374Water Completes Commercial-Scale Field Demonstration for DoD ESTCP/DIU Project

Executed PFAS Destruction of Multiple Concentrated Waste Streams at Commercial TSDF using AirSCWO™ 6 System

Final Report to be Released by Q1 2026

DURHAM, N.C., Oct. 21, 2025 (GLOBE NEWSWIRE) -- 374Water Inc. (NASDAQ:SCWO) ("374Water" or the "Company"), a global leader in organic waste destruction technology and services for the industrial, municipal, and federal markets, today announced the successful completion of a commercial-scale field demonstration at Clean Earth's Detroit, MI facility as part of a previously announced Department of Defense ("DoD") project.

In February 2025, 374Water announced its participation in a highly anticipated DoD project, led by the Defense Innovation Unit ("DIU") in collaboration with DoD Environmental Security Technology Certification Program ("ESTCP"), to evaluate commercial-scale technology solutions to destroy per- and polyfluoroalkyl ("PFAS") contaminated wastes. Generally, the DIU focuses on accelerating the adoption of commercial technology to solve operational challenges at speed and scale, and this project was designed to demonstrate and promote the application of technologies that can fully and cost-effectively destroy PFAS-containing wastes.

For six weeks from July through September 2025, 374Water processed a total of six representative concentrated PFAS-impacted wastes at a Clean Earth Treatment Storage and Disposal Facility ("TSDF") located in Detroit, MI in a series of one day trials using its AirSCWO™ 6 System. In total, approximately 900 gallons of PFAS-laden feedstocks were treated over 80 hours of runtime. Concentrated wastes processed included Surface Active Foam Fractionation ("SAFF") foamate, a Cyclodextrin-based media regenerant distillate solution, an ion exchange regenerant still bottoms solution, Aqueous Film-Forming Foam ("AFFF"), spent granular activated carbon ("GAC"), and spent ion exchange resin ("IX"). One batch of mixed liquids, consisting of AFFF, foamate, and Cyclodextrin regenerant distillate was also processed. Following the treatment of these PFAS-impacted concentrated wastes, a comprehensive and robust analysis of both PFAS and non-PFAS parameters generated via sampling of the stack gas emissions and liquid effluent is underway. Assessment of performance objectives, including destruction removal efficiencies ("DREs"), fluorine mass balance, and cost model is currently being prepared by Arcadis, the project's prime engineering contractor. These results are expected to be publicly released by Q1 2026.

"This deployment again successfully demonstrated the effectiveness, scalability and versatility of our AirSCWO™ technology," said Stephen Jones, Interim President and Chief Executive Officer of 374Water. "The project served to further validate our technology for a range of most common PFAS-containing wastes, providing comprehensive emissions and liquid sampling and operational and economic data to support a centralized ‘hub' deployment model for the DoD. In fact, we were able to complete the demonstration of the planned six waste streams ahead of schedule, providing the opportunity to add a mixed waste stream for processing. We would like to thank our partners Arcadis and Clean Earth and everyone at the DoD, ESTCP and DIU who made this demonstration possible.

"This project represented a major step forward in our effort to provide the DoD with commercial PFAS treatment options for a variety of scenarios and waste types. This DoD initiative combines methods for concentrating and destroying PFAS, both on- and off-site, highlighting the growing demand for reliable and modular PFAS destruction technologies across federal, state and municipal government agencies. We are highly focused on bringing our Waste Destruction Services ("WDS") – a modular solution to eliminate PFAS, hazardous, and non-hazardous wastes – to market," concluded Jones.

About 374Water

374Water Inc. (NASDAQ:SCWO) is a global industrial technology and services company providing innovative solutions addressing wastewater treatment and waste management issues within the industrial, municipal, and federal markets. 374Water's AirSCWO™ technology is designed to efficiently destroy and mineralize a broad spectrum of non-hazardous and hazardous organic wastes, producing safe dischargeable water streams, safe mineral effluent, safe vent gas, and recoverable heat energy. 374Water's AirSCWO™ technology has the potential to assist its customers to meet discharge requirements, reduce or eliminate disposal costs, remove bottlenecks, and reduce litigation and other risks. 374Water continues to be a leader in innovative waste treatment solutions, dedicated to creating a greener future and eradicating harmful pollutants. Learn more by visiting www.374water.com and follow us on LinkedIn.

Cautionary Language on Forward-Looking Statements

Certain statements in this communication are "forward-looking statements" within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995, as amended. These statements relate to future events or our future financial performance, including statements relating to whether 374Water will be able to unlock revenue from its WDS operations, whether 374Water will be successful in obtaining federal, municipal and industrial waste destruction contracts, the timing for 374Water to launch WDS operations and 374Water's ability to establish additional WDS operations, 374Water's ability to scale its operations, demand for 374Water's solutions, and 374Water's ability to destroy PFAS at scale, and 374Water's future prospects and involve known and unknown risks, uncertainties, and other factors that may cause 374Water's actual results, levels of activity, performance, or 374Water's achievements or those of its industry to be materially different from those expressed or implied by any forward-looking statements. In some cases, forward-looking statements may be identified by the use of words like "may," "will," "could," "would," "should," "expect," "plan," "anticipate," "intend," "believe," "estimate," "project," "consider," "predict," "potential," "feel," or other comparable terminology. 374Water has based these forward-looking statements on its current expectations, assumptions, estimates, beliefs, and projections. While 374Water believes these expectations, assumptions, estimates, and projections are reasonable, such forward-looking statements are only predictions and involve known and unknown risks and uncertainties, many of which involve factors or circumstances that are beyond the 374Water's control. These and other important factors, including those discussed under "Risk Factors" in 374Water's Form 10-Q for the quarter ended June 30, 2025, as well as 374Water's subsequent filings with the SEC, may cause actual results, performance, or achievements to differ materially from those expressed or implied by these forward-looking statements. The forward-looking statements herein are made only as of the date they were first issued, and unless otherwise required by applicable securities laws, 374Water disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise.

Investor Relations and Media Contact

Chris Tyson

Executive Vice President

MZ North America

Direct: 949-491-8235

[email protected]

www.mzgroup.us