Chapter 7: Water Cleanliness and Small Vessels

Marine Sanitation Devices

Since it is illegal to dump untreated waste into any inland waters, one will need to have a proper sanitation system if the boat has a toilet. Usually, a sanitation system includes a toilet, waste system or marine sanitation device and a holding tank. The marine sanitation system (MSD) must be certified by the U.S. Coast Guard.

Now to review the different types of MSDs.

Pump Out State Sign
  • Portable toilets collect waste in a holding tank without treating it. They are legal for all vessels.
  • Type I MSDs treat waste and discharge it overboard. They are legal for vessels under 65 feet.
  • Type II MSDs are a more powerful version of Type I MSD. They are legal for all vessels.
  • Type III MSDs collect waste in holding tanks. This waste is then removed at pump out stations. They are legal for all vessels.

If using a Type III MSD, one needs to use a pump-out station to clean the waste in the holding tank. Keep an eye out for pump-out station signs which can direct one to where the nearest station is. If a Type III MSD is in use, it's a good idea to locate the closest pump-out station before heading out on the water.

No Discharge Zone:

One may not dump untreated waste, anywhere, in the United States. But, in a No Discharge Zone, one is prohibited from discharging waste even if treated. A No Discharge Zone is an area of water which is environmentally sensitive. It could be a special aquatic habitat or even a drinking water intake facility.

Pump Out Station

So, even if using a Type I or Type II MSD to treat the waste, one may not dump it in these zones. Even if sewage is treated, it could still contaminate or compromise the cleanliness of these areas in significant ways. No Discharge Zones are very often bodies of water with no navigable connections to any other bodies of water.

One must secure Type I and Type II MSDs so no discharge occurs while boating in these zones.