PASADENA, Calif.- Tetra Tech, Inc. (NASDAQ: TTEK) announced today that it has signed a definitive agreement to acquire Norman Disney & Young (NDY), a leader in sustainable infrastructure engineering design. Established in 1959, NDY maintains offices throughout Australia, the Asia-Pacific region, the United Kingdom, and Canada. NDY incorporates innovative technologies and solutions into designs, helping to create environments that use less energy, recycle water, and provide safe and sustainable infrastructure.

“The addition of NDY to our sustainable infrastructure design practice will enable Tetra Tech to offer technically differentiated solutions to our commercial and government clients on a global scale,” said Dan Batrack, Tetra Tech’s Chairman and CEO. “NDY will join our high-end design team in the United States to provide worldwide coverage and complementary client relationships.”

“We are very excited to join Tetra Tech,” said Stuart Fowler, NDY’s CEO. “Tetra Tech expands our ability to provide our high-end services, provides opportunity for technical collaboration, and adds new clients. We look forward to further developing the science of sustainable design and providing industry-leading technical solutions.”

NDY is joining the Commercial and International Business Group’s Asia Pacific operations. The acquisition will be subject to the satisfaction of customary closing conditions.

About Norman Disney & Young

NDY is a global engineering design firm of more than 700 professionals operating across 13 offices in Australia, the United Kingdom, New Zealand, Hong Kong, and Canada. NDY provides sustainable engineering design services for the built environment, including commercial offices, education, health, industrial, mission critical, residential & hotels, retail and transport facilities. For more information about NDY, please visit ndy.com.

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 more than 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.