Hazen and Sawyer is an American engineering consulting firm that provides services in the areas of water, wastewater, and environmental engineering. The company was founded in 1951 and is headquartered in New York City. Hazen and Sawyer has worked on a number of high-profile projects, including the New York City Department of Environmental Protection's $1.6 billion Croton Water Treatment Plant and the $1.2 billion Catskill/Delaware Ultraviolet Disinfection Facility. The company has over 60 offices across the United States and employs over 1,400 people.