TETRA TECH INC (TTEK) Business

Item 1.    Business

General

Tetra Tech, Inc. ("Tetra Tech") is a leading global provider of high-end consulting and engineering services that focuses on water, environment and sustainable infrastructure. We are a global company that is Leading with Science® to provide innovative solutions for our public and private clients. We typically begin at the earliest stage of a project by identifying technical solutions and developing execution plans tailored to our clients' needs and resources.

Tetra Tech is Leading with Science® to provide sustainable and resilient solutions to our clients' most complex needs. Engineering News-Record ("ENR"), the engineering industry's leading magazine, has ranked Tetra Tech #1 in Water Treatment and Desalination for 12 years in a row. In 2025, we were also ranked #1 in consulting studies, environmental management, environmental science, wind power, hydro plants, site assessment and compliance, and green government offices. ENR also ranked Tetra Tech in the Top 10 in numerous categories, including dams and reservoirs, marine and port facilities, power, solar power, solid waste, chemical and soil remediation, and hazardous waste.

Our reputation for high-end consulting and engineering services and our ability to develop solutions for water and environmental management has supported our growth for more than 50 years. Our market leading climate mitigation and adaptation services are solving our clients' most complex challenges related to coastal flooding, water security, energy transition and biodiversity protection. Today, we are proud to be making a difference in people’s lives worldwide through our high-end consulting, engineering and technology service offerings. In fiscal 2025, we worked on over 100,000 projects, in more than 100 countries on all seven continents, with more than 25,000 associates. We are Leading with Science® throughout our operations, with domain experts across multiple disciplines supported by our advanced analytics, artificial intelligence ("AI"), machine learning and digital technology solutions. Our ability to provide innovative and first-of-kind solutions is enhanced by partnerships with our forward-thinking clients. We embrace the breadth of experience across our talented workforce worldwide with a culture of innovation and entrepreneurship. We are disciplined in our business, and focused on delivering value to customers and high performance for our shareholders. In supporting our clients, we seek to add value and provide long-term sustainable consulting, engineering and technology solutions.

Our mission is to be the world's leading consulting and engineering firm solving global challenges in water and the environment that make a positive difference in people's lives worldwide.

The following core principles form the underpinning of how we work together to serve our clients:

•Service.  We put our clients first. We listen closely to better understand our clients' needs and deliver smart, cost-effective solutions that meet their needs.

•Value.  We solve our clients' problems as if they were our own. We develop and implement sustainable solutions that are innovative, efficient and practical.

•Excellence.  We bring superior technical capability, disciplined project management and excellence in safety and quality to all of our services.

•Opportunity.  Our people are our number one asset. Opportunity means new technical challenges that provide advancement within our company and ensure a safe workplace.

We have a strong project management culture that enables us to deliver on more than 100,000 projects per year. Our client-focused project management is supported by strong fiscal management and financial tools. We use a disciplined approach

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to monitoring, managing and improving our return on investment in each of our business areas through our efforts to negotiate appropriate contract terms, manage our contract performance to minimize schedule delays and cost overruns, and promptly bill and collect accounts receivable.

We have built a broad client and contract base by proactively understanding our clients' priorities and demonstrating a long track record of successful performance that results in repeat business and limits competition. We believe that proximity to our clients is also instrumental to integrating global experience and resources with an understanding of our local clients' needs.

Throughout our history, we have supported both public and private clients, many for multiple decades of continuous contracts and repeat business. Long-term relationships provide us with institutional knowledge of our clients' programs, past projects and internal resources. Institutional knowledge is often a significant factor in winning competitive proposals and providing cost-effective solutions tailored to our clients' needs.

We are often at the leading edge of new challenges where we are delivering one-of-a-kind solutions. These might be a new water treatment technology, a unique solution to addressing coastal erosion, an AI-enabled system for remote assessment of infrastructure assets or real-time optimization of water management systems.

We combine interdisciplinary capabilities, technical resources and institutional knowledge to implement complex projects that are at the leading edge of policy and technology development for our clients around the world.

Leading with Science®

At Tetra Tech, we provide value-generating solutions by combining operational expertise, science and technology. By Leading with Science® and leveraging our collective technology including advanced data analytics, digital technologies and AI, we create transformational solutions for our clients.

Tetra Tech's proprietary technologies and solutions, referred to collectively as the Tetra Tech Delta, differentiate us in the market and provide us with a competitive advantage. We create customized solutions; from smart data collection and advanced analytics that support decision making to AI-enabled solutions for asset management. Our Tetra Tech Delta technologies are drawn from our decades of operational experience and a reservoir of technical applications that are shared throughout our company as well as scalable solutions that are sold externally as software subscriptions. Our high-end teams connect interdisciplinary experts from across our company's more than 25,000 staff worldwide. Tetra Tech mobilizes teams that include analysts, statisticians, digital engineers and industry experts who effectively implement value-generating and pragmatic solutions for our clients.

These advanced analytical solutions enable us to provide clients with real-time reporting, automated and remote data collection and dashboards for tracking and communicating results. Tetra Tech Delta is continually expanding and includes cutting-edge tools on interpretive analysis, modeling of physical systems, forecasting and scenario analysis, optimization and operations research. Our subscription solutions provide our clients with extended capabilities for AI-enabled large scale data management, spatial data interpretation, and ability to optimize land, coastal and infrastructure systems.

Leading with Science® also means fully leveraging the collective expertise provided by our global workforce of more than 25,000 associates. We actively share information, ideas and resources across our global operations through our network structure, guided subject matter teams and project team building. We use company-wide virtual events to engage Tetra Tech experts world-wide to solve client challenges and identify the best ideas for further development. We also proactively share emerging technology and new ideas through our knowledge transfer system, Tetra Tech Technology Transfer ("T4"). T4 facilitates our innovation culture through webcasts, blogs, multi-media and social media across our global operations. Our Tetra Tech Learning Hub provides a full suite of training resources including project management, leadership development, and broad technical skills. Learning Hub curriculum is provided through online training, virtual workshops and in-person events.

Reportable Segments

We manage our operations under two reportable segments. Our Government Services Group ("GSG") reportable segment primarily includes activities with U.S. government clients (federal, state and local) and all activities with development agencies worldwide. Our Commercial/International Services Group ("CIG") reportable segment primarily includes activities with U.S. commercial clients and international clients other than development agencies. These reportable segments allow us to capitalize on our growing market opportunities and enhance the development of high-end consulting and technical solutions to meet our growing client demand.

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The following table presents the percentage of our revenue by reportable segment: