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It's the Law

As a boater, it’s your legal responsibility to help protect the Massachusetts aquatic environment.

Discharge of Sewage and Waste

Massachusetts law states that it is unlawful to discharge raw sewage or other refuse into Massachusetts waters. If you have a recreational vessel with installed toilet facilities, it must have on board an operable marine sanitation device (MSD) that is self-contained and incapable of discharging directly into the water.

All installed MSDs must be U.S. Coast Guard–certified.

Marine Sanitation Device (MSD)

Types of MSDs

There are three types of MSDs.

Types I and II MSDs treat waste with special chemicals to kill bacteria before the waste is discharged. Types I and II MSDs with Y valves that would direct the waste overboard must be secured so that the valve cannot be opened. This can be done by placing a lock or non-reusable seal on the Y valve or by taking the handle off the Y valve.

Type III MSDs provide no treatment and are either holding tanks or portable toilets. Collected waste should be taken ashore and disposed of in a pump-out station or onshore toilet.

No Discharge Zones (NDZs) in Massachusetts

No discharge zones, or NDZs, are designated bodies of water where the discharge of all boat sewage, whether treated or not, is prohibited. All Massachusetts waters are designated as “no discharge zones” for vessel sewage. (Boaters should note that waters of the Commonwealth can extend beyond three miles from the shore areas of Massachusetts Bay, Cape Cod Bay, and Buzzards Bay. See NOAA Chart 13267 for the federal boundary of Massachusetts Bay.)

When traveling in NDZ waters, boaters with Type I or Type II MSDs must do one of the following.

  • Close the seacock, and remove the handle.
  • Fix the seacock in the closed position with a padlock or non-releasable wire tie.
  • Lock the door to the space enclosing the toilet with a padlock or door handle key lock.

When traveling in NDZ waters, a Type III MSD (holding tank) must be secured in one of the following ways.

  • Close each valve leading to an overboard discharge.
  • Padlock each valve in the closed position.
  • Use a non-releasable wire tie to hold each valve leading to an overboard discharge in the closed position.

All of these methods of securing MSDs while in NDZ waters are approved by the U.S. Coast Guard.

  • Boaters with Type III MSDs can use any of the pump-out facilities located throughout the state.
  • For the best service, boaters should call ahead to verify hours or to make an appointment for a pump-out. See

Please Pump Out

Boaters can help reduce water pollution by pumping out their sewage. Pump-out stations provide wet vacuums that draw sewage out of a boat’s holding tanks for proper disposal.

Pump-out stations allow boaters to comply with the Federal Clean Water Act, which prohibits the discharge of untreated sewage in coastal waters within three miles of shore.

  • With the assistance of federal funding, the number of pump-out stations (and pump-out boats) has increased significantly. Boaters have responded by using them, which already has improved coastal water quality.
  • Pump-out stations also are available throughout the Massachusetts No Discharge Zones.
  • Locations of NDZs and pump-out stations are subject to change. Please check online at or call 617-626-1200.

Use the pump-out stations to keep sewage out of our fishing and swimming areas.