Carollo Engineers

Carollo Engineers is an environmental engineering firm based in Walnut Creek, California, with a history dating back to 1933. The company specializes in the planning, design, construction, and management of water and wastewater facilities across North America. With over 45 offices and approximately 1,400 employees, Carollo is recognized as the largest U.S. firm dedicated solely to water-related engineering, generating around $270 million in annual revenue. The firm offers a wide range of services, including drinking water solutions, wastewater management, climate change resilience planning, and stormwater drainage master planning. Carollo collaborates closely with clients to provide innovative, data-driven solutions that address municipal and environmental needs. Their expertise includes the development of water treatment facilities, wastewater treatment plants, and integrated water resource management, all aimed at promoting sustainability and regulatory compliance. Carollo Engineers has established long-term partnerships with municipalities, including a notable relationship with the City of Phoenix.