> Enrich.chat gives AI agents verified work emails and mobiles. To use it from an agent, read https://enrich.chat/agents.md . This is the Markdown version of https://enrich.chat/company/tetra-tech/ # Tetra Tech A civil engineering organization with 25,000 to 50,000 employees. Where it sits among its peers, the technology it runs and how to reach its people. By Enrich.chat Editorial. Updated October 21, 2026. **Short answer:** Tetra Tech (tetratech.com) is a civil engineering organization with 25,000 to 50,000 employees. Its public technology footprint includes Microsoft 365, Microsoft Outlook, Salesforce and Zendesk. ## How big is Tetra Tech? Tetra Tech has 25,000 to 50,000 employees. Among the civil engineering firms on this site it sits among the largest. Each dot in the figure is one of its peers, placed by size; the orange dot is Tetra Tech. **Figure: Where Tetra Tech sits among civil engineering firms.** A strip of dots, one for each of 66 peers in civil engineering, spread from 2,000 to 2,000,000 employees on a log scale. Tetra Tech is highlighted and falls in the 25,000 to 50,000 employees range among the largest. *Peers in civil engineering placed by employee count on a log scale. Sizes are rounded ranges from public profiles.* Headcount on public company profiles is rounded and moves as a company hires, so use the range as a guide, not as a payroll figure. ## Where is Tetra Tech headquartered? Tetra Tech is headquartered in Pasadena, California. [Companies in California](https://enrich.chat/companies-in/california/) ## What industry is Tetra Tech in? Tetra Tech works in [civil engineering](https://enrich.chat/industries/civil-engineering/). This group covers firms that design and oversee roads, bridges, water systems and other public and private infrastructure. Similar organizations on this site: [Downer](https://enrich.chat/company/downer/), [Ferrovial](https://enrich.chat/company/ferrovial/), [Mott MacDonald](https://enrich.chat/company/mott-macdonald/), [Parsons](https://enrich.chat/company/parsons/), [Egis](https://enrich.chat/company/egis/) and [OEC](https://enrich.chat/company/oec/). ## What technology does Tetra Tech use? We detect 14 tools on Tetra Tech's public footprint across 8 categories, for example Salesforce for marketing automation and crm, Flywheel for cloud and hosting and Zendesk for customer support and chat. The figure counts the tools in each category; the groups below name them and link to the companies that use each one. **Figure: Tools detected at Tetra Tech, by category.** A bar chart of how many tools were detected at Tetra Tech in each category: Email and productivity 3, Marketing automation and CRM 2, Customer support and chat 2, Data and observability 2, Cloud and hosting 1, HR and recruiting 1, Developer and DevOps tools 1. *Tools detected on the public footprint of Tetra Tech, by category.* ### Marketing automation and CRM [Salesforce](https://enrich.chat/companies-using/salesforce/)[HubSpot](https://enrich.chat/companies-using/hubspot/) ### Cloud and hosting [Flywheel](https://enrich.chat/companies-using/flywheel/) ### Customer support and chat [Zendesk](https://enrich.chat/companies-using/zendesk/)[Salesforce Live Agent](https://enrich.chat/companies-using/salesforce-live-agent/) ### HR and recruiting [Oracle Taleo](https://enrich.chat/companies-using/taleo/) ### Data and observability [Microsoft Application Insights](https://enrich.chat/companies-using/microsoft-application-insights/)[Microsoft Power BI](https://enrich.chat/companies-using/microsoft-power-bi/) ### Developer and DevOps tools [Python](https://enrich.chat/companies-using/python/) ### Email and productivity [Microsoft 365](https://enrich.chat/companies-using/microsoft-365/)[Microsoft Outlook](https://enrich.chat/companies-using/microsoft-outlook/)[Mailchimp SPF](https://enrich.chat/companies-using/mailchimp-spf/) Tools change as companies adopt and drop them. Check a single company at any time with the free [tech stack lookup](https://enrich.chat/tools/tech-stack-lookup/). ## How do I find the right people at Tetra Tech? Start from the website, tetratech.com. Enter it in the free email finder with a name, or ask your AI agent for the people in the roles you sell to, such as principals, project directors and heads of business development. ```text Use www.enrich.chat to find the principals, project directors and heads of business development at tetratech.com, with titles and verified work emails ``` Staff addresses follow a known pattern: see the [Tetra Tech email format](https://enrich.chat/email-format/tetra-tech/). ## Which other companies use the same tools? See who else runs the tools Tetra Tech uses: [Microsoft 365](https://enrich.chat/companies-using/microsoft-365/)[Microsoft Outlook](https://enrich.chat/companies-using/microsoft-outlook/)[Salesforce](https://enrich.chat/companies-using/salesforce/)[Zendesk](https://enrich.chat/companies-using/zendesk/)[HubSpot](https://enrich.chat/companies-using/hubspot/)[Salesforce Live Agent](https://enrich.chat/companies-using/salesforce-live-agent/) ## Frequently asked questions ### How many employees does Tetra Tech have? Tetra Tech is in the 25,000 to 50,000 employees range on its public company profile. Headcounts are rounded and change as companies hire, so treat the range as a guide. ### What industry is Tetra Tech in? Tetra Tech works in civil engineering. This group covers firms that design and oversee roads, bridges, water systems and other public and private infrastructure. ### What technology does Tetra Tech use? Tools detected on its public footprint include Microsoft 365, Microsoft Outlook, Salesforce and Zendesk, across 8 categories. A detected tool shows it was seen, not what Tetra Tech pays for it. ### Where is Tetra Tech headquartered? Tetra Tech is headquartered in Pasadena, California. ### What is the website of Tetra Tech? Tetra Tech's website is tetratech.com. Staff email usually uses a domain like it, so check the pattern with the free email format finder before you write to anyone. ## Try this prompt Find people at Tetra Tech ```text Use www.enrich.chat to find the principals, project directors and heads of business development at tetratech.com, with titles and verified work emails ``` ## Related - [Companies using a technology](https://enrich.chat/companies-using/) - [Downer](https://enrich.chat/company/downer/) - [Ferrovial](https://enrich.chat/company/ferrovial/) - [Mott MacDonald](https://enrich.chat/company/mott-macdonald/) - [Parsons](https://enrich.chat/company/parsons/) - [Egis](https://enrich.chat/company/egis/) - [OEC](https://enrich.chat/company/oec/) - [Ramboll](https://enrich.chat/company/ramboll/) - [Epiroc](https://enrich.chat/company/epiroc/) - [Tech stack lookup](https://enrich.chat/tools/tech-stack-lookup/)