What Do Cruise Ships Do With Their Human Waste?

Cruise ships treat raw sewage, also known as black water, within a sewage plant in the engine rooms. It undergoes filtration, aeration, settlement, and sterilization before being treated in water treatment systems. Cruise ships are equipped with water treatment systems to clean human waste (black water) and grey water (water that goes down sinks and showers), and separate it according to its source.

Cruise ships dispose of waste sustainably, using a zero-landfill system, which allows them to deal with their own waste, from recycling to water. The kind of human sustenance discharged by cruise ships is not typically part of fish and other aquatic creatures’ diets, and introducing it can disturb complex food webs.

The U.S. allows cruise ships to dump treated waste into the ocean if they are within three and a half miles from shore. Beyond that point, there are no restrictions for dumping untreated, raw sewage in U.S. ocean waters. Cruise ships like Symphony have designated waste and recycling centers, with separate teams handling each incoming recyclable: glass, glass, metal, and more.

All forms of human waste must undergo an extremely rigorous treatment process within areas off-limits to all passengers. Cruise ship waste streams emit air pollutants to the air and water, and if not properly treated and disposed of, can be a significant issue. Cruise ships hide and eliminate unpleasant odors from human waste by using airtight holding tanks and specialized ventilation systems. Ships can dump treated sewage anywhere in the ocean except in Alaskan waters, where companies must comply with higher state standards.