Tetra Tech Awarded New DOE Environmental Contract.

PASADENA, Calif. -- Tetra Tech, Inc. (NASDAQ:TTEK) announced today that it will perform Environmental Remediation/Waste Management (ER/WM) services under a 5-year contract awarded by the U.S. Department of Energy (DOE). The infinite delivery/indefinite quantity contract has an $800 million ceiling

The objective of the ER/WM services contract is to accelerate cleanup initiatives by providing soil and groundwater characterization and waste management at current or former DOE sites. Waste types can include radiological, solid and hazardous materials. The Company has been providing services to the DOE for more than 30 years.

About Tetra Tech (www.tetratech.com)

Tetra Tech is a leading provider of consulting, engineering and technical services. With over 8,000 associates located in the United States and internationally, the Company supports commercial and government clients in the areas of resource management, infrastructure and communications. Tetra Tech's services include research and development, applied science and technology, engineering design, construction management, and operations and maintenance.

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.