Tetra Tech Completes Three Acquisitions With Combined Revenue of $85 Million

Tetra Tech, Inc. (NASDAQ: TTEK) announced today that it has acquired three companies that expand its geographic coverage and technical services. Tesoro Corporation (Tesoro) is a construction management firm that works primarily for the U.S. Department of Defense (DoD) on Base Realignment and Closure (BRAC) and military construction programs. Based in Virginia Beach, Virginia, Tesoro has revenue of approximately $80 million per year.

"Tesoro holds over $500 million in contract capacity that will help improve Tetra Tech’s positioning for certain DoD economic stimulus projects,” said Dan Batrack, Tetra Tech’s Chairman and CEO. "We have a long and successful teaming relationship with Tesoro, and we believe it is the right time for this combination. We welcome all of the employees of Tesoro.”

Tetra Tech also recently acquired and integrated two highly specialized companies. Mussetter Engineering of Fort Collins, Colorado, provides expertise in water resources, fluvial geomorphology, and environmental hydraulics. ACI Engineering of Vancouver, British Columbia, provides high voltage power engineering to support energy transmission. Together, Mussetter Engineering and ACI Engineering have about $5 million in annual revenue.

Tetra Tech did not disclose the terms of the acquisitions.

About Tetra Tech (www.tetratech.com)

Tetra Tech is a leading provider of consulting, engineering, program management, construction, and technical services addressing the resource management and infrastructure markets. The Company supports government and commercial clients by providing innovative solutions focused on water, the environment, and energy. With more than 10,000 employees worldwide, Tetra Tech’s capabilities span the entire project life cycle.

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 10-Q filings with the Securities and Exchange Commission.