Tetra Tech Wins $1 Billion USAID Water and Development Contract

Tetra Tech, Inc. (NASDAQ: TTEK) announced today it has been awarded a $1 billion multiple-award indefinite delivery indefinite quantity (IDIQ) contract for the U.S. Agency of International Development (USAID) to support the implementation of USAID’s Water and Development Strategy.

Under the five-year Water and Development IDIQ, Tetra Tech will support USAID in responding to increasing pressures on limited water resources from climate change, population growth, and energy demands, by providing engineering and consulting services to improve access to clean water and sanitation, and strengthen global food security through the sustainable management of water in agriculture. Tetra Tech will support in collecting and analyzing data to evaluate emerging water issues, develop water management strategies, and design innovative approaches to improve the delivery of water services in developing countries.

“Tetra Tech is pleased to continue supporting USAID in providing innovative solutions to address critical water issues around the world,” said Dan Batrack, Tetra Tech’s Chairman and CEO.

About Tetra Tech (www.tetratech.com)

Tetra Tech is a leading provider of consulting, engineering, program management, and construction management services. The Company supports commercial and government clients focused on water, environment, infrastructure, resource management, and energy. With 13,000 staff worldwide, Tetra Tech provides clear solutions to complex problems.

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.Jim Wu, Investor RelationsCharlie MacPherson, Media & Public Relations626-470-2844