Langan Treadwell Rollo is a certified Bay Area Green Business, providing environmental, geotechnical, site/civil and earthquake engineering services from our Northern California offices in San Francisco, Oakland, Sacramento, and San Jose. As a member of Langan Engineering & Environmental Services, a privately held consulting firm headquartered in Elmwood Park, New Jersey, Langan has access nearly 800 employees in additional offices located located throughout the world. Langan Treadwell Rollo provides practical and cost-effective solutions for the problems and challenges faced by our clients. We are proud of our past and confident about our future and we look forward to continuing to help our clients achieve the best results for their projects. Our guiding principles are: high-quality technical work practical, cost-effective solutions responsive and timely service