What is a No Discharge Zone (NDZ)?
Also known as NDZ, a No Discharge Zone (NDZ) is approved by the U.S. Environmental Protection Agency, which prohibits boats from discharging treated or untreated sewage into water bodies. In these waters, a Y valve has to be closed. Currently, there are three NDZs in Florida; Destin Harbor, the Florida Keys Marine Sanctuary, and the City of Key West.