Tetra Tech, Inc. engages in the provision of consulting and engineering services that focus on water, environment, infrastructure, renewable energy, and international development. It operates through the following segments: Government Services Group (GSG) and Commercial and International Services Group (CIG). The GSG segment offers consulting and engineering services primarily to United States government clients such as federal, state and local, and development agencies worldwide. The CIG segment provides consulting and engineering services to US commercial clients and international clients inclusive of the commercial and government sectors, as well as infrastructure, environmental, engineering, and project management services across Canada, Australia, New Zealand, the United Kingdom, Brazil, and Chile. The company was founded in 1966 and is headquartered in Pasadena, CA.