals from drinking water supplies will be significant. The Fauquier County Water and Sanitation Authority calculated that PFAS levels exceeded the new Environmental Protection Agency thresholds in 35% of the 46 public drinking water wells. The wells producing the most water had the greatest contamination, so 50% of the county's public drinking water exceeded the threshold.
The authority, which had $14 million in annual revenue from water and sewer fees, estimated that PFAS removal costs would require a capital investment cost of over $40 million. The chair of the Board of Supervisors said:10
The Virginia Department of Health (VDH) identified PFAS in drinking water samples. A separate state agency, the Virginia Department of Environmental Quality (DEQ), had responsibility for managing the waste that leaves drinking water and wastewater treatment plants.
As the larger wastewater treatment systems began to test for PFAS in the treated effluent, nearly all (20 out of 21) found PFAS in the water they discharged into streams.
All eight wastewater treatment plants that tested their sludge found PFAS. In 2022, Maine prohibited farmers from using sewage sludge on agricultural land in order to limit the potential of PFAS and other residues from entering the food chain. In Virginia, the Department of Environmental Quality (DEQ) chose to wait for Federal regulations.
In 2024, groups including the Potomac Riverkeeper and Public Employees for Environmental Responsibility (PEER) filed a lawsuit to force the Environmental Protection Agency to limit PFAS levels in sewage sludge used as biosolids on farm fields. The groups wanted EPA to take action beyond simply identifying sludge reuse as a potential problem.11