The Department of Environmental Protection (DEP) operates the largest municipal drinking water supply in the nation. Its mission is to protect public health and the environment by providing high quality drinking water, managing wastewater and stormwater, and reducing air, noise, and hazardous materials pollution.

Established in 1977, DEP is part of a long legacy of agencies that built critical infrastructure to improve living conditions for New Yorkers, beginning with the construction of the Croton Aqueduct in 1842.