Here it is verbatim...The first set of acceptable methods pertain to treatment devices in ND waters...
(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) Closing the seacock and removing the handle;
(2) Padlocking the seacock in the closed position;
(3) Using a non-releasable wire-tie to hold the seacock in the closed position; or
(4) Locking the door to the space enclosing the toilets with a padlock or door handle key lock.
The next set of instructions pertain to holding tanks and overboard discharge pumps and plumbing. Note "each valve," pertains to both seacocks and y-valves.
(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) Closing each valve leading to an overboard discharge and removing the handle;
(2) Padlocking each valve leading to an overboard discharge in the closed position; or
(3) Using a non-releasable wire-tie to hold each valve leading to an overboard discharge in the closed position.
[CGH 95–028, 62 FR 51194, Sept. 30, 1997]