TETRA TECHNOLOGIES, INC. ANNOUNCES RESOURCE UPGRADE FOR ARKANSAS BROMINE PROJECT AND ADDITIONAL CRITICAL MINERALS

Investor Day Scheduled for September 25 at the New York Stock Exchange

THE WOODLANDS, Texas, Sept. 23, 2025 /PRNewswire/ — TETRA Technologies, Inc. (“TETRA” or the “Company”) (NYSE:TTI) announced today an updated resources report prepared in accordance with Regulation S-K 1300: Definitive Feasibility Study (“DFS”). RESPEC loop Company, LLC (“RESPEC”) prepared the Technical Report Summary dated September 22, 2025 (the “Resource Report”) as an update to its August 2024 resources and reserves report and incorporates the results of the DFS, including bromine reserve determinations, as of August 1, 2025.

Brady Murphy, TETRA’s president and CEO said, “Following the completion of our final exploration well in our Evergreen Unit, the processing of additional seismic data and the publishing of Smackover Lithium’s SWA Phase 1 Definitive Feasibility Study, we are very encouraged by our updated DFS report. The updated DFS report reflects very positive results, advancing the classification of bromine and lithium resources and increasing the totals in the Measured and Indicated Mineral Resources categories. In addition, the report identifies the presence of significant volumes of magnesium and manganese – which together with lithium have been classified as critical minerals by the US government.”

            Highlights from the updated Resource Report include:

• TETRA’s expanded Evergreen Unit Bromine Resources (Measured and Indicated) increased by 173% and total 431 ktons from the previously reported 158 ktons. Proven and probable bromine reserves remain consistent with the prior report of 744 ktons. TETRA holds 65% working interest in the expanded Evergreen Brine unit as further detailed below.
• Measured and Indicated Bromine Resources increased from 158 ktons to 3.57 million tons across all TETRA acreage.
• TETRA’s expanded Evergreen Unit lithium resources (Measured and Indicated) increased by 163% to 585 ktons of lithium carbonate equivalent (LCE) from the previously reported 222 ktons.

The identification of

• Magnesium resources (Measured and Indicated) of 2.18 million tons across all TETRA brine lease acreage, which had not been included in previous reports. An additional 1.88 million tons of Magnesium Inferred Resources are reported.
• Manganese Resources (Measured and Indicated) of 47,000 tons across all TETRA brine lease acreage, which had not been included in previous reports.
  
  *See cautionary note concerning estimates of Mineral Resources and Reserves.

Brady Murphy further stated, “This is another very positive step for our plans for the future development of our Arkansas resources. Based on our plans for our bromine plant and production, this update further validates the volumes of bromine resources that are expected to be available to support our investments and growth initiatives. The upgraded lithium resources in our Evergreen Unit, as well as the positive announcement from Smackover Lithium (discussed below), are also very encouraging. The identification of concentrations of magnesium and manganese, which the U.S. government designated as critical minerals, in these same resources, is also a very important development as we explore technology and partnerships to extract these critical minerals.” 

In addition, Smackover Lithium, a joint venture between Standard Lithium Ltd. (“Standard Lithium” (TSXV: SLI) (NYSE.A: SLI)) and Equinor (NYSE: EQNR), on September 3, 2025, reported a total of 780 ktons of proven and probable LCE reserves and an additional 515 ktons of Measured and Indicated Resources on approximately 35,000 acres where TETRA is the brine lease holder. Smackover Lithium acquired rights to lithium pursuant to an Option Agreement, and in exchange, TETRA will receive a 2.5% royalty on any gross proceeds that may be realized from the lithium recovered from these holdings. All other minerals, including bromine, within the 35,000 Option Agreement acreage are owned by TETRA.

TETRA currently owns mineral rights to approximately 40,000 acres of brine leases in Southwest Arkansas, which contain bromine, lithium, magnesium, manganese, and other key minerals. Although bromine is the initial target for TETRA’s commercial project as outlined in the DFS report, lithium, magnesium, and manganese have been designated as critical minerals by the U.S. government and will be present in TETRA’s future brine production along with the bromine.

The various acres and units where TETRA holds brine interests and mineral rights are summarized below.

• Evergreen Brine Unit: The expanded Evergreen Brine Unit includes approximately 6,953 gross acres of brine interests. All minerals produced from brine in this unit are owned 65% by TETRA and 35% by Saltwerx LLC, a subsidiary of Exxon Mobil. The Evergreen Brine Unit consists of the initial Evergreen Brine Unit approved by the AOGC in October 2023 together with an adjacent Evergreen Expansion Brine Unit approved by the AOGC in early 2025.
• Reynolds Brine Unit: In addition, the 20,854 gross acres in the Reynolds Brine Unit are primarily held under TETRA brine leases as approved by the AOGC in early 2025. Although TETRA owns all the brine leases within the Reynolds Brine Unit, the operator of the Reynolds Brine Unit is SWA Lithium LLC, which is the joint venture between Standard Lithium Ltd and Equinor. SWA Lithium (now Smackover Lithium) acquired rights to lithium in the 20,854-acre Reynolds Unit from TETRA pursuant to the Option Agreement. In exchange, TETRA will receive a 2.5% royalty on the gross proceeds from the sale of lithium products. All other minerals, including bromine, within the Reynolds Brine Unit are owned by TETRA.
• Non-Unitized Acreage: In addition, TETRA also holds mineral rights in 10,951 net acres of remaining brine leases in Southwest Arkansas that are not part of either the Evergreen Unit or Reynolds Brine Unit. These additional 10,951 net acres of brine leases are not yet unitized. Of those, 9,114 of these non-unitized net acres are part of the Option Agreement pursuant to which Smackover Lithium holds the lithium rights. Pursuant to the Option agreement, TETRA will receive a 2.5% royalty on lithium proceeds, and TETRA retains ownership of all other minerals. For the remaining 1,837 non-unitized net acres, TETRA holds all mineral rights including lithium.

See cautionary note concerning estimates of Mineral Resources and Reserves as well as the full S-K 1300 Report dated September 22, 2025, available on our website under the Investors section at the Presentations link at www.onetetra.com.

Investor Day Registration
TETRA’s executive team will be hosting an Investor Day on Thursday, September 25, 2025, at 8:30AM EST, at The New York Stock Exchange (“NYSE”). Click here to Register to listen via web cast. The investor presentation will be available on our website in the morning of September 25. Please visit the Investors section at www.onetetra.com to view it.

Company Overview
TETRA Technologies, Inc. is an energy services and solutions company focused on developing environmentally conscious services and solutions that help make people’s lives better. With operations on six continents, the Company’s portfolio consists of Energy Services, Industrial Chemicals, and Critical Minerals. In addition to providing products and services to the oil and gas industry and calcium chloride for diverse applications, TETRA is expanding into the low-carbon energy market with chemistry expertise, key mineral acreage, and global infrastructure, helping to meet the demand for sustainable energy in the twenty-first century. Visit the Company’s website at www.onetetra.com for more information or connect with us on LinkedIn.

Cautionary Statements
Qualified Person: All scientific and technical information related to the 2025 S-K 1300 Technical Report Summary has been prepared by, or under the supervision of RESPEC Company LLC, the firm serving as the “Qualified Person” as defined by Item 1300 of Regulation S-K (“SK 1300”) under the Securities Exchange Act of 1934, as amended.

Cautionary Note Concerning Estimates of Proven and Probable Mineral Reserves and Measured, Indicated and Inferred Resources: The estimates of mineral reserves shown in this press release have been prepared in accordance with SK-1300. The estimation of measured resources and indicated resources involve greater uncertainty as to their existence and economic feasibility than the estimation of proven and probable reserves, and therefore investors are cautioned not to assume that all or any part of measured or indicated resources will ever be converted into S-K 1300-compliant reserves. The estimation of inferred resources involves far greater uncertainty as to their existence and economic viability than the estimation of other categories of resources, and therefore it cannot be assumed that all or any part of inferred resources will ever be upgraded to a higher category. Further, it is uncertain if all such measured, indicated and inferred mineral resources will ever be economically developed. Investors are cautioned that mineral resources do not have demonstrated economic value and further exploration may not result in the estimation of a mineral reserve.

In addition, resource and reserve estimation is a process of estimating underground accumulations of minerals that cannot be measured in an exact way. The accuracy of any resource or reserve estimate depends on the quality of available data, the interpretation of such data and price and cost assumptions made by Qualified Persons. The results of drilling, testing and production activities may justify revisions of previous estimates. Accordingly, mineral resource and reserve estimates may differ significantly from the quantities of minerals that are ultimately produced. Further, there are a number of uncertainties related to processing lithium and other minerals other than bromine, which is an inherently difficult process. Therefore, you are cautioned not to assume that all or any part of our resources can be economically or legally commercialized.

Forward Looking Statements – Disclaimer
This press release includes certain statements that are deemed to be forward-looking statements that convey the uncertainty of future events, activities, expectations or outcomes that the Company intends to be included within the safe harbor protections provided by the federal securities laws. These forward-looking statements include statements concerning the completion of new projects and the profitability thereof; measured, indicated and inferred mineral resources estimates and proven and probable reserve estimates, the potential extraction of lithium, bromine and other minerals from our Evergreen Unit and other leased acreage, the economic viability thereof, the demand for such resources, the timing and costs of such activities, and the expected revenues, including any royalties, profits and returns from such activities; the timing and success of our bromine production wells and the construction of our bromine processing facility and related engineering activities; and statements regarding the Company’s beliefs, expectations, plans, goals, future events and performance, and other statements that are not purely historical. These forward-looking statements are based on certain assumptions and analyses made by the Company in light of its experience and its perception of historical trends, current conditions, expected future developments and other factors it believes are appropriate in the circumstances. Such statements are subject to several risks and uncertainties, many of which are beyond the control of the Company.

Investors are cautioned that any forward-looking statements are not guarantees of future performance or results and that actual results or developments may differ materially from those projected in the forward-looking statements. Factors which may cause actual results to differ materially from current expectations include, but are not limited to: changes in general economic conditions; opportunity risks, such as mineral extraction, demand therefor, or realizing industrial and other benefits expected from bromine processing; our ability to develop a bromine processing facility and risks inherent in the construction such facility; the accuracy of our resources report, feasibility study and economic assessment regarding our lithium and bromine acreage; equipment supply, equipment defects and/or our ability to timely obtain equipment components; competition from existing or new competitors; risks associated with changes in laws and regulations, or the imposition of economic or trade sanctions affecting international commercial transactions, including legislative, regulatory and policy changes, such as unexpected changes in tariffs, trade barriers, price and exchange controls; and other the factors described in the section titled “Risk Factors” contained in the Company’s Annual Reports on Form 10-K, as well as other risks identified from time to time in its reports on Form 10-Q and Form 8-K filed with the Securities and Exchange Commission. Investors should not place undue reliance on forward-looking statements. Each forward-looking statement speaks only as of the date of the particular statement, and the Company undertakes no obligation to update or revise any forward-looking statements, except as may be required by law.

SOURCE TETRA Technologies, Inc.