Where Does Cruise Ship Toilet Waste Go?

By Anna Duncan

Cruise ships have been a popular vacation option for generations, but with the growth of the industry, many people are asking the question: where does cruise ship toilet waste go? The answer, it turns out, is much more complex than most people think.

Cruise ships produce large amounts of wastewater every day, including sewage and graywater from showers and sinks. This wastewater is treated onboard the ship before being released into the ocean. The wastewater treatment process on cruise ships is similar to what is used on land-based sewage treatment plants; however, there are some differences due to space constraints.

The first step in treating onboard wastewater involves screening out any solid material. This material is then sent to a landfill or incinerator on land.

Next, the wastewater is disinfected with chlorine or ultraviolet light to kill any bacteria or viruses in the water. The water is then passed through a series of filters to remove any remaining solids and reduce pollutants such as nitrogen and phosphorus.

Advanced Treatment Systems

In recent years, many cruise lines have begun investing in advanced treatment systems that are designed to reduce the amount of pollutants released into the ocean. These systems use biological processes such as aerobic digestion and filtration to break down organic matter and reduce levels of metals, nutrients, and other pollutants.

The treated water is then discharged into the ocean several miles away from shorelines. Most cruise lines adhere to strict environmental regulations when it comes to discharging their wastewater, but some destinations may require additional measures if local laws require higher standards.


In conclusion, it’s important to understand that cruise ship toilet waste does not just disappear into thin air; instead it goes through an extensive treatment process before being discharged back into the ocean. Advanced treatment systems are becoming more common on cruise ships in order to ensure that only clean water is released back into our oceans.