374Water's Mobile AirSCWO System Completes Phase 1 in St. Cloud, MN with Phase 2 Underway with Strong Early Results

The mobile AirSCWO brings the full capability of larger modular systems for wastes that cannot be transported and for onsite pilot demonstrations

MORRISVILLE, NC / ACCESS Newswire / June 30, 2026 / 374Water Inc. (NASDAQ:SCWO) ("374Water" or the "Company"), a leading cleantech and environmental services company deploying supercritical water oxidation technology for the permanent destruction of organic waste through its proprietary AirSCWO™, today announced the completion of Phase 1 of the St. Cloud, Minnesota campaign and provided an update on operations of its mobile AirSCWO system.

Project Update

The St. Cloud deployment is being conducted under a $600,000 Waste Destruction Services contract with the City of St. Cloud, in partnership with Barr Engineering, at the City's Nutrient, Energy, and Water Recovery Facility. This facility is a national leader, known for its innovative resource recovery practices. Receiving approximately 10 million gallons daily, the facility exemplifies a culture of innovation as it consistently pioneers and pilots industry-changing technologies.

The pilot program is scheduled to run through mid-September 2026, processing undigested and post-thermal hydrolysis digested waste streams as part of the State of Minnesota's LCCMR-supported evaluation of AirSCWO technology for the destruction of PFAS-laden wastes.

374Water's mobile AirSCWO system departed the Company's Orlando testing facility in May.

Phase 1 Complete: Class B Biosolids Processing

The mobile AirSCWO system has successfully completed Phase 1 of the St. Cloud deployment, a four-week processing campaign targeting Class B biosolids at solids concentrations of up to 10%. The Company is conducting analyses of Phase 1 performance data and is seeing positive early results consistent with previous AirSCWO campaigns, providing yet another proof point of technology validation.

The mobile system allows for minimal infrastructure in places where that is not viable.

Phase 2 Underway: Class A Lystek Biosolids

Building on the completion of Phase 1, the 374Water field team is now one week into Phase 2 of the deployment, which involves processing Class A Lystek biosolids. Operations have been steady, with no major operational challenges encountered to date. The Company is pleased with the pace of the program and the performance of the mobile system under field conditions.

The campaign has now seen multiple types of biosolids successfully processed with more to come as the project moves forward.

A successful pilot is expected to support 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. We are seeing eager demand for this system and are excited to announce the successive campaign following successful performance in Minnesota.

Expanding the Mobile AirSCWO Commercial Pipeline

Beyond the LCCMR project, 374Water's solutions team is actively developing additional projects that will follow this deployment and are designed to demonstrate the full commercial capabilities of AirSCWO in a mobile configuration. The Company is encouraged by the interest it is seeing across multiple end markets and believes the St. Cloud deployment is building a foundation for a scalable, recurring mobile services business.

"We are proud of our field team and the steady, professional operations they have delivered since day one in St. Cloud," said Brad Meyers, Chief Operating Officer of 374Water. "Phase 1 is complete with strong early data, and Phase 2 is off to an equally solid start. What we're seeing in the field validates both the reliability of the technology and the commercial model. Importantly, this deployment is reinforcing what we're already hearing from the market - demand for mobile AirSCWO services is real and growing, both as a complement to our expanding fixed-site WDS business and as a demonstration platform that is opening doors with new customers."

374Water will continue to provide updates on the St. Cloud pilot program, Phase 2 performance results, and the development of follow-on mobile deployments as they become available.

About 374Water

374Water Inc. (NASDAQ:SCWO) is a cleantech environmental 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 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

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. Words such as "anticipate," "believe," "confidence," "could," "design," "estimate," "expect," "intend," "may," "plan," "predict," "project," "potential," or other comparable terminology are intended to identify forward-looking statements, including, without limitation, 374Water's expectations regarding Phase 2 performance, the development of follow-on mobile deployments, the potential for multiple millions of dollars in revenue from Minnesota operations, and its estimate that a single mobile AirSCWO system has the potential to generate between $500,000 and $1.5 million in annual revenue depending on deployment cadence, waste stream composition, and contract structure. 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 374Water's control. These forward-looking statements are subject to risks and uncertainties, including those discussed under "Risk Factors" in 374Water's Form 10-K for the year ended December 31, 2025, and in 374Water's subsequent filings and reports with the SEC. The forward-looking statements herein are made only as of the date they were first issued, and unless otherwise required by 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 Contact

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

SOURCE: 374Water Inc.