the sewage symbol
the sewage symbol


On-board sewage management is not a fun thing to think about, but it is a necessary part of your boat's systems.

The main concern with sewage in our waterways is bacteria and nutrients.

Bacteria can make boating and swimming unsafe and can close waterways and shellfish beds. Excess nutrients can cause algal blooms. Fortunately there are a range of options for on-board sewage management including toilets, holding tanks and even onboard treatment devices. It is important to consider the size of your boat, the type of boating you do, the availability of pumpout stations and if you boat in any No Discharge Zones when selecting the option that is best for you.

There are several options for on-board sewage including:

  • Portapotty
  • Composting head
  • Installed toilet with marine sanitation device

If your boat has an installed toilet by law you must have a Marine Sanitation Device.

The Law

Sewage regulations are some of the most misunderstood boating laws. To be clear, it is ILLEGAL to discharge UNTREATED sewage on inland waters and within 3 miles of shore. To legally dispose of sewage boaters must either have an on-board treatment device (Type I or Type II MSD) or a holding tank (Type III MSD) to hold the waste and have it pumped out ashore. A No Discharge Zone (NDZ) further prohibits the discharge of treated boat sewage.

  • Within NDZ boundaries, vessel operators are required to retain their sewage discharges on-board for disposal at sea (beyond three miles from shore) or onshore at a pumpout facility.
  • Vessel sewage discharge is regulated under the Clean Water Act. States can have all or portions of their waters designated as a No Discharge Zone for vessel sewage to:
    • Protect aquatic habitats where adequate and reasonably available pumpout or dump station facilities are available for the safe and sanitary removal and treatment of sewage
    • Protect special aquatic habitats or species
    • Safeguard human health by protecting drinking water intake zones

It is vital to know the locations of any No Discharge Zones in the areas where you are boating. They will be clearly marked on NOAA charts. You can also visit the EPA's list of No Discharge Zones.

General Tips

  • When tied up to a dock, use onshore facilities. Encourage guests to take advantage of the onshore restrooms before you set out for a day trip.
  • Regularly maintain your MSD and the attached plumbing and install the best hose you can afford to reduce odors.
  • Don’t be afraid to talk about the issue. Talk to your friends and fellow boaters about how to pump out.
  • Obey the law – keep untreated sewage out of all coastal and inland waters.
  • Find out if you are boating in a No Discharge Zone do not discharge any sewage, treated or not, in a No Discharge Zone.