Photo: Dr. Jean-Paul Rodrigue, 2025. Royal Caribbean Cruise Terminal, Galveston.
Cruise ships are subject to strict environmental regulations concerning the disposal of greywater (from sinks, showers, and kitchens) and blackwater (toilets). While graywater can be discharged into the high seas, blackwater requires treatment and proper disposal. In the above photo, wastewater is being collected into truck tanks during the rotation between two cruises. The wastewater will then be brought to a local water treatment facility.