Multi-feedstock campaign advances the State of Minnesota's evaluation of AirSCWO for permanent PFAS destruction

MORRISVILLE, NC / ACCESS Newswire / August 25, 2026 / 374Water Inc. (NASDAQ:SCWO) ("374Water" or the "Company"), a leading cleantech and environmental services company deploying supercritical water oxidation technology for the destruction of PFAS and other organic waste streams, today announced the completion of Phase 3 of its mobile AirSCWO deployment in St. Cloud, Minnesota - concluding a three-phase sequence that successfully treated three distinct biosolids feedstocks - and provided an update on the campaign as the field team begins Phase 4.

The St. Cloud deployment is being conducted under a $600,000 Waste Destruction Services ("WDS") contract with the City of St. Cloud, in partnership with Barr Engineering Co. ("Barr"), at the City's Nutrient, Energy, and Water Recovery Facility ("NEWRF"). The campaign is part of the State of Minnesota's evaluation of AirSCWO technology for the destruction of PFAS-laden wastes, supported by the Legislative-Citizen Commission on Minnesota Resources ("LCCMR") and the State's Environment and Natural Resources Trust Fund ("ENRTF").

Phases 1-3 Complete: Three Distinct Feedstocks Successfully Processed

From June 1 through July 31, the field team successfully completed the first three phases of the campaign, treating three distinct feedstocks - Class B biosolids, Class A biosolids, and pre-digestion sludge - under a range of operating conditions. Phase 3 concluded with no operational issues, and the Company is currently analyzing the performance data.

Operations to date have produced impressive preliminary destruction results and a solid performance dataset across multiple feedstocks and operating conditions, consistent with what the Company has observed in previous campaigns.

"What makes this deployment unique is the emphasis on robust mass and energy balances around our mobile unit, and optimization of the sampling intervals to account for dynamics of the system. Thanks to our partner University of St. Thomas for helping us raise the bar on instrument accuracy, and for their push to detect and quantify the fate of 96 PFAS species, which is more than twice the number of species currently measured via EPA Method 1633," said Raj Melkote, Chief Technology Officer at 374Water.

Phase 4 Begins: Class B Biosolids Blended with Spent GAC

Phase 4 began August 10 and is focused on treating Class B biosolids blended with spent granular activated carbon ("GAC") from a drinking water purification plant in Cottage Grove, MN. GAC is among the most widely used media for capturing PFAS from water, and spent, PFAS-laden GAC is itself a growing disposal challenge.

AirSCWO's ability to effectively process solids is a significant market differentiator, and doing so with blended waste stream expands our value proposition. This ability underscores the breadth of the technology's commercial applicability.

Commercial Potential and Follow-On Opportunity

A successful pilot is expected to support the State of Minnesota's broader assessment of AirSCWO for permanent PFAS destruction - an outcome the Company believes could generate multiple millions of dollars in revenue, including recurring annual revenue from ongoing operations and services. The mobile AirSCWO system is estimated to have the potential to generate between $500,000 and $1.5 million in annual revenue per unit, depending on deployment cadence, waste stream composition, and contract structure.

Beyond the St. Cloud project, 374Water's solutions team continues to develop follow-on mobile deployments designed to demonstrate the full commercial capabilities of AirSCWO in a mobile configuration. The Company is encouraged by the demand it is seeing across multiple end markets and believes the St. Cloud campaign is building a foundation for a scalable, recurring mobile services business.

"Our team has done a fantastic job at integrating our technology into St. Cloud's facility, completing three phases across three very different biosolids feedstocks with no operational issues," said Brad Meyers, Chief Operating Officer of 374Water. "While we finalize our analysis of the data, the performance we've observed to date has been encouraging and in line with what we expect from AirSCWO. This blended waste stream will be another accomplishment for the team, and I am grateful for project partners' support and participation."

374Water will continue to provide updates on the St. Cloud pilot program, campaign performance results, and the development of follow-on mobile deployments as they become available.

About 374Water

374Water Inc. (NASDAQ:SCWO) is a cleantech and environmental services company deploying supercritical water oxidation technology for the destruction of organic waste streams within the industrial, municipal, and federal markets. 374Water's AirSCWO technology is designed to efficiently destroy and mineralize a broad spectrum of nonhazardous 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.

Forward-Looking Statements

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Investor Relations Contact

Belton Copp
Vice President
Direct: 401-419-1545
Belton.Copp@374water.com
www.374Water.com

SOURCE: 374Water Inc.