TETRA TECH INC

Employees. At fiscal 2024 year-end, we had approximately 30,000 staff worldwide. A large percentage of our employees have technical and professional backgrounds and undergraduate and/or advanced degrees, including the employees of recently acquired companies. Our professional staff includes, but is not limited to, analysts, archaeologists, architects, biologists, chemical engineers, chemists, civil engineers, data scientists, computer scientists, digital engineers, economists, electrical engineers, environmental engineers, environmental scientists, geologists, hydrogeologists, mechanical engineers, software engineers, statisticians, oceanographers, project managers and toxicologists. We consider the current relationships with our employees to be favorable. We are not aware of any employment circumstances that are likely to disrupt work at any of our facilities. See Part I, Item 1A, "Risk Factors" for a discussion of the risks related to the loss of key personnel or our inability to attract and retain qualified personnel.

Health and Safety. Tetra Tech is committed to providing and maintaining a healthy and safe work environment for our associates. We provide training to all associates to support the safe execution of their work to improve their understanding of behaviors that can be perceived as discriminatory, exclusionary and/or harassing, and provide safe avenues for associates to report such behaviors.

Ethics and Compliance. Tetra Tech maintains an unwavering commitment to integrity, ethical practices, and conducting business in full compliance with the law. Our Code of Business Ethics and Conduct outlines the general ethical principles that help us make the right decisions when conducting business worldwide. To support our employees, we provide a variety of resources and trainings and offer multiple avenues to raise questions or concerns - to help ensure long-term success for our employees, company, clients, and shareholders.

Diversity, Equity, Inclusion and Accessibility. Tetra Tech brings together engineers and technical specialists from all backgrounds to solve our clients' most challenging problems. Our Diversity, Equity, Inclusion and Accessibility ("DEIA") Policy guides the Board of Directors, management, associates, subcontractors and partners in developing an inclusive culture. Our DEIA Council monitors Tetra Tech's diversity, equity, inclusion and accessibility practices and makes recommendations to the Board of Directors and Chief Executive Officer for any changes or improvements to our program.

Tetra Tech values diversity, equity, inclusion and accessibility and undertakes various efforts throughout its operations to promote these initiatives. Our current efforts are focused on these primary areas:

•Equal employment opportunity. Tetra Tech ensures that our practices and processes attract a diverse range of candidates and that candidates are recruited, hired, assigned, developed and promoted based on merit and their alignment with our values.

•Enhancing learning and development opportunities. To support our employees in reaching their full potential, Tetra Tech offers a wide range of internal and external learning and development opportunities. Education assistance is offered to financially support associates who seek to expand their knowledge and skill base.

As part of Tetra Tech's commitment to a culture of inclusion, our Employee Resource Group ("ERG") Program broadens and enhances company-wide interaction opportunities for our employees. Tetra Tech's ERGs are open to all associates and involve activities for both employees whose background is the focus of the ERG and those who are supportive of the group (also known as allies). These global networks build on and coordinate with the many local networks that are already active throughout our operations and include groups focused on the experiences of Black, Latino, Pan-Asian, Women, Veterans, Disabled and LGBTQIA+ employees and emerging professionals.

Professional Development. Tetra Tech provides access for all employees to training, technical exchange and collaboration, and skill development resources through its customized Learning Management System, providing professional development opportunities throughout our employees' careers. Technology skills development includes access to a series of live webcasts and recorded technology transfer sessions. Company-wide networking events provide interactive skills development activities. Employees are also provided with access to training in leadership development, project management skills, and interpersonal skills development. Various personal development and wellness programs are sponsored by our Human Resources team. Our Corporate Information Technology team provides access to software training and skills development modules to all employees. Tetra Tech also supports our employees in discipline specific training, certifications, and accreditation programs across the Company. Programs such as specific health and safety programs, hazardous waste investigation, environmental certifications, and professional certifications are encouraged as per client, project and professional development needs.