How Do Cruise Ships Get Rid of Human Waste?

Have you ever wondered how cruise ships get rid of human waste? While it might not be the most pleasant topic, it certainly is an essential aspect of ensuring that all passengers have an enjoyable experience while at sea. 

To help you better understand one of the lesser-known areas of cruise ship engineering, we will provide a detailed explanation of how these massive ships store and dispose of human waste. We will also cover other essential topics, such as odor control and how cruise ships manage other types of waste on the water.

So, if you are ready to expand your knowledge of cruise ships, it’s time to get started!

How Do Cruise Ships Store Human Waste?

Before we get into the methods and procedures cruise ships use to get rid of human waste, it is useful to briefly explain how human waste is stored. While this may seem like a reasonably unimportant topic, if you pause to think about how unpleasant the smell and sight of human waste would be if not stored correctly, it makes you realize how important storage actually is.

The Separation of Various Forms of Waste Water

Human waste on a large cruise ship is separated according to its source. Where flushed toilet water needs specific treatment systems and storage facilities, less contaminated wastewater sources can be collected and stored in other ways. For example, wastewater from showers and sinks can be treated, filtered, and recycled to serve other purposes onboard the ship.

Storing Human Waste

Once the water is separated into the correct storage and processing areas, it must be held in the appropriate tanks. Water contaminated with human waste is stored in specialized, sealed tanks, known as black water storage tanks, or sewage holding tanks.

These tanks are designed to have completely airtight seals, which help with odor control. Human waste storage tanks are also located in areas of the cruise ship that are far from areas accessible to passengers.

Even though they are designed to be completely leak- and odor-proof, strategically positioning them within the ship’s off-limits areas reduces the risks of any accidents.

Regular maintenance and inspections are also performed to ensure that the waste water tanks are maintaining their airtight seals. 

How Do Cruise Ships Dispose of Human Waste?

Now that you know how human waste is separated from other forms of wastewater and how it is stored, we can explore the ethical and responsible ways cruise ships dispose of this unpleasant waste.

In the past, cruise ships and other large vessels simply waited until they were far at sea, then released their waste tanks. Naturally, this short-sighted and irresponsible attitude towards waste disposal damaged sea and ocean ecosystems. Thankfully, the cruise ships of today use more environmentally-friendly methods.

Onboard Waste Treatment and Disposal

Given their immense scale, modern-day cruise ships carry their own water treatment systems. These systems rely on a combination of physical filters, chemical treatments, and even biological processes that can break down and treat human waste. The wastewater treatment systems cruise ships separate solid waste from liquid waste, then they disinfect and treat the water.

Read Also: How Do Cruise Ships Get Fresh Water?

Once the water has been filtered and heavily treated to ensure it is sanitary and safe, it can be discharged into open water. This can only occur in certain areas where the impact on marine life and the ecosystem will be minimized.

The treated wastewater must also meet extremely strict environmental standards before it is released. Samples are taken regularly and randomly, ensuring that the water any cruise ship releases will not have a significant impact on marine ecosystems. 

All solid human waste is stored in an airtight holding tank after being treated, dehydrated, and removed from the wastewater. These tanks are not released into the water. Instead, they are held until the cruise ship is docked and in the harbor. From here, it can be disposed of safely and in accordance with local standards and regulations.

In Port Disposal of Human Waste

When a cruise ship is in port, waste disposal procedures differ greatly. This is because wastewater cannot be released into a port even if it is heavily treated. Instead, the wastewater is still filtered and treated the same way as it would be at sea; however, it goes through several extra steps, like being scanned and sampled to ensure it meets local regulations.

Once this has been completed, the heavily tested and treated wastewater can be discharged into the municipal sewage system, where it is treated at a standard water treatment facility per local standards.

Cruise lines must pay certain fees to dispose of their wastewater in port. Local authorities’ fees help to subsidize the costs associated with treating additional wastewater.

How Do Cruise Ships Dispose of Other Forms of Waste?

While proper storage and treatment of human waste is one of the most pressing concerns, cruise ships must also be capable of handling other forms of waste, especially at sea.

While cruise ships put a significant amount of effort into using recyclable materials, food waste and certain forms of packaging must be stored and treated properly. The same applies to hazardous materials, like medical by-products, cleaning chemicals, and more.

To handle solid waste, cruise ships segregate the material and dehydrate it. This helps with odor control. Onboard recycling programs salvage, sanitize, and repurpose items that do not need to be disposed of, as this helps cut down on the amount of waste that needs to be stored and helps reduce the ship’s environmental impact.

Once the waste is separated, treated, and stored appropriately, it can be disposed of properly once the ship visits a port equipped with the correct waste management facilities.

As you would expect, cruise ships take extra precautions when handling and disposing of hazardous materials. Everything is dealt with in the most efficient and eco-conscious ways possible.

Frequently Asked Questions (FAQs)

What is black water?

Black water is a term used to describe human wastewater within the maritime world, including by the cruise industry. Water that has come in contact with human feces, urine, or toilet paper is deemed black water.

Until treated, it cannot be discharged into the sea or ocean, as it could harm marine life and human beings living near coastal areas.

How do cruise ships hide odors from human waste?

Cruise ships hide and eliminate unpleasant odors from human waste by using airtight holding tanks. They also use specialized ventilation systems that make use of activated carbon filters.

To ensure that passengers and crew members do not detect smells relating to human waste, these storage tanks are also located as far away as possible from all personnel and passengers. 

Do cruise ships release human waste into the ocean?

Cruise ships are only permitted to release human wastewater that has been heavily treated. Solid waste is also treated and dehydrated but not released into any open body of water. Instead, it is disposed of through standard, onshore waste disposal methods once the cruise ship is in port.

Which chemicals do cruise ships use to treat human waste?

In addition to heavy filtration processes and settlement chambers, cruise ships use chlorine and a specialized combination of aerobic bacteria to break down and treat human waste.

Do you use previously treated wastewater when you are on a cruise ship?

No, none of the water that flows from the taps in your cabin is previously treated sewage wastewater. When you turn on your faucets or flush your toilet waste, you will always receive fresh water.

The wastewater that the cruise ship uses is heavily treated. It is either discharged into the water in designated areas of the ocean or released onshore into the local water treatment system.

Have any cruise ships ever leaked human waste unintentionally?

There have been some unfortunate incidents where cruise ships have accidentally discharged human waste or experienced unexpected leaks in their onboard waste treatment and holding facilities.

While these instances have occurred, they were all accidents, and the cruise lines were penalized according to strict regulations. This is done to limit the cruise industry’s environmental impact and protect passengers from exposure to unpleasant smells and bacteria.

Even when cruise ships dispose of other forms of waste illegally, they are heavily penalized. For example, read about how cruise ship garbage was illegally dumped in Cozumel, Mexico.

Final Words

Today’s cruise ships have advanced waste treatment facilities that use the latest technologies and protocols to manage and dispose of human waste. Ensuring that waste is disposed of in a way that protects passengers and the environment is the primary concern of all cruise ships.

We recommend reading about the cruise industry’s pursuit of carbon neutrality by 2050 to learn more about how cruise ships embrace environmentally-friendly technologies and methods. You can also read how Carnival invested over half a million dollars into a food waste biodigester. This unique and responsible attitude towards waste demonstrates how cruise lines prioritize sustainable waste management solutions.