Which statement best reflects the sewage discharge guidelines for inland waters, 3 to 12 nautical miles, and beyond 12 nautical miles?

• A. Inland: 12 nm: No discharge; 3-12 nm: discharge permitted from comminuting; >12 nm: unrestricted discharge
• B. Inland: 3 nm: No discharge unless from an approved sewage treatment plant; 3-12 nm: Discharge permitted from sewage comminuting and disinfecting systems; >12 nm: Discharge permitted from holding tanks and spaces containing live animals, provided the ship is enroute at no less than 4 knots and doesn't produce visible floating solids
• C. Inland: 1 nm: No discharge; 3-12 nm: discharge allowed only from holding tanks; >12 nm: discharge allowed anywhere
• D. Inland: 3 nm: No discharge; 3-12 nm: no restrictions; >12 nm: no discharge

Answer: (B)

Sewage discharge is regulated by how close you are to land, with tighter rules near shore and looser rules farther offshore. Near inland waters, the priority is to prevent pollution, so ships must not discharge sewage unless it has been treated by an approved onboard system. That means you can’t just dump unless the sewage has gone through an approved treatment process.

In the 3 to 12 nautical mile zone, the rules allow discharge only when the sewage has been processed by a system that reduces solids and pathogens—specifically a sewage comminuting and disinfecting system. The help here is that grinding the solids and disinfecting the effluent lowers the environmental impact, making such discharge permissible within this band.

Beyond 12 nautical miles, the environment is more distant from land, so the rules permit discharge from holding tanks and spaces containing live animals, but only under certain conditions: the ship must be enroute at a speed of at least 4 knots, and there must be no visible floating solids. The combination of holding tanks and controlled conditions aims to balance operational practicality with protecting open-ocean waters from pollution.

So option that aligns with this structure—no discharge in inland waters unless treated, discharge from comminizing/disinfecting systems in the 3–12 nm band, and discharge from holding tanks (and spaces with live animals) beyond 12 nm under the specified conditions—is the best choice.