1. Featured Firm Presentation SAME Luncheon February 10, 2010 www.tetratech.com

2. Offices and Staff Customers and Peers Business Segments 2

3. Business Overview  Consulting, Engineering, and Project Management Services 3  $2.3B Revenue in FY09  More than 10,000 Employees Worldwide 75% Water & Environment 15% Infrastructure 10% Energy in past 5 years

4. 4 Tetra Tech Office Locations U.S. Presence

5. International Office Locations

6. 6 Top Clients (by net rev.) % U.S. FEDERAL U.S. AID9.2 U.S. Army COE8.7 U.S. Navy7.4 U.S. DOD – Other4.6 U.S. EPA3.4 U.S. STATE & LOCAL 15.3 U.S. COMMERCIAL PacifiCorp (Wind)3.1 Invenergy/Sheldon1.8 Fox River LLC1.4 Carson Marketplace LLC1.2 Verizon1.2 INT’L Canada (FY09E) 4.0 Other (FY09E) 1.0 Customers & Peers (FY09)

7. Market Differentiator Construction Project Management Engineering Science Project Size Technical Barrier to Entry High Low Margin High Low Market Entry Point 7

8. Segment Mix (FY09) 8 31% Remediation & Construction Mgmt. (RCM) Segments 27% Environmental Consulting Services (ECS) 19% Engineering & Architecture Services (EAS) 23% Technical Support Services (TSS) % of Revenue, Net of Subcontractor Costs Project Phases Study Advise Design Build ECS TSS EAS RCM Entry Point

9. Environmental A-E Services Environmental Remediation Energy Management Infrastructure 9

10. Environmental A-E and Remediation Services (NAVFAC SW and BRAC) More than $2 billion in completed environmental restoration projects at 80 Navy installations over 15 years

11. Energy Management Services The Leading Provider of Resource Efficiency Management (REM) Services to the Navy

12. Greg Swanson, Ph.D., P.E. Tetra Tech EMI 1230 Columbia St., Suite 1000 San Diego, CA 92101 619-525-7188 greg.swanson@tetratech.com Thank You