Carollo Engineers, Inc.

Carollo Engineers, Inc. is an environmental engineering consulting firm in the United States specializing exclusively in water and wastewater infrastructure planning, design, and construction management. Founded in 1933, the firm serves municipal utilities, public agencies, and private sector clients with specialized water engineering solutions. Its core services encompass drinking water treatment, wastewater reclamation, stormwater management, water reuse, and asset management consulting. Carollo also delivers technical capabilities in digital water services, electrical programming and instrumentation control, and PFAS assessment and treatment technologies. The company operates more than 60 office locations across North America, including key offices in California, Arizona, Texas, Florida, and Washington. Through advanced initiatives like the Carollo Research Group and Water Applied Research Center, the firm develops decision support tools such as Blue Plan-It and treatment innovations like XBAT. As an engineering and program management partner, Carollo collaborates with water utilities to modernize aging infrastructure and execute capital expansion projects. With over 1,900 employees, the firm offers comprehensive utility advisory services, environmental regulatory compliance assistance, and operational support nationwide.