Since the founding of Carollo Engineers in Phoenix, Arizona, in 1933, we have had a strong presence in the southwest region. In addition to working from our company headquarters in Phoenix and main offices in Walnut Creek and Orange County, we have expanded to nine other offices in the region, which enhances our services to local clients. The southwest region has over 300 registered civil, environmental, electrical, instrumentation, mechanical, chemical, and structural engineers, as well as architects, planners, and other specialists that can guide a project from conception to fruition. Our projects range from the design of very small systems to plants treating hundreds of millions of gallons of water or wastewater daily. We have long-standing relationships with many local clients including Eastern Municipal Water District, Orange County Sanitation District, East Bay Municipal Utilities District, Metropolitan Water District, Clark County Water Reclamation District, and the City of Phoenix. Our areas of expertise include water and wastewater treatment, master planning, hydraulic modeling, infrastructure design, asset management, and construction services.