Tetra Tech Board Elects Albert Smith as Vice Chairman

Mr. Smith is a former member of the Secretary of Defense's DefenseScience Board, serving from 2002 to 2005. He was an Executive VicePresident of Lockheed Martin and President of its Integrated Systems &Solutions business until 2004. From 1999 to 2003, Mr. Smith wasPresident of Lockheed Martin's Space Systems Company. Prior to that,Mr. Smith was President of Government Systems at Harris Corporation.He has also worked for the Central Intelligence Agency, where hereceived the Intelligence Medal of Merit. Mr. Smith has served asChairman of International Launch Services' Board of Directors and as aDirector of the Space Foundation.

Li-San Hwang, Tetra Tech's Chairman and CEO, said, "Mr. Smith'smanagement experience at Lockheed Martin will help us strengthen ourbusiness processes and position Tetra Tech to become a multi-billiondollar company. He will work closely with the management team on bothstrategic and operational decisions."

About Tetra Tech (www.tetratech.com)

Tetra Tech is a leading provider of consulting, engineering andtechnical services. With nearly 8,000 associates located in the UnitedStates and internationally, the Company supports commercial andgovernment clients in the areas of resource management, infrastructureand communications. Tetra Tech's services include research anddevelopment, applied science and technology, engineering design,program management, construction management, and operations andmaintenance.

Any statements made in this release that are not based onhistorical fact are forward-looking statements. Any forward-lookingstatements made in this release represent management's best judgmentas to what may occur in the future. However, Tetra Tech's actualoutcome and results are not guaranteed and are subject to certainrisks, uncertainties and assumptions ("Future Factors"), and maydiffer materially from what is expressed. For a description of FutureFactors that could cause actual results to differ materially from suchforward-looking statements, see the discussion under the section "RiskFactors" included in the Company's Form 10-K and 10-Q filings with theSecurities and Exchange Commission.