33 CFR §159.7

1. (a)No person may operate any vessel equipped with installed toilet facilities unless it is equipped with:
   1. (1)An operable Type II or III device that has a label on it under § 159.16 or that is certified under § 159.12 or § 159.12a; or
   2. (2)An operable Type I device that has a label on it under § 159.16 or that is certified under § 159.12, if the vessel is 19.7 meters (65 feet) or less in length.
2. (b)When operating a vessel on a body of water where the discharge of treated or untreated sewage is prohibited by the Environmental Protection Agency under 40 CFR 140.3 or 140.4, the operator must secure each Type I or Type II device in a manner which prevents discharge of treated or untreated sewage. Acceptable methods of securing the device include—
   1. (1)Closing the seacock and removing the handle;
   2. (2)Padlocking the seacock in the closed position;
   3. (3)Using a non-releasable wire-tie to hold the seacock in the closed position; or
   4. (4)Locking the door to the space enclosing the toilets with a padlock or door handle key lock.
3. (c)When operating a vessel on a body of water where the discharge of untreated sewage is prohibited by the Environmental Protection Agency under 40 CFR 140.3, the operator must secure each Type III device in a manner which prevents discharge of sewage. Acceptable methods of securing the device include—
   1. (1)Closing each valve leading to an overboard discharge and removing the handle;
   2. (2)Padlocking each valve leading to an overboard discharge in the closed position; or
   3. (3)Using a non-releasable wire-tie to hold each valve leading to an overboard discharge in the closed position.