A truck for Clean Harbors, a environmental and industrial cleanup service, parks near Picnic Pond on Aug. 22 during the cleanup process after the Aug. 19 toxic firefighting foam spill. Kristian Moravec / The Times Record

Brunswick Landing’s Aug. 19 spill of toxic firefighting foam was one of the worst in decades, renewing concerns about how the former Brunswick Naval Air Station could be cleaned — or if it could be at all.

The 1,450 gallons of foam concentrate mixed with 50,000 gallons of water that was released through a malfunctioning system at Hangar 4 contained PFAS, a family of thousands of chemicals known to be harmful to humans. Given the persistent and, at times, “invisible” nature of PFAS-containing materials, Maine scientists say that eradicating the “forever chemicals” is complex.

Christoph Aeppli, an environmental chemist for Bigelow Laboratory for Ocean Sciences, said that many challenges come with addressing PFAS, particularly if it’s spilled. He said that the chemical family is harder to see (if not in foam form), meaning that scientists have to test potentially contaminated materials quickly to make informed spill responses decisions. He added that PFAS chemicals are persistent because they do not naturally degrade from microorganisms like other contaminants, such as oil, can.

“In oil spills, you see the black oil floating on top of the water, and it oils a lot of organisms and shoreline and everything you see,” Aeppli said. “… for PFAS spills — in this particular case, it’s foam — we saw the foam floating around. But it disappears pretty quickly visually … so, that kind of makes it more challenging in a response perspective.”

Approaching PFAS cleanup also depends on the source contaminated. When it comes to cleaning drinking water, filtering PFAS out through carbon or resin filters is viable, Aeppli said.

Bigelow scientist Christoph Aeppli said that tackling PFAS contamination can be difficult given its sometimes “invisible” nature. PFAS can be hard to spot — unless it takes a foam form, as was seen at the Aug. 19 spill. Aeppli said this forces scientists to rely on quick testing to track where the contamination is spreading. Kristian Moravec / The Times Record

Based on the structure of PFAS compounds, the chemical family is both water soluble and hydrophobic, he said. But carbon is hydrophobic, meaning if you percolate water over a carbon filter, PFAS will likely stick to the carbon. Another method — for PFAS compounds smaller in chemical structure that are less likely to stick to carbon — is using ion-exchange resin.

“Both ways, basically, you have a filter media, you run water over it and then over time this gets saturated,” Aeppli said. “Then you need to remove, renew or cleanup somehow this filter media and regenerate it or burn it or replace it [to] filter some more water. This is a pretty proven method to get PFAS out of drinking water.”

When it comes to contamination of sediment and non-drinking water sources, the cleaning process is much more rudimentary and far from foolproof.

Percolation of contaminated water into ground water, for instance, can have long-term impacts. Sometimes the sediment can hold onto PFAS compounds, acting as a sponge taking up PFAS and releasing in a systematic fashion. The only option is to dredge the contaminated material and get rid of it, which can be costly. In the case of Brunswick Landing’s recent spill, Midcoast Regional Redevelopment Authority, a quasi-state entity, is footing the bill for the cleanup.

Aeppli said that cleaning PFAS from water sources like streams or ponds is difficult because these bodies can carry contaminants to other places, spreading the problem.

“When you say remediation, it’s all a matter of are we talking about remediating a home well, where you have some hundred gallons [of water] per day? Or are we talking about remediating a stream where you have thousands of cubic meters a day?” Aeppli said. ” … If we talk of big environment remediation, then it would be more dredging sediment out or just making sure through some engineering approach that the PFAS in the soil doesn’t move off-site by controlling the water or flow.”

Best treatment is prevention

Without some form of human intervention, PFAS cannot break down naturally in the environment. Aeppli added that just throwing a PFAS filter away in a landfill can be problematic, as the chemicals can leach from there to other areas. Currently, the chemical family can only be disposed of by incinerating it at high temperatures. Materials collected at Brunswick Landing are being shipped off-site to a facility in Texas capable of destroying PFAS using this method.

The best solution to PFAS contamination is prevention.

“They’re so persistent. As we saw in the Brunswick spill, if there are some tanks with PFAS sitting somewhere, it’s possible that they eventually end up in the environment,” Aeppli said. “So, the removal process and not producing more PFAS is really an important solution aspect.”

Onur Apul, an environmental engineer and scientist at the University of Maine, likened it to preventative medicine — it’s better to have healthy habits now to avoid problems down the line.

Apul also said that methods to address PFAS are developing rapidly, as people are creating new technology and studying more ways to counter PFAS.

Apul’s own research looks to address issues like PFAS with nanotechnology — which he describes as “using materials at atomic and molecular scale” — that cannot be resolved by conventional methods. For instance, he is researching whether it is possible to use nano-adsorbents to collect more PFAS in filter cartridges so that they can be changed less frequently.

Aeppli added that there is some potential research on microorganism that can breakdown certain PFAS compounds. He said a handful of microorganisms in sewage and sludge have been shown under certain conditions to reduce the concentration of PFOA and PFOS (types of PFAS) over time. While promising, he said this phenomenon is still being studied in lab-scale investigations and is not used in large-scale remediation efforts.

Apul said that the silver lining in growing PFAS concerns is that more people are putting resources together to address the problem. While he said that PFAS are a national and global crisis, those working to address it just need to stay the course.

“I am optimistic that we will be able to overcome this if we continue this path,” Apul said. “If we don’t deny that there is a significant public health issue and if we continue this path of resolving it by collaboration by putting our resources and will together, I think we can accomplish this.”