# EDGAR Filing Document

**Accession Number:** 0000831641
**File Stem:** 0001104659-25-097567
**Filing Date:** 2025-10
**Character Count:** 10474
**Document Hash:** c9e54e2273514e8b58def30213878d76
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-097567.hdr.sgml**: 20251007

**ACCESSION NUMBER**: 0001104659-25-097567

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 14

**CONFORMED PERIOD OF REPORT**: 20251007

**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**: 20251007

**DATE AS OF CHANGE**: 20251007

**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:** 251380507

**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):

**October 7, 2025**

**TETRA TECH, INC.**

(Exact name of registrant as specified in its charter)

---

| | | |
|:---|:---|:---|
| **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:

---

| | | |
|:---|:---|:---|
| **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. ◻

---

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

---

*Appointment of Officer*

On October 7, 2025, Tetra Tech, Inc. (the "Company") announced that Roger R. Argus, Executive Vice President, Corporate Development, and President, Commercial/International Services Group, has been promoted to serve as the Company's President, reporting to Dan L. Batrack, Chairman and Chief Executive Officer. In this role, Mr. Argus will oversee the Company's global operations, working closely with senior leadership and operational teams to sustain the Company's exceptional performance and strategic growth.

Mr. Argus joined Tetra Tech more than 30 years ago, and has held increasingly responsible positions. He has served as Executive Vice President, Corporate Development since November 2024, and President, Commercial/International Services Group since October 2023. 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 served as project and program manager and business unit leader. He holds a Bachelor of Science in Chemical Engineering from California State University, Long Beach.

---

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

---

On October 7, 2025, 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.** |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d) Exhibits

[99.1](tm2528147d1_ex99-1.htm) [Press Release, dated October 7, 2025.](tm2528147d1_ex99-1.htm) <br>104 Cover Page Interactive Data File (embedded within the Inline XBRL document)

**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.

---

| | | |
|:---|:---|:---|
|  | TETRA TECH, INC. | TETRA TECH, INC. |
| Date: October 7, 2025 | By: | /s/ Dan L. Batrack |
|  |  | Dan L. Batrack |
|  |  | Chairman and Chief Executive Officer |

---

## Exhibit 99.1

**Exhibit 99.1**

---

| | |
|:---|:---|
| ![](tm2528147d1_ex99-1img001.jpg) |  |
| ![](tm2528147d1_ex99-1img001.jpg) | ***NEWS RELEASE*** |
| ![](tm2528147d1_ex99-1img001.jpg) | October 7, 2025 |
| ![](tm2528147d1_ex99-1img001.jpg) | |
| ![](tm2528147d1_ex99-1img001.jpg) |  |

---

**Tetra Tech Announces Leadership Appointments**

*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 two key leadership appointments as part of its continued succession planning and internal talent development. As we begin fiscal year 2026, Mr. Roger R. Argus is being promoted to President of Tetra Tech, and Mr. Jonathan S. Weiss will be appointed President, Commercial/International Services Group (CIG).

Mr. Argus, currently Executive Vice President of Corporate Development and President of the Commercial/International Services Group, brings 40 years of professional experience, including over 30 years with Tetra Tech. With an academic background in chemical engineering, Mr. Argus has led multidisciplinary environmental, engineering, and management programs across federal, state, municipal, and private clients. He has also directed Tetra Tech's mergers and acquisitions program through identifying, negotiating, and integrating companies that have further expanded our technical strength and client base. In his new role as President, Mr. Argus will oversee Tetra Tech's global operations, working closely with senior leadership and operational teams to sustain the Company's exceptional performance and strategic growth.

Mr. Weiss also brings more than 30 years' experience at Tetra Tech, leading operations across both federal and commercial markets, including growing our diversified energy practice. In his role as President of CIG, Mr. Weiss will continue to drive the Company's global water and energy nexus initiatives focused on the private sector.

"These appointments reflect the disciplined, forward-looking succession process we have undertaken," said Dan Batrack, Tetra Tech Chairman and CEO. "Mr. Argus' leadership, entrepreneurship and deep operational knowledge have contributed significantly to Tetra Tech's record of success. Together with Tetra Tech's executive management team, he will continue to advance our strategic objectives and industry-leading performance."

"It is a privilege to serve as President of Tetra Tech," said Roger Argus. "I look forward to building on our strong foundation of technical leadership, client trust, and collaboration. As we continue to expand globally, my focus will be on sustaining our exceptional performance and further advancing our ability to deliver innovative, science-based solutions for our clients worldwide."

These appointments build upon Tetra Tech's long-term commitment to continuity, operational excellence, and internal talent development. The Board of Directors and executive leadership congratulate both Mr. Argus and Mr. Weiss on their new appointments, as the Company continues its momentum into fiscal year 2026.

**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 30,000 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.*