Pasadena-Based Global Consulting, Engineering Firm Tetra Tech Appoints New President

Tetra Tech Inc., a global consulting and engineering firm headquartered in Pasadena, announced two senior leadership appointments Tuesday as part of its continued succession planning and internal talent development.

Roger R. Argus, currently executive vice president of corporate development and president of the Commercial/International Services Group (CIG), has been promoted to president of Tetra Tech. Jonathan S. Weiss will assume the role of president of CIG. The appointments coincide with the start of the company’s Fiscal Year 2026.

“These appointments reflect the disciplined, forward-looking succession process we have undertaken,” said Dan Batrack, Tetra Tech chairman and CEO, in a company statement. “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.”

Argus brings 40 years of professional experience, including over 30 years with Tetra Tech. He has led multidisciplinary environmental, engineering, and management programs across federal, state, municipal, and private clients, and directed the company’s mergers and acquisitions program through identifying, negotiating, and integrating companies that have further expanded its technical strength and client base. In his new role, 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.

Weiss also brings more than 30 years’ experience at Tetra Tech, leading operations across both federal and commercial markets, including growing the company’s diversified energy practice. As president of CIG, Weiss will continue to drive the company’s global water and energy nexus initiatives focused on the private sector.

According to the company’s announcement, 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 congratulated both Argus and Weiss on their new appointments as the company continues its momentum into Fiscal Year 2026.

Tetra Tech employs 30,000 people worldwide and provides consulting and engineering services focused on water, the environment, and sustainable infrastructure. Its headquarters in Pasadena remains central to its global operations and strategic identity. The company describes its mission as “Leading with Science®” to address the entire water cycle, protect and restore the environment, and design sustainable and resilient infrastructure.