Let Tetra Tech NUS do your dirty work. The firm provides environmental consulting, engineering, and remediation services. Its expertise extends to such areas as air quality management, compliance services, environmental analysis and planning, health sciences, homeland security, information technology, radioactive and hazardous waste investigation and protection, and water and wastewater treatment. Now part of engineering giant Tetra Tech, the company stemmed from nuclear utility consulting and engineering firm Nuclear Utility Services Corporation (NUS Corporation), which was founded in 1960. Clients, including government agencies and commercial industries, are served through 17 offices across the US.