Actually, municipal sewage systems regularly dump millions of gallons of raw sewage after a heavy rain. The rains over flow the treatment ponds and they have to let the s**t out. It's typically more sewage from a
single municipal sewage dump than all the boats in the area could possibly dump in a century of bad Mexican
food.
No discharge rules are typical feel good legislation that a Politician can brag about but only hurts the boat owner's poscket book and nose but doesn't do diddly squat for the enviroment.
Type 1 sanitation devices exceed the typical municipal sewage treatment system for kiling the bad bugs. They do not do as good a job on the particulate matter, however. FWIW,
salt water kills most of the bugs in sewage in a couple of minutes. The necessity of treatment is problematical in saltwater for that reason. Freshwater is another story, however.