U.S. EPA Office of Research and Development Awards Tetra Tech $60 Million Environmental Assessment Contract

PASADENA, Calif.–(BUSINESS WIRE)–Tetra Tech, Inc. (NASDAQ: TTEK) announced today that the U.S.
Environmental Protection Agency’s Office of Research and Development
(ORD) awarded the Company a contract valued at $60 million. Under this
five-year, single-award contract, Tetra Tech will provide comprehensive
technical and analytical services to evaluate ecological and human
health risks in freshwater, marine, and terrestrial ecosystems.

Tetra Tech’s researchers will provide technical support services to
ORD’s National Center for Environmental Assessment to develop and
evaluate tools that are used by decision-makers in safeguarding public
health and the environment. These tools include dynamic water quality,
biogeochemical, and pollutant transport models that simulate impacts
ranging from large scale global changes as well as regional and local
land-use changes and best management practices. Tetra Tech will perform
statistical, economic, and spatial analyses to assess vulnerability and
resilience to various environmental factors. In addition, Tetra Tech
will design and maintain databases that support digital access and data
analytics to facilitate analyses by ORD scientists.

“For over 30 years, Tetra Tech has supported EPA’s research programs,”
said Dan Batrack, Tetra Tech Chairman and CEO. “We are pleased to
continue our support of the EPA by developing innovative methods
grounded in science that protect public health and the environment.”

About Tetra Tech

Tetra Tech is a leading, global provider of consulting and engineering
services. We are differentiated by Leading with Science^®
to provide innovative technical solutions to our clients. We support
global commercial and government clients focused on water, environment,
infrastructure, resource management, energy, and international
development. With 16,000 associates worldwide, Tetra Tech provides clear
solutions to complex problems. For more information about Tetra Tech,
please visit tetratech.com,
follow us on Twitter (@TetraTech),
or like us on Facebook.

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.

Contacts

Tetra Tech, Inc.
Jim Wu, Investor Relations
Charlie
MacPherson, Media & Public Relations
(626) 470-2844