Los Angeles Business Journal ranked Tetra Tech as the #1 Environmental Engineering and Consulting Firm in Los Angeles County for 2018. With headquarters in Pasadena, California, Tetra Tech was founded in 1966 and has grown to 522 employees in Los Angeles County, with 17,000 employees and 400 offices worldwide. Led by CEO and Chairman Dan Batrack, Tetra Tech’s full-service work includes expertise in water, environment, infrastructure, resource management, energy, and international development.