33 CFR 159.7 "Requirements for vessel operators" lists the acceptable means of "securing" the system:
(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.
(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 (holding tank) 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.
Macerator pumps that can be locked with a key didn't exist when this reg was created. However, they ARE another acceptable means of securing the system. Either the coastie who didn't accept it has an advanced case of Barney Fife syndrome or didn't get that memo.
It is also illegal in Great Lakes Canadian waters to have a porti-potti. They don't want the ability to be able to dump into the water or on land.
Although it's true that PORTABLE portapotties are illegal in Canadian waters, the "MSD" version that's designed to be permanently mounted and fitted for pumpout is considered legal. However the Canadians have always been pretty tolerant of US flagged vessels equipped with portable potties...I've never heard of a single US vessel being cited, or turned back at the border if on a trailer.
As for any requirement that all overboard sanitation plumbing be physically disconnected from any thru-hulls in the Great Lakes, that's only true on Lake Champlaine and only enforced on locally registered boats. In fact, I've never heard of a single "looper" who's ever even been inspected.
--Peggie