Course Outline

Pumpout Station sign
Signs like this one are posted at pump-out stations.

There are three types of MSDs.

  • Types I and II MSDs are usually found on large vessels. Waste is treated 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.

Vessels 65 feet or less in length may use a Type I, II, or III MSD. Vessels more than 65 feet in length must install a Type II or III MSD.

All installed devices must be USCG–certified.

Pump-out station
MSD Diagram
  • Unit 7 of 7
  • Topic 12 of 16
  • Page 2 of 6