Tetra Tech Inc provides consulting and engineering services for environmental, infrastructure, resource management, energy, and international development markets. It specializes in providing water-related services for public and private clients. It designs infrastructure, facilities, and other structures with complex plans and resource management. Tetra Tech has two reportable segments. Its Government Services Group (GSG) reportable segment primarily includes activities with U.S. government clients (federal, state and local) and activities with development agencies worldwide. Commercial/International Services Group (CIG) reportable segment primarily includes activities with U.S. commercial clients and international clients other than development agencies.