Amendment: SEC Form SCHEDULE 13D/A filed by 374Water Inc.

Item 4 of the Schedule 13D is hereby amended and supplemented as follows: Letter Agreement On December 14, 2025, Mr. Nagar entered into a letter agreement with the Issuer (the "Agreement"). Pursuant to the Agreement, Ms. Deanna Rene Estes will tender her resignation as a member of the Board of Directors of the Issuer (the "Board"), which resignation shall be effective following and no later than the date that the inspector of elections for the 2025 Special Meeting of Stockholders of the Issuer held on December 15, 2025 (the "Special Meeting") certifies that the Issuer's stockholders approved and adopted by the requisite vote the Reverse Stock Split Proposal as defined in the Issuer's definitive proxy statement on Schedule 14A filed with the SEC on November 3, 2025. Further, pursuant to the Agreement, the Issuer agreed, among other things, to identify three candidates to be appointed to the Board (the "Candidates"), each of whom shall be mutually acceptable to the Issuer and Mr. Nagar, among other qualifications. Upon the identification of certain Candidates as provided in the Agreement, each of Messrs. Buddie Joe (BJ) Penn and James Vanderhider have agreed to resign as members of the Board. The Issuer also agreed that if the Reverse Stock Split Proposal is approved and adopted by the requisite vote of the Issuer's stockholders at the Special Meeting, the reverse stock split contemplated by the Reverse Stock Split Proposal will be effected at a ratio of 1-for-10 shares. In addition, pursuant to the Agreement, Mr. Nagar has agreed to abide by certain voting commitments. Specifically, Mr. Nagar has agreed to, or his representatives will, appear in person or by proxy at the Special Meeting and to vote all shares of common stock of the Issuer beneficially owned in accordance with the Board's recommendations with respect to all proposals submitted to stockholders at the Special Meeting. The Agreement will remain effective until the earlier of (i) the appointment of the third Candidate contemplated in the Agreement and (ii) the date that is 30 calendar days following written notice of a breach of the Agreement from the non-breaching party, subject to certain conditions as described in the Agreement. The Reporting Persons endeavor to work with the remaining members of the Issuer's Board to identify qualified candidates to fill the existing Board vacancies. The foregoing description of the Agreement is qualified in its entirety by reference to the full text of the Agreement, which is filed as Exhibit 2 to this Amendment No. 1 and is incorporated herein by reference. The Reporting Persons do not have any current plan or proposal that relates to or would result in any of the matters described in Items 4(a) - (j) of Schedule 13D, except as described in this Schedule 13D or as would occur upon, in connection with completion of, or following, any of the actions described in this Schedule 13D.

The information contained in rows 11 and 13 of the cover pages of this Schedule 13D (including the accompanying comments thereto) is incorporated herein by reference. Each Reporting Person expressly disclaims beneficial ownership in the securities reported herein except to the extent such Reporting Person actually exercises voting or dispositive power with respect to such securities.

The information contained in rows 7 through 10 of the cover pages of this Schedule 13D (including the accompanying comments thereto) is incorporated herein by reference.

Except as set forth below, there have been no transactions in the Shares by the Reporting Persons during the past 60 days. During the past 60 days, Mr. Nagar sold Shares in open market transactions: Transaction Date Number of Shares Price per Share ($) 10/17/2025 131,680 0.423(1) 10/20/2025 13,330 0.4208(2) 10/21/2025 284,394 0.4204(3) 10/22/2025 32,791 0.4209(4) 10/22/2025 61,000 0.421(5) 10/23/2025 473,211 0.434(6) (1) The price is a weighted average price. The shares were sold in multiple transactions at prices ranging from $0.4200 to $0.4383. (2) The price is a weighted average price. The shares were sold in multiple transactions at prices ranging from $0.4202 to $0.4211. (3) The price is a weighted average price. The shares were sold in multiple transactions at prices ranging from $0.420 to $0.4208. (4) The price is a weighted average price. The shares were sold in multiple transactions at prices ranging from $0.4207 to $0.4210. (5) The price is a weighted average price. The shares were sold in multiple transactions at prices ranging from $0.4208 to $0.4211. (6) The price is a weighted average price. The shares were sold in multiple transactions at prices ranging from $0.420 to $0.5229.

Not applicable.

Not applicable.

Item 6 of the Schedule 13D is hereby amended and supplemented as follows: The information in Item 4 of this Amendment No. 1 is hereby incorporated by reference. Except as otherwise described in this Schedule 13D, (i) there are no contracts, arrangements, understandings, or relationships (legal or otherwise) among the persons named in Item 2 and between such persons and any person with respect to any securities of the Issuer, including but not limited to transfer or voting of any of the securities, finder's fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or loss, or the giving or withholding of proxies and, (ii) other than standard default and similar provisions contained in loan agreements, none of the securities of the Issuer beneficially owned by any Reporting Person are pledged or otherwise subject to a contingency the occurrence of which would give another person voting or investment power over such securities.

Item 7 of the Schedule 13D is hereby amended and supplemented as follows: Exhibit 2 - Letter Agreement, dated as of December 14, 2025, by and between 374Water Inc. and Yaacov (Kobe) Nagar (incorporated by reference to Exhibit 10.1 to the Issuer's Current Report on Form 8-K filed with the SEC on December 15, 2025).