Arq, Inc.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. On August 24, 2026, the Board of Directors (the “Board”) of Arq, Inc. (the “Company”) appointed Peter Owino, 52, as the Company’s Chief Accounting Officer, effective September 1, 2026. Mr. Owino previously served as a consultant to the Company where he acted as its Interim Chief Accounting Officer. Mr. Owino will continue to serve as the Company’s principal accounting officer. Mr. Owino has over twenty years of experience in accounting, finance, and Sarbanes-Oxley (SOX) compliance, in both private and public company settings. Prior to his appointment as the Company's Chief Accounting Officer, Mr. Owino was an accounting and finance consultant for Princeton Business Consulting, LLC ("Princeton Business Consulting"), a consulting firm focused on small to mid-sized businesses. Mr. Owino has served in various finance and accounting leadership roles, including as the Corporate Controller of Colliers Engineering & Design, a multidisciplinary engineering firm, from 2024 to 2026, and as the Chief Accounting Officer of Merchant e-Solutions, a merchant acquiring company and global payment processor from 2020 to 2022, where he successfully helped prepare the company for sale to a New York based private equity firm. From 2015 to 2020, Mr. Owino worked as a Director for KPMG New York, providing accounting advisory services. Before that, Mr. Owino was a Senior Director at Finjan Holdings, Inc. and also spent years working as a manager at both Deloitte & Touche and Ernst & Young. Mr. Owino holds a Bachelor of Commerce degree in accounting from Kenyatta University in Nairobi, Kenya. Mr. Owino is also a licensed certified public accountant. On August 25, 2026, Mr. Owino and the Company entered into an employment agreement (the “Agreement”). Pursuant to the terms of the Agreement, Mr. Owino will receive an annual base salary of $350,000 and be eligible to participate in both the Company’s short-term incentive plan with a target bonus opportunity of 55% of his base salary and the Company's long-term incentive plan with a target award of 75% of his base salary. In addition, Mr. Owino received 100,000 restricted stock awards (the “Inducement Awards”) as an inducement to join the Company as an employee, which Inducement Awards were granted outside of the Company’s 2026 Omnibus Incentive Plan. The Inducement Awards will vest in equal installments on each of the first three anniversaries of Mr. Owino’s start date, conditioned upon continued service with the Company. In the event Mr. Owino is terminated without Cause or resigns for Good Reason (each as defined in the Agreement), the Agreement provides for the following severance benefits, subject to his execution and non-revocation of a release of claims: (a) 12 months of continued base salary payments; (b) payment of any short-term incentive or other cash bonus for the year in which such termination occurs based on actual performance; (c) accelerated vesting of all time-based equity awards; (d) accelerated vesting of all performance share units based on actual performance through the termination date; and (e) a lump-sum payment equal to 12 months of COBRA premiums. The Employment Agreement also includes standard non-compete, non-solicitation, confidentiality, inventions assignment, and incentive compensation clawback provisions. The foregoing summary of the Agreement does not purport to be a complete description of the Agreement and is qualified in its entirety by reference to the full text of the Agreement, a copy of which is attached hereto as Exhibit 10.1 and incorporated herein by reference. Mr. Owino’s appointment is not pursuant to any arrangement or understanding with respect to any other person. There are no family relationships between Mr. Owino and any director, executive officer or other person that would require disclosure under Item 401(d) of Regulation S-K. Mr. Owino previously provided consulting services to the Company and acted as its Interim Chief Accounting Officer pursuant to a consulting agreement by and between the Company and Princeton Business Consulting, dated June 15, 2026 (the “Consulting Agreement”). Pursuant to the terms of the Consulting Agreement, the Company paid Princeton Business Consulting an hourly fee of $350, subject to a monthly cap of $63,000, in exchange for Mr. Owino's services as Interim Chief Accounting Officer. During the term of the Consulting Agreement, the Company paid Princeton Business Consulting approximately $200,000. The Consulting Agreement terminated upon Mr. Owino’s appointment as the Company’s Chief Accounting Officer. Otherwise, there are no transactions in which Mr. Owino has an interest requiring disclosure under Item 404(a) of Regulation S-K.

Item 8.01 Other Events. On August 28, 2026, the Company issued a press release announcing the appointment of Mr. Owino and grant of Inducement Awards described in this Current Report on Form 8-K, the full text of which is filed herewith as Exhibit 99.1 and incorporated herein by reference.