Star Metro - 374Water to Present New Supercritical Water Oxidation Destruction Data at WEFTEC 2026

MORRISVILLE, NC / ACCESS Newswire / September 22, 2026 / 374Water Inc. (NASDAQ:SCWO) ("374Water" or the "Company"), a leading cleantech and environmental services company developing supercritical water oxidation technology for the permanent destruction of organic waste streams, today announced that it will present new destruction-efficiency data for its AirSCWO technology at WEFTEC 2026, the Water Environment Federation's annual technical exhibition and conference, in New Orleans. In addition to the presentation, the Company will be at booth #2254 with several Executives and team members in attendance.

The 30-minute podium presentation, "Application of Supercritical Water Oxidation for Treating Wastes Contaminated with PFAS, 6PPD-Q, and Other Emerging Pollutants," will be delivered by David Garb, 374Water's Technical Solutions Manager, as part of the session "Fighting PFAS With Fire: Advanced Thermal Conversion for Biosolids Management." [Full abstract below.]

Presentation Details

• Title: Application of Supercritical Water Oxidation for Treating Wastes Contaminated with PFAS, 6PPD-Q, and Other Emerging Pollutants
• Session: Fighting PFAS With Fire: Advanced Thermal Conversion for Biosolids Management
• Date & Time: Wednesday, September 30, 2026, 2:30 - 3:00 p.m. CT
• Location: New Orleans Convention Center, New Orleans, LA
• 374Water Presenter: David Garb, Technical Solutions Manager
• Co-authors: Sudhakar "Sunny" Viswanathan, Vice President of Solutions, 374Water; David Garb Technical Solutions Manager, 374Water; Naomi Senehi, Regional Sales Manager, Aerzen USA

Broad-Spectrum Destruction Across Waste Types

The presentation draws on commercial-, bench-, and laboratory-scale studies to show how a single AirSCWO platform can treat a broad spectrum of contaminants of emerging concern ("CECs") with only moderate adjustments to operating conditions - and clarifies why supercritical water oxidation ("SCWO") is fundamentally distinct from incineration and other thermal methods in its reaction environment, emissions profile, effluent quality, and monitoring requirements. Highlights include:

• PFAS in biosolids: greater than 99.4% destruction and removal efficiency ("DRE") for every PFAS compound detected in a commercial-scale demonstration.
• 6PPD-Q: reduction of the tire-derived contaminant from an inlet concentration of 18 µg/L to non-detect - a DRE greater than 99.99%.
• Mixed pharmaceutical waste: greater than 99% reduction of chemical oxygen demand ("COD") across variable feedstock blends, producing an effluent compliant with the existing industrial site.

A primer on 6PPD-Q:

6PPD-Q forms when tires degrade and chemicals react with ozone in the air. The particles wash off roads into waterways through stormwater runoff. It's extraordinarily toxic in small quantities. It is acutely lethal to salmon and was confirmed as the cause of large scale die-offs in the Pacific Northwest. Human exposure is confirmed, having been found in urine, blood, and cerebrospinal fluid, with possible neurotoxic signals and widespread fatality identified in animal studies. Regulatory momentum is building, with EPA investigating it under the Toxic Substances Control Act ("TSCA").

6PPD-Q is in the runoff from driveways and roads, it enters our drinking water systems from rivers, groundwater, and reservoirs, and current water infrastructure does not manage for it. We destroy it.

Building on Federal Destruction Results

The WEFTEC data extends a series of milestones for 374Water's PFAS destruction program. Earlier in 2026, the Company publicly released results from a U.S. Department of Defense project led by the Defense Innovation Unit ("DIU") and the Environmental Security Technology Certification Program ("ESTCP"), in which AirSCWO destroyed more than 99.9% of PFAS in aqueous film-forming foam ("AFFF"). The project's success memo supports a federal procurement pathway for PFAS destruction, which 374Water is pursuing together with Arcadis under a partnership framework for federal deployment of AirSCWO. These federal opportunities include sludge and biosolids in remote locations, along with other emerging contaminants more generally.

"Demand for permanent destruction is accelerating across every market we serve," said Sunny Viswanathan, Vice President of Solutions at 374Water. "Municipalities, federal agencies, and industrial generators are no longer asking whether supercritical water oxidation works - they are asking how quickly we can put it to work on their waste streams. What makes AirSCWO compelling is that one platform can destroy PFAS, 6PPD-q, pharmaceuticals, and other emerging contaminants without simply transferring the problem elsewhere. WEFTEC is where we put the data behind that versatility in front of the people who need it."

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

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Forward-looking statements include, without limitation, statements regarding 374Water's technology and its destruction and removal efficiencies, its participation in and the anticipated content of its WEFTEC 2026 presentation, demand for its solutions across municipal, federal, and industrial markets, its federal market opportunities and procurement pathway, and its partnership with Arcadis. These statements are based on management's current expectations and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied. Factors that could cause such differences include, but are not limited to, the Company's ability to commercialize and scale its technology, the timing and outcome of federal procurement processes, the performance of its partnerships, market adoption, and other risks described in the Company's filings with the U.S. Securities and Exchange Commission, including its Annual Report on Form 10-K and subsequent reports. 374Water undertakes no obligation to update any forward-looking statements except as required by law.

Investor Relations Contact

Belton Copp
Vice President
Direct: 401-419-1545
[email protected]
www.374Water.com

PRESENTATION ABSTRACT

Application of Supercritical Water Oxidation for Treating Wastes Contaminated with PFAS, 6PPD-Q, and Other Emerging Pollutants

The rapid emergence of contaminants of emerging concern (CECs) in municipal and industrial waste streams has accelerated the need for treatment technologies capable of achieving verifiable destruction across a broad chemical spectrum. Supercritical Water Oxidation (SCWO) has increasingly been positioned within the landscape of "thermal technologies," yet is often compared-sometimes inappropriately-to systems that differ fundamentally in chemistry, operating mechanisms, monitoring requirements, and achievable performance. Current technology comparison studies typically fall into two categories: (1) comparisons to broad-treatment thermal technologies capable of addressing many or most CEC classes, and (2) comparisons to highly specialized technologies designed to target only one or a small subset of contaminants. In both cases, economic or performance comparisons often lack the foundational data needed to be meaningful.

For technologies in the first bucket, comparisons are limited because regulatory monitoring and verification requirements differ widely across platforms. Many systems do not require, or are not capable of, collecting mass balance data that confirms true destruction rather than transformation or transfer of contaminants. As a result, economic comparisons fail to reflect the cost of achieving verified destruction. For the second bucket-specialized solutions developed in response to accelerated PFAS regulatory pressure-economic analyses are typically framed around PFAS alone. This narrow focus does not account for the longer-term value of a technology capable of treating diverse CECs such as pharmaceuticals, tire-derived contaminants (e.g., 6PPD-q), industrial organics, and complex waste matrices. Consequently, technology selection is often made without considering the operational and financial advantages of broad applicability.

This presentation addresses the gap created by these incomplete comparisons by providing new data that illustrates how SCWO performance varies across waste types and CEC classes with only moderate adjustments to system operating parameters. Because SCWO is frequently and incorrectly grouped with incineration and other thermal destruction methods, this work clarifies the fundamental distinctions in reaction environment, destruction mechanisms, emissions profiles, effluent quality, and monitoring requirements. A detailed overview of SCWO's flexibility is presented through data generated from municipal sludges, controlled laboratory studies using spiked CEC solutions, and blended industrial waste streams.

Methods: A series of waste matrices were evaluated to assess the performance of SCWO on eliminating various CECs. The contaminants tested include PFAS compounds in wastewater sludge, analytical grade 6PPD-q, and a pharmaceutical waste blend containing various solvents and organic contaminants. Variables examined include alkaline addition, reactor temperature, operating pressure, mixing intensity, and influent water content. Performance was measured using process indicators-pressure drop behavior, temperature stability, CO emissions, metals content in the liquid effluent-and by assessing physical characteristics of the resulting effluent streams. Analytical measurements of contaminant concentrations in the SCWO influent and effluent were used to determine destruction efficiency.

Results:

PFAS in Sludge: Multiple datasets were generated by treating sludges with various concentrations of PFAS (variations on both a diurnal and seasonal level) via SCWO to determine a range of typical PFAS destruction and removal efficiencies (Figure 1). This commercial scale demonstration which showed >98% DRE for every PFAS compound detected in the influent verified the effective treatment of PFAS in biosolids using SCWO. Additionally, valuable insights on run-time and reliability were realized and allowed for optimization of the unit both mechanically and operationally.

6PPD-q: This project was conducted using a bench-scale SCWO system. The main benefits from first conducting this research at bench scale were (1) resource efficiency and (2) cost-effective identification of conditions to be scaled up to commercial SCWO systems. Analytical results showed a reduction from an inlet 6PPD-q concentration of 18 ug/L to non-detect in both of the two effluent grab samples. Considering the method detection limits of 0.64 and 0.58 ng/L (0.00064 and 0.00058 ug/L), a DRE of >99.99% was achieved.

Mixed Pharmaceutical Waste: Two variables were tested - the feedstock blend and the SCWO operating temperature and pressure - to determine how versatile the SCWO system is in treating the waste should the blend vary from batch to batch. The results, using COD as a surrogate for all organic constituents, illustrated that the impact of waste blend and/or SCWO operating conditions was marginal. In all instances, >99% removal of COD was achieved, resulting in a SCWO effluent that was in compliance with the existing industrial site.

Significance: The ability of SCWO technology to treat a wide range of contaminants with minimal operating adjustments suggests that the benefits of investing in the technology may outweigh the higher OPEX of SCWO as compared to traditional waste disposal techniques such as landfilling.

Authors: Naomi Senehi, Regional Sales Manager, Aerzen USA; David Garb, Technical Solutions Manager - Industrial Applications & Emerging Contaminants, 374Water Inc.; Sudhakar Viswanathan, VP, Solutions, 374Water Inc.

Speaker: David Garb

Session: Fighting PFAS With Fire: Advanced Thermal Conversion for Biosolids Management

When: Wednesday, September 30, 2026, 2:30 PM to 3:00 PM - New Orleans Convention Center

Moderated by: Stephanie Spalding, HDR; Julia Ann Funk, Jacobs Engineering

SOURCE: 374Water Inc.

View the original press release on ACCESS Newswire

Y.X. Gagnon--SMC