3M offers $10.3 billion in compensation over PFAS contamination in water systems

3M offers $10.3 billion in compensation over PFAS contamination in water systems

PFAS chemicals seemed like a good idea at first. As Teflon, they made cleaning pots easier from the 1940s onwards. They made jackets waterproof and carpets dirt-repellent. Food packaging, firefighting foam, and even makeup appeared to perform better with perfluoroalkyl and polyfluoroalkyl substances.

Then tests began to detect PFAS in people's blood.

Today, PFAS are widespread in soil, dust and drinking water around the world. Studies suggest they are found in 98% of Americans' bodies, where they are linked to health problems such as thyroid disease, liver damage, and kidney and testicular cancer. There are now over 9,000 types of PFAS. They are often referred to as “forever chemicals” because the same properties that make them so useful also ensure that they do not break down in nature.

Industrial giant 3M, which has manufactured PFAS for many uses for decades and has faced lawsuits over PFAS contamination, announced a $10.3 billion settlement with public water utilities on June 22, 2023 to help fund testing and treatment. The Company assumes no liability in the settlement, which requires court approval. The cleanup could cost many times that amount.

But how do you capture and destroy an eternal chemical?

Biochemist A. Daniel Jones and soil scientist Hui Li work on PFAS solutions at Michigan State University and explained the promising techniques being tested today.

How do PFAS get from everyday products into water, soil and ultimately into people?

There are two main routes of exposure through which PFAS enters humans: drinking water and food consumption.

PFAS can enter the soil through the land application of biosolids, i.e. sludge from wastewater treatment, and leach from landfills. When contaminated biosolids are applied to agricultural fields as fertilizer, PFAS can leach into water and into crops and vegetables.

For example, livestock can absorb PFAS through the plants they eat and the water they drink. Cases of elevated PFAS levels in beef and dairy cows have been reported in Michigan, Maine and New Mexico. The extent of the potential risk to humans is still largely unknown.

Scientists in our research group at Michigan State University are working on materials that could be added to soil and prevent plants from absorbing PFAS, but would leave PFAS in the soil.

The problem is that these chemicals are everywhere and there is no natural process in the water or soil that effectively breaks them down. Many consumer products are loaded with PFAS, including makeup, dental floss, guitar strings and ski wax.

How do remediation projects eliminate PFAS contamination now?

There are methods to filter them out of the water. The chemicals stick to activated carbon, for example. However, these methods are expensive for large projects and you still have to do without the chemicals.

For example, near a former military base near Sacramento, California, there is a huge activated carbon tank that takes in about 1,500 gallons of contaminated groundwater per minute, filters it and then pumps it underground. This cleanup project cost over $3 million, but it prevents PFAS from entering the drinking water used by the community.

The U.S. Environmental Protection Agency has proposed establishing legally enforceable requirements for maximum levels of six PFAS chemicals in public drinking water systems. Two of these chemicals, PFOA and PFOS, would be recognized as individual hazardous chemicals, with regulatory action enforced if levels of any of these chemicals exceed 4 parts per trillion, well below previous guidance.

Filtering is just one step. Once PFAS is captured, you must dispose of PFAS-laden activated carbon, and PFAS continues to move. If you bury contaminated materials in a landfill or elsewhere, PFAS will eventually leach out. That's why it's important to find ways to destroy it.

What are the most promising methods scientists have found to break down PFAS?

The most common method of destroying PFAS is incineration, but most PFAS are remarkably resistant to incineration. That's why they are included in firefighting foams.

PFAS has multiple fluorine atoms bonded to one carbon atom, and the bond between carbon and fluorine is one of the strongest. To burn something you usually have to break the bond, but fluorine cannot be separated from carbon. Most PFAS completely decompose at combustion temperatures around 1,500 degrees Celsius (2,730 degrees Fahrenheit), but it is energy intensive and suitable incineration facilities are rare.

There are several other experimental techniques that show promise but have not been expanded to treat large quantities of the chemicals.

A group in Battelle has developed supercritical water oxidation to destroy PFAS. High temperatures and pressures change the state of water and accelerate chemistry in ways that can destroy dangerous substances. However, scaling remains a challenge.

Others work with plasma reactors that use water, electricity and argon gas to break down PFAS. They are fast, but also not easy to scale.

What are we likely to see in the future?

Much will depend on what we learn about where most human exposure to PFAS comes from.

If exposure occurs primarily through drinking water, there are other methods with potential. It is possible that it will eventually be destroyed at the household level by electrochemical methods, but there are also potential risks that remain to be understood, such as the conversion of common substances such as chloride into more toxic byproducts.

The big challenge in remediation is to ensure we don't make the problem worse by releasing other gases or creating harmful chemicals. Humans have long tried to solve problems and make things worse. Refrigerators are a good example. Freon, a chlorofluorocarbon, was the solution to replace toxic and flammable ammonia in refrigerators, but then it caused ozone depletion in the stratosphere. It has been replaced by fluorocarbons, which now contribute to climate change.

If there is a lesson to be learned, it is that we need to think through the entire life cycle of products. How long do we really need chemicals to last?

This is an updated version of an article originally published on August 18, 2022.

A. Daniel Jones, Professor of Biochemistry, Michigan State University and Hui Li, Professor of Environmental and Soil Chemistry, Michigan State University