Tetra Tech and International Resources Group Joint Venture Awarded Indian Ocean Tsunami Warning System Development Project.

PASADENA, Calif. -- Tetra Tech, Inc. (NASDAQ:TTEK) announced today that its joint venture with International Resources Group (IRG) was awarded a two-year, $6 million task order under the worldwide water resources contract with the U.S. Agency for International Development (USAID). USAID is leading the U.S. government assistance program to support the development of an Indian Ocean Tsunami Warning System (IOTWS), in coordination with the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization, other donor nations, and national governments in the region.

Li-San Hwang, Tetra Tech's Chairman and CEO, said: "Tetra Tech has done substantial work in the field of tsunami research. We are pleased to be given this opportunity to again make a contribution for society's benefit and to minimize human losses in the event of such catastrophic disasters."

"IRG is pleased to support USAID in assisting the people of East Asia to develop an effective tsunami early warning system that will help prevent massive loss of life as occurred in that region last December. Our intention is to build a system that also detects other destructive natural disasters, from floods to droughts, and includes monitoring and prediction elements, a communications process for disseminating warning messages and information to prepare and act," said Asif Shaikh, International Resources Group President and CEO. "To this end, we look forward to working with our exceptional team of experts on USAID's behalf."

The United States is the only country in the world besides Japan that has built and operated an "end-to-end" tsunami early warning system. U.S. activities will support each of the essential elements of an IOTWS, including: risk assessment; hazard monitoring, detection and prediction; formulation, dissemination and communication of warning messages; and knowledge and preparedness to act. The program will provide targeted technical support to Indonesia, Sri Lanka, India, Thailand and the Maldives in developing and implementing various components of an IOTWS at national and local levels.

Under this task order, the joint venture will serve as the Program Integrator, providing technical assistance, coordination, logistics, training and administrative support to USAID's Regional Development Mission/Asia and to international, national and local organizations involved in the development of an IOTWS. The joint venture will provide overarching services and coordination support to the National Oceanic and Atmospheric Administration, U.S. Geological Survey, U.S. Trade and Development Agency, and U.S. Forest Service.

About International Resources Group Ltd. (www.irgltd.com)

IRG is an international professional services firm that helps governments, the private sector, communities and households manage critical resources to build a cleaner, safer and more prosperous world. Since its inception in 1978, IRG has completed over 650 contracts in 134 countries, delivering high-quality, cost-effective services that promote positive economic growth, institutional and social change, and intelligent use of resources -- human, physical, environmental and financial.

About Tetra Tech (www.tetratech.com)

Tetra Tech is a leading provider of consulting, engineering and technical services. With nearly 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, program management, 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.