DEC

The Department of Environmental Conservation is New York State's environmental agency, and several of its programs leave lot-level records that matter in property diligence: petroleum bulk storage registrations, spill reports and their closure status, the state's remediation and brownfield-cleanup programs, and wetlands and other resource permits. It also oversees the state environmental review law that the city's CEQR process implements.

The practical reading: where a lot or its neighbors have handled fuel or chemicals, DEC's records are where the evidence lives — tanks registered, spills reported, cleanups begun or closed. State records complement city ones, and an environmental screen that reads only city sources is reading half the file.