# EDGAR Filing Document

**Accession Number:** 0000831641
**File Stem:** 0001104659-26-001352
**Filing Date:** 2026-1
**Character Count:** 11758
**Document Hash:** b652dccbdedab0037091052c5b0b0125
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-001352.hdr.sgml**: 20260106

**ACCESSION NUMBER**: 0001104659-26-001352

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 14

**CONFORMED PERIOD OF REPORT**: 20260106

**ITEM INFORMATION**: Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

**ITEM INFORMATION**: Other Events

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260106

**DATE AS OF CHANGE**: 20260106

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** TETRA TECH INC
- **CENTRAL INDEX KEY:** 0000831641
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-ENGINEERING SERVICES [8711]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 954148514
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 0928

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-19655
- **FILM NUMBER:** 26512158

**BUSINESS ADDRESS:**
- **STREET 1:** 3475 EAST FOOTHILL BOULEVARD
- **CITY:** PASADENA
- **STATE:** CA
- **ZIP:** 91107
- **BUSINESS PHONE:** 6263514664

**MAIL ADDRESS:**
- **STREET 1:** 3475 EAST FOOTHILL BOULEVARD
- **CITY:** PASADENA
- **STATE:** CA
- **ZIP:** 91107

?xml version='1.0' encoding='ASCII'?

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**WASHINGTON, D.C. 20549**

**FORM 8-K**

**CURRENT REPORT**

**Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934**

Date of Report (Date of earliest event reported):

**January 6, 2026**

**TETRA TECH, INC.**

(Exact name of registrant as specified in its charter)

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| | | |
|:---|:---|:---|
| **Delaware** | **0-19655** | **95-4148514** |
| (State or other jurisdiction<br> of incorporation) | (Commission<br> File Number) | (IRS Employer<br> Identification Number) |

---

**3475 East Foothill Boulevard** **, Pasadena, California 91107**

(Address of principal executive office, including zip code)

**(626) 351-4664**

(Registrant's telephone number, including area code)

**Not Applicable**

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

◻ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) <br>

◻ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) <br>

◻ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) <br>

◻ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

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| | | |
|:---|:---|:---|
| **Title of each class** | **Trading symbol(s)** | **Name of each exchange on which registered** |
| Common Stock, $0.01 par value | TTEK | The Nasdaq Stock Market LLC |

---

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging Growth Company ◻

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ◻

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| | |
|:---|:---|
| **Item 5.02.** | **Departure of Directors or Principal Officers; Election of Directors; Appointment of Principal Officers.** |

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*Appointment of Officer*

On January 6, 2026, Tetra Tech, Inc. (the "Company") announced that Roger R. Argus, currently President, will succeed Dan L. Batrack as Chief Executive Officer and join the Company's Board of Directors. Mr. Batrack, currently Chairman and Chief Executive Officer, will continue as Executive Chairman of the Board of Directors. The changes are effective February 19, 2026, the date of the Company's annual shareholder meeting. It is expected that Mr. Batrack will serve as Executive Chairman for a minimum of two years.

Mr. Argus joined the Company more than 30 years ago, and has held increasingly responsible positions. He has served as President since October 2025. He previously served as Executive Vice President, Corporate Development from November 2024 to October 2025, and President, Commercial/International Services Group from October 2023 to October 2025. Prior to this, Mr. Argus served as Senior Vice President and President, Government Services Group from October 2018 to October 2024, and President, U.S. Government Division from October 2017 to November 2024. During his tenure with the Company, he also has served as project and program manager and business unit leader.

There are no arrangements or understandings between either Mr. Argus or Mr. Batrack and any other persons pursuant to which each was appointed as an officer or director of the Company (other than arrangements or understandings with directors or officers of the Company acting solely in their capacities as such). There are also no family relationships between either Mr. Argus or Mr. Batrack and any director or executive officer of the Company, and neither Mr. Argus nor Mr. Batrack is party to or has any direct or indirect material interest in any transaction requiring disclosure under Item 404(a) of Regulation S-K.

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| | |
|:---|:---|
| **Item 8.01.** | **Other Events.** |

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On January 6, 2026, the Company issued a press release announcing the matters described in Item 5.02. A copy of the press release is attached as Exhibit 99.1 and is incorporated by reference herein.

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| | |
|:---|:---|
| **Item 9.01.** | **Financial Statements and Exhibits.** |

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| | |
|:---|:---|
| (d) | Exhibits |
| [99.1](tm262000d1_ex99-1.htm) | [Press Release, dated January 6, 2026.](tm262000d1_ex99-1.htm) |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document) |

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**SIGNATURES**

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | |
|:---|:---|:---|
|  | TETRA TECH, INC. | TETRA TECH, INC. |
| Date: January 6, 2026 | By: | /s/ Dan L. Batrack |
|  |  | Dan L. Batrack |
|  |  | Chairman and Chief Executive Officer |

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## Exhibit 99.1

**Exhibit 99.1**

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| | |
|:---|:---|
| ![](tm262000d1_ex99-1img001.jpg) | ***NEWS RELEASE***<br> January 6, 2026 |

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**Tetra Tech to Appoint Roger Argus as Chief Executive Officer;**

**Dan Batrack to Become Executive Chairman**

*Pasadena, California.* <u>Tetra Tech, Inc.</u> (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services in water, environment, and sustainable infrastructure, announced today that Dan Batrack, Chairman, together with its independent Board of Directors, will appoint Roger Argus as Chief Executive Officer, effective February 19, 2026, concurrent with the Company's annual meeting of shareholders. At that time, Mr. Argus also is expected to join Tetra Tech's Board of Directors, and Mr. Batrack, currently Chairman and CEO, will transition to the role of Executive Chairman. This leadership change is the result of the Board's long-term succession planning process to ensure continuity of strategy, culture, and performance.

Mr. Argus has been with Tetra Tech for more than 30 years, most recently serving as President. He has played a central role in shaping the Company's strategic direction, guiding operational excellence, and leading major water, infrastructure, environmental, and emergency management programs for public- and private-sector clients. Mr. Argus has also been instrumental in expanding Tetra Tech's global presence and strengthening its technical capabilities through the integration of several strategic acquisitions. His deep understanding of the Company's markets, clients, and people positions him well to lead Tetra Tech into its next phase of global growth.

Mr. Batrack has served as CEO for more than 20 years and as Chairman of the Board since 2008, during which time Tetra Tech has grown from a predominantly U.S. based high-end consulting engineering company into a global leader with more than 25,000 employees and approximately $5 billion in annual revenue. Under his leadership, Tetra Tech advanced its *Leading with Science<sup>®</sup>* approach, expanded internationally, and delivered consistently strong financial and operational results. Mr. Batrack will serve as Executive Chairman for a minimum of two years and will continue to be engaged on the Company's long-term strategy and ensure a smooth transition, while Mr. Argus will assume leadership of the Company as the incoming CEO.

Kirsten M. Volpi, Lead Independent Director, said, "Our decision reflects the Board's rigorous succession planning process and strong confidence in Roger's ability to lead Tetra Tech forward. Roger has demonstrated exceptional leadership, technical expertise, and strategic insight throughout his career. Dan's vision and stewardship have transformed Tetra Tech into a global leader, and we are very pleased he will continue to provide insight as Executive Chairman. This transition positions the Company well for sustainable growth and long-term value."

"I am honored to serve as Tetra Tech's next CEO," said Roger Argus. "Dan has built a remarkable organization grounded in scientific excellence, innovation, and a performance-driven culture. As we look ahead, I am committed to advancing our *Leading with Science<sup>®</sup>* differentiation, deepening our global capabilities, and continuing to deliver impactful solutions for our clients and communities around the world."

Dan Batrack said, "It has been a privilege to serve as CEO and Chairman during a period of such extraordinary growth and transformation for Tetra Tech. I have worked closely with Roger for 30 years, and he is exceptionally well prepared to guide the Company into the future. I and Tetra Tech's Board look forward to supporting Roger and the Tetra Tech management team in further advancing Tetra Tech's mission and global impact."

**About Tetra Tech**

<u>Tetra Tech</u> is the leader in water, environment and sustainable infrastructure, providing high-end consulting and engineering services for projects worldwide. With more than 25,000 employees working together, Tetra Tech provides clear solutions to complex problems by *Leading with Science<sup>®</sup>* to address the entire water cycle, protect and restore the environment, and design sustainable and resilient infrastructure. For more information about Tetra Tech, please visit <u>tetratech.com</u> or follow us on <u>LinkedIn</u> and <u>Facebook</u>.

CONTACTS:

Jim Wu, Investor Relations

Charlie MacPherson, Media & Public Relations

(626) 470-2844

*Any statements made in this release that are not based on historical fact are forward-looking statements. Any forward-looking statements made in this release represent management's best judgment as to what may occur in the future. However, Tetra Tech's actual outcome and results are not guaranteed and are subject to certain risks, uncertainties and assumptions ("Future Factors"), and may differ materially from what is expressed. For a description of Future Factors that could cause actual results to differ materially from such forward-looking statements, see the discussion under the section "Risk Factors" included in the Company's Form 10-K and Form 10-Q filings with the Securities and Exchange Commission.*