Tetra Tech is a consulting and engineering firm focused on water infrastructure, environmental services, and related sustainable infrastructure. Water projects make up roughly 85% of Tetra Tech's work. Customers include federal and local governments, defense agencies, utilities, and industrial companies that need to plan, design, build, or manage water systems, environmental remediation, and resilient infrastructure. Tetra Tech operates through two roughly equal segments: the Government Services Group (GSG), which serves U.S. federal, state, and local governments and international development agencies; and the Commercial/International Services Group (CIG), which serves U.S. commercial clients and international clients, primarily in Australia, Canada, the U.K., and Ireland. Tetra Tech bills clients under fixed-price, time-and-materials, and cost-plus contracts, with management deliberately pushing toward more fixed-price work, which offers the highest margin upside. Margin expansion is driven by shifting mix toward higher-margin front-end consulting work, increasing fixed-price penetration, and deploying proprietary digital tools and AI to deliver work more efficiently. Tetra Tech also maintains over 500 emergency response contracts with state and local governments, making disaster response an episodic but high-margin revenue contributor. Acquisitions are a core part of Tetra Tech's growth strategy, targeting companies in the 100–1,000 employee range that add technology, geography, or client access, with recent deals including RPS Group in the U.K. and SAGE Group Automation in Australia.