How Does A Composting Toilet Work? Everything You Need To Know

Composting toilets are quickly gaining in popularity. It’s no longer just an option for campers but also for people with a mobile lifestyle. Even regular homes can install a compositing toilet. 

Composting Toilets – What’s the Lure? 

Traditional toilets already work, why then should people still consider composting toilets? The reason why some people are attracted to the benefits of a composting toilet is because the installation is faster and cheaper compared to your traditional toilet. 

If you are installing a septic system, it can set you back by up to $5000 depending on the difficulty of the set up and the location of your property. You also need to buy toilets, which can cost anywhere from $300 to $500 depending on the features and the materials used. With a composting toilet, installation and costs of the actual toilet is below $1000, making this a better option for cash-strapped individuals. 

Its impact to the environment and the property is also lesser compared to traditional toilets. The compost from these composting toilets should not be use as soil for gardening but they can aid in the growth of plants. That is also not to mention that flushing composting toilets does not require water compared to traditional toilets, even the water-efficient ones, that use gallons of water per flush. You can save as much as 7,000 gallons of water every year and that’s just for one person.

Installation is also more flexible. These composting toilets can be placed practically anywhere as they do not require in-house plumbing connection. This is why it is a great option for those who live in mobile homes or those who are living in remote areas. It doesn’t require water to be flushed down. You typically only need a formula of carbon additives, depending on the composting toilet’s manufacturer specifications. The carbon additives are what breaks down the organic wastes with the help of aerobic microorganisms. 

Parts of a Composting Toilet 

The toilet itself is composed of two parts: the part that you use for sitting and the part that is used for composting. The latter is composed of more parts such as the following: 

Storage Receptacle or Chamber 

Once the wastes are released from the body, it goes straight into the composting chamber or receptacle. This is where it will sit while it waits to be decomposed. This is where the unique design of the composting toilet works. The slope shape of the chamber allows it to separate the solid waste from the liquid ones. 


There is a unit that is in charge of eliminating gases. It also contributes to the degradation of the wastes in the chamber. 

Leachate Mechanism 

This mechanism helps get rid of the excess liquid that has gotten in the chamber. Excess liquid needs to be removed in order to allow bacterial activity to flourish. 

Access Door

An access door allows users to get the decomposed material easily. Once the decomposition process is done, you can open the access door and get the contents. 

How Decomposition Happens 

The human waste is predominantly made up of water. In fact, 90% of it is composed of water. However, this water content evaporates fast. And through the toilet’s vent system, that water can evaporate even faster. There are also some designs that allow external factors like the wind and the heat from the sun to evaporate the liquids in human waste. This is the case when it comes to passive composting latrine. 

In the event that external factors can’t be relied on, there are electric systems that work in heating up the waste, thereby causing the excess moisture to evaporate. 

However, for the composting process to happen, there should still be enough moisture in the wastes. There has to be a good balance between heat, oxygen, moisture and aerobic bacteria. This is when the decomposition process happens. The wastes will then turn into humus. 

How Does a Composting Toilet Work? 

Through the design of the composting toilet, the liquid waste is separated from the solid ones. The urine will go to the innermost part of the composting chamber where aerobic bacteria will convert it into nitrogen-rich liquid. 

The solid wastes, on the other hand also reach the composting chamber through gravity and undergoes the decomposition process explained earlier. In order to maintain good oxygen levels, aerating the compost is essential. This can be done with the help of a manual agitator. In some cases, composting toilets come with a rotating chamber. The chamber can be rotated in order to oxygenate its contents. 

Factors that Affect the Length of Decomposition Time 

So how long does the decomposition process work? There is no exact answer and this can depend on a number of factors such as the following: 

Number of People Using It 

The more people using the toilet, the slower the decomposition process will take. It might also require adjusting the four elements of decomposition in order to facilitate faster decomposition. Otherwise, it can cause anaerobic. You can tell there is not enough balance in the 4 elements if the toilet is reeking a bad smell.

The Capacity of the Toilet 

Composting toilets are not created equally. Some are designed to handle more wastes and others might not work quite as well when exposed to large volumes of wastes. 


Some toilets are designed for long-term decomposition. These toilets are better for people who don’t like to constantly monitor the condition of their toilet. These are also better for residential properties and mobile homes. However, for camping activities, you are better off with a short-term decomposition toilet. 

In general, it takes anywhere from 60 to 180 days to get a compost that is loaded with nutrients from a composting toilet. 


It’s important to know local regulations first when it comes to composting toilets. It’s not legal everywhere, so make sure you check out your locality to know the regulations when it comes to installing composting toilets. Once you are ready to buy one, check out our reviews. We also have a detailed guide on how to buy composting toilets. Read this guide and our reviews to make a better buying decision.

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