Only six states (Michigan, Missouri, New Hampshire, New Mexico, Rhode Island, and Wisconsin) have all, or nearly all, of their waters designated as No-Discharge Zones (NDZs). This means that not even treated sewage (like from a Lectra/San, a Type I MSD) can be dumped into those waters, but NDZs exist in only certain portions of other states.

Outside of NDZs, Type I MSDs can dump their treated waste into the waters legally and safely.

NDZs in the Southern states are:

Alabama: None.

Florida: State waters within the Florida Keys National Marine Sanctuary, Destin Harbor, City of Key West waters.

Georgia: Hartwell Lake.

Louisiana: None

Mississippi: None.

North Carolina: Broad Creek

South Carolina: Hartwell Lake, Lake Keowee, Lake Murray, Lake Thurmond, and Lake Wylie.

Texas: 24 Freshwater bodies (no saltwater areas).

(Other restrictions exist for certain freshwater bodies with low water access. See the laws on the below Web site to review those.)

For a complete list of NDZs and information about them and marine sanitation devices, go to www.epa.gov/owow/oceans/regulatory/vessel_sewage/vsdnozone.html.

Untreated sewage cannot be dumped in any waters unless the vessel is three miles from shore along coastal waters, and off the coast of Florida in the Gulf, a vessel cannot dump unless it is nine miles offshore.

(For more information on Type I MSDs and how they work, go to Our Waterways section on the Southwinds Web site, www.southwindsmagazine.com.)