All shipping has a problem not just Cruise Ships – What do ships do with the waste generated on board whilst at sea. The more people the bigger the problem! This will include sewage, grey water, food waste, sulphides from exhaust gases, bilge water, holds which need cleaning out?
”Some 30 million people board cruise ships every year. And while they might return to land with fond memories of umbrella drinks and shuffleboard, they leave a lot at sea. About a billion and a half gallons (5.7 billion liters) of sewage , in fact.”Quote from Friends of the Earth
The US Environmental Protection Agency estimates that single 3,000-person cruise ship pumps 150,000 gallons of sewage—about 10 backyard swimming pools’ worth—into the ocean per week. One vessel in an EPA study produced 74,000 gallons of sewage in a single day.
What can we do about it?
No ports have their own effluent or sewage treatment works. To off load food waste, grey water and sewage it requires a fleet of lorries to collect it and take it in land to be processed. This is costed as Hazardous waste plus distance travelled by the tankers
Flushing out the bilges or cleaning the sulphides out of open exhaust scrubbers is often done in port or the approaches into a port and dumped into the harbour or sea.
The opportunity to treat waste on board ship makes sense