Department of Defense launches project to remove PFAS from naval base

374Water’s supercritical water process removes nearly 100 percent of PFAS contamination in materials.

A 374Water container sitting in a warehouse

Photo courtesy of 374Water

The National Defense Center for Energy & Environment (NDCEE), established to help transition technology solutions and meet sustainability goals in support of the Department of Defense (DoD), awarded Durham, North Carolina-based cleantech company 374Water a contract to use its supercritical water oxidation (SCWO), or “AirSCWO” technology, at U.S. Naval installations. The goal is to eliminate per-and polyfluoroalkyl substances (PFAS) from the environment.

Terms of the partnership length, base locations where equipment will be used and cost of the partnership were not disclosed.

“I think the industry has realized that when you incinerate materials that contain PFAS the elimination is not even close to complete,” says Kobe Nagar, the CEO of 374Water. “We are a big believer on the decentralized approach when you treat waste, processing it where it's being generated compared [with] moving it to a central location that is, in most cases, penalizing a disadvantaged community that is [located] next to [the processing plants].”

AirSCWO is a physical-thermal process powered by supercritical water, water above its critical point (374 degrees Celsius and 221 bar), and air that yields an effective oxidation reaction that eliminates organic compounds. 

Through a 40-foot container that can operate on-site, the material is pumped continuously through a reactor that gets superheated. The material then gets separated into a gas and liquid. The company captures the heat from the process and recirculates it into the process to heat the inlet streams that go to the reactor, making the process self-sustaining. On the back end, the remaining heat separates and evaporates some of the water into high-pressure gases, which are run through an expander to make electricity that can power auxiliary equipment. Nagar says one container can process six metric tons of waste per day.

Nagar says the process can remove almost 100 percent of PFAS contaminants. Once the process is completed, the machine produces nitrogen, Co2, and distilled or mineral-rich water, according to Nagar.

“What we have done is use that technology that can take any type of any type of organic waste and mineralize it in one step in creating clean water, energy and minerals from basically any type of waste,” Nagar says.

This project is part of a broader initiative by the DoD to identify viable PFAS destruction solutions for deployment on military bases. The effectiveness of AirSCWO to destroy PFAS has been demonstrated on PFAS-laden granular activated carbon and ion exchange resins, lime-stabilized sludges and Aqueous Film Forming Foam (AFFF).

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The company says this NDCEE project will validate the efficacy of AirSCWO to destroy PFAS in spent sorption media and ion exchange resins. Spent media and resins are generated during the treatment of PFAS-impacted water. High amounts of PFAS have been detected in the groundwater underlying hundreds of U.S. military bases. Much of this is due to the decadeslong use of AFFF for fire suppression and firefighting training.

Nagar says he and his partner Marc Deshusses, professor of Civil and Environmental Engineering at Duke University, began working on the system in 2013. The two began testing the filtering power of supercritical water until launching the company in 2018 with funding from the Bill and Melinda Gates Foundation. Since then, the company has developed clientele in North America, Western Europe and Israel.

“We wanted to think more holistically about waste,” Nagar says. “What we realized is that waste has a huge potential to be an energy source. One barrel of human waste can produce 87-kilowatt hours of electricity, roughly the size of the battery used in a Tesla T90.”

Recent action has been taken to mitigate environmental concerns associated with PFAS through conventional treatment and disposal methods such as incinerators and landfills. The 2022 National Defense Authorization Act (NDAA) prohibited the incineration of PFAS waste from DoD installations after 2022. The EPA has also proposed designating two of the most common PFAS compounds, perfluorooctanesulfonic acid and perfluorooctanoic acid, as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act. 

RELATED: US Composting Council calls to ban PFAS

"374Water is eager to work with the NDCEE as they collectively seek out sustainable environmental solutions for remediation efforts at scale," says Howard Teicher, senior director of government affairs at 374Water. "With the DoD citing PFAS investigation and cleanup costs of $1.1 billion through 2020 and plans to obligate an additional $2.1 billion after 2022, technologies like AirSCWO will enable the DoD to continue to operate without harming service personnel or the environment."

Destruction of PFAS could also provide government agencies with significant cost savings when compared with shipping and storage costs once removed from impacted soils and groundwater. By destroying PFAS at military bases, AirSCWO will also remove the threat these substances pose to personnel, their families and surrounding communities.

In the future, the company hopes to increase the type of clientele it works with. This means selling its equipment to local governments, utility companies and waste providers.