Removing Forever Chemicals

Scientists first developed PFAS, or per- and polyfluoroalkyl substances, in the 1940s. Over the decades, the substance would be used in cookware, firefighting foam, textiles, paper products and have applications in photographic imaging, semiconductors, automotive manufacturing, construction, electronics and aviation industries.

In the late 1990s and 2000s, however, researchers began finding links to PFAS and adverse health effects, including:

• Increased cholesterol levels
• Decreased vaccine response in children
• Changes in liver enzymes
• Increased risk of high blood pressure or pre-eclampsia in pregnant women
• Small decreases in infant birth weights
• Increased risk of kidney or testicular cancer

Federal regulators began a push toward further studying and regulating these compounds, called forever chemicals because of their persistence in the environment. That effort has picked up pace over the last few years, and experts believe process manufacturers likely will be subject to some of these guidelines.

In February of 2019, the EPA released an action plan with the purpose of better identifying and understanding PFAS, addressing current PFAS contamination, preventing future contamination, and effectively communicating with the public about the compounds. Included in the action plan were six major regulatory steps for the agency:

1. Propose a supplemental significant new use rule (SNUR), which ensures EPA is notified before anyone begins or resumes the import of long-chain PFAS chemical substances as part of surface coatings on articles.
2. Explore data for listing PFAS chemicals to the Toxics Release Inventory.
3. Propose a drinking water regulatory determination.
4. Monitor PFAS in drinking water.
5. Explore industrial sources of PFAS that may warrant potential regulation.
6. Continue the regulatory process for a hazardous substances designation.

A Government Accountability Office report released in January of this year found that the EPA completed the first three of the planned actions and that the remaining three are ongoing.

The regulation of industrial sources of PFAS came a step closer in November 2020 when the EPA issued an interim guidance suggesting that PFAS should be limited in effluent water.

“That was a big signal to the industry that you’re probably going to have regulations in your permits coming up and you should start thinking about how to get that under control,” said Allyson Cunningham, a partner at Lathrop GPM in the environmental and tort practice group.

Whatever limits the EPA ultimately assigns, that still leaves process manufacturers with the question of how to get rid of forever chemicals.

“There are ways to get PFAS out, but by its nature it’s an ubiquitous compound. So it’s hard to get out,” Cunningham said.

There’s granular activated carbon. Cunningham said that method is effective, but not economical in many instances.

“It’s way too expensive, and you would be replacing the carbon filter or the grain on the carbon every day,” she said.

3M has played a major role in the country’s PFAS story. In the 1950s, 3M launched several products based on PFAS, including Scotchgard. In February 2018, the company pledged $580 million to settle a suit from the state of Minnesota over damage to the drinking water and natural resources caused by the company’s production of the chemicals. The company also ceased production of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) starting in 2000 and has led efforts to research PFAS and share best practices on detection, measurement and remediation of the compounds.

Dr. Rebecca Teeters is a senior vice president for fluorochemical stewardship at 3M.

Teeters said some advanced treatment technologies can be cost prohibitive for some operations, but for 3M, carbon was an optimum solution. Part of the reason is because the method is ideal for targeting PFOA and PFOS — two compounds that regulators have historically focused on reducing.

Another method for removing PFAS from water is ion exchange resin. Teeters said one benefit of ion exchange is that the process can be tailored for particular species of PFAS.

Methods such as reverse osmosis and solidification show promise and are more cost effective, Cunningham said, “but until I see the data on it, I would have my doubts on how successful it really is in removing a lot of PFAS. You don’t want to be removing half of it, you want to remove as much as you can.”

There are also nanofiltration methods and Cunningham said those are somewhat effective, but it still leaves some PFAS in the water. And with the limits from the federal government still undetermined, she said, “I think I would be somewhat hesitant as a discharger right now to invest in a treatment technology until I know exactly what level of treatment I really need to get down to [in order to] get the PFAS removed.”

There’s also the question of what to do with PFAS once they’re removed. With most treatment methods, processors are left with a byproduct. The EPA issued guidance for this in December 2020.

“If you boil it down, they basically said, ‘We still don’t know what to do with this.’ Their main suggestion was interim storage,” Cunningham said.

Issues may develop if the EPA designates PFAS as a hazardous substance under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). “It would be a game changer in a lot of ways,” Cunningham said.

CERCLA is intended to address past historical contamination. According to Sarah Lintecum, an associate at Lathrop GPM who focuses on insurance coverage and environmental law, adding PFAS to that designation would suddenly change the status of many sites that have been cleaned up under the standards of current law.

Lintecum said many manufacturers would find themselves asking, “Do we have to look it up again, and add more parties and clean it up to a higher standard?”

A hazardous substance designation would make property owners responsible for remediation even if the contamination occurred well before they owned the land.

Lintecum said companies that are looking into PFAS should check their historical records for insurance policies purchased before 1973. After that year, insurance companies began placing pollution exclusion clauses that restricted coverage on sudden and accidental pollution events. Having those pre-1973 policies could help companies dealing with legal claims from neighbors or regulators.

PFAS Disposal

Cunningham said there are three methods for disposal of PFAS: deep well injection, landfills and incinerations, “none of which is a perfect solution for a variety of reasons,” Cunningham said. But according to Teeters, there’s a lot of work being done for novel destruction methods.

The Battelle Memorial Institute, a private nonprofit applied science and technology company, has recently developed such a method. Battelle’s PFAS Annihilator Destruction Technology is a closed-loop, on-site destruction solution powered by supercritical water oxidation.

For the past three years, Battelle has made a corporate investment in developing solutions for PFAS. Chemist Amy Dindal has been leading that effort.

Dindal said the Annihilator destroys PFAS down to non-detectable levels in the water. She said supercritical water oxidation isn’t a new technology. It’s been used for chemical weapons and polychlorinated biphenyls or PCBs, but Battelle adapted it to work for PFAS.

Dindal said that one of the reasons Battelle was able to successfully develop the Annihilator is because of its investments in PFAS analytical techniques. The group has an accredited lab that performs about 25,000 samples a year. Battelle has also developed advanced analytical methods which detect nearly 500 PFAS.

“The awareness comes from the increase in monitoring and measurement methods in order to be able to detect compounds and to detect them in lower concentrations,” she said.

Teeters said process manufacturers looking to address PFAS must do the hard work of engaging in the science of these materials to find the right solution for their specific cases.

“There is no one size fits all solution to this," she said. "It requires detailed study, complex engineering and a great amount of investment to truly understand the details of every site and make certain we’re respecting that engineering complexity." WT

Daniel Gaddy is editor of Water Technology. With a bachelor's and master’s degree in journalism from the University of Alabama, Gaddy spent 10 years as a reporter and editor for community newspapers in Alabama before joining Water Technology’s parent company, Endeavor Business Media.