2009-11-24 15:18:03 -

Tetra Tech, Inc. (NASDAQ: TTEK) announced today that it has been awarded a $63 million task order to provide architect/engineering (A/E) services for the U.S. Agency for International Development (USAID) in support of sustainable infrastructure development programs in Afghanistan. This five-year program is Tetra Tech’s first major award under the USAID global A/E infrastructure services contract announced in October 2008.

“At

this critical time in America’s involvement with Afghanistan, Tetra Tech is pleased to support USAID’s mission in the country,” said Dan Batrack, Tetra Tech’s CEO and Chairman.

Working with the USAID Office of Infrastructure, Engineering, and Energy, Tetra Tech will identify, plan, design, and provide engineering support for urban and rural water supply and sanitation systems; vertical structures including schools and government facilities; power transmission and generation projects; and transportation systems, among other development-related projects nationwide.

The American people, through the USAID, have provided economic and humanitarian assistance worldwide for nearly 50 years.



About USAID: For more information, please visit USAID’s website at www.usaid.gov : .



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 approximately 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.

Tetra Tech, Inc.Jorge Casado, Investor RelationsTalia

Starkey, Media & Public Relations626-470-2844