What the ships do about the human waste?

Question

can they release it into the sea?

Answer 1

Depends on the ship's capabilities.    Just to be safe,  don't swim in the wake.

Answer 2

All ocean going vessels (registered in the U.S.) are required to have CHT (chemical holding tank) tanks in a size relative to the crew/passenger capacity. These tanks are emptied via pump hoses to shore facilities while docked and are allowed to be pumped at sea only beyond the 200 mile from shore line.

Answer 3

they have their own sewer plant  using osmoses.

Answer 4

They usually have a sewage tank to pump it into. Smaller boats pump it over the side.

Answer 5

All modern ships have to be fitted with a sewage treatment plant. This plant usually puts the human waste through several aeration procedures to break down the waste, and there are normally friendly bacteria in these tanks which actually eat the waste.

The resulting effluent goes into another chamber for chlorinating and then, if the ship is in deep sea, the resulting water, which is in fact quite clean, is discharged overboard.

Answer 6

They may pump it overboard depending on how far they are from shore. Inside that area they must keep it in a sewage tank. They normally pump this tank out at the pier. In the great lakes and navigable rivers there is no overboard pumping under any circumstances.