Each week, an average cruise ship (3,000 passengers and crew) generates:
- 200,000 gallons of human sewage
- 1 million gallons of gray water (from sinks, galleys, showers, and laundries)
- 25,000 gallons of oily bilge water
- More than 130 gallons of hazardous waste
- Up to 11,550 gallons of sewage sludge
The U.S. Environmental Protection Agency estimates that a single cruise ship burning bunker fuel emits the same amount of soot as 1.06 million cars every day.
Eighteen-wheelers, dump trucks, and buses—including most school buses—emit 15 ppm of sulfur dioxide into the atmosphere while idling, whereas cruise ships emit 1000 ppm of sulfur dioxide at idle.
Eighteen-wheelers burn 1 gallon of diesel fuel per hour of idling. One large cruise ship burns 320 gallons of diesel fuel per hour of idling, just to produce electricity.