NYC DOB is the Department of Buildings. The NYC DOB is the department that enforces New York City's building codes and zoning regulations, issues building permits, licenses, registers and disciplines certain construction trades, and responds to and inspects over 1,000,000 new and existing buildings.
NYC DEP is the Department of Environmental Protection. The NYC DEP is a governmental part of New York City that manages the city's water supply and works to reduce air, noise, and hazardous materials pollution.
DIFFERENCE BETWEEN DOB AND DEP DRAWINGS
Typically, the NYC DOB is going to review drawings for things such as mechanical, electrical, plumbing, sprinklers, and anything pertaining to the interior structure of the building. As previously stated, the NYC DEP is going to oversee drawings pertaining to backflow prevention devices on incoming domestic water, grease interceptors, and all new sanitary and storm drainage.
Specifically for backflow-prevention devices, the NYC DEP drawings have an entirely different set of requirements from the drawings filed with the NYC DOB. The DOB drawings merely indicate location of the device but do not provide the specific components, selections, sizes, and access requirements from the DEP.