Finding ways to lower your environmental impact can be difficult, since recycling alone is often not enough. Composting toilets are one of the latest ways that people can do so while also getting all the benefits of composting.
Composting toilets, also known as dry toilets, offer a low-hassle and environmentally friendly way to make compost out of waste, also known by the portmanteau “humanure.”
Keep reading to find out just what a composting toilet is and what you can expect from the advantages and disadvantages of using one.
What Is a Composting Toilet?
A composting toilet is exactly what the name implies: a toilet that composts solid waste and liquid waste. Composting toilets work just like regular toilets, but also create an oxygen-rich environment that’s perfect for composting solid and liquid waste. The environment this creates lets bacteria break down the waste in what’s known as an “aerobic composting” process.
In short, a composting toilet is one that uses biological waste in the composting process rather than traditional composting materials like wood chips, fruits, and vegetables. Composting toilets have been present in national parks and similar areas, but they’re increasing in popularity in rural areas and properties like an off-grid cabin or tiny houses, where traditional sewer systems may be impractical.
It’s not just off-grid homesteaders using dry toilets, though. They’re also common in sustainable properties, in which homeowners apply as many eco-friendly features as they can. Composting toilets have also been incorporated into music festivals, with the Glastonbury festival in the UK using them since 2014.
How does it work?
How this process works depends on the composting toilet system that you use. Generally speaking, though, human waste goes in as you’d expect, though liquid and solid waste are usually stored separately, and it’s subsequently stored in a composting chamber and mixed with wood chips or a similar substance, where the aerobic bacteria breaks it down in a natural process.
Many composting toilets look almost exactly like a standard toilet, but they’ll have a few additions to allow for the composting process. It’s also split into several components, with the standard toilet that everyone’s familiar with being the visible section. Below that is the collection unit, where the evaporation process takes place.
Then there’s the composting chamber, where liquid and solid waste are separated and—as the name suggests—the composting process takes place. There’s also the aeration unit, which speeds up the process by adding oxygen to the gases created during decomposition.
The main difference between composting toilets and traditional toilets is that a composting toilet comes with some additional chambers and tanks that allow for composting. And, obviously, a composting toilet requires more maintenance, particularly in the emptying of it.
The process of doing so is quite simple, though. Some toilets have a tank or tray that can simply be pulled out and emptied wherever the rest of the composting will take place. With other models, you will need to open the toilet and use tools like a shovel and wheelbarrow to remove the material from the toilet before emptying it elsewhere.
Benefits of a Composting Toilet
Composting toilets offer multiple benefits, most notably environmental friendliness. For consumers, they could also be a practical purchase for several reasons.
Simple to install
Traditional toilets need to be hooked up to water pipes for them to function. If there aren’t any pipes already installed, they need to be put down, which is a long and complicated process, nevermind the cost. Composting toilets, on the other hand, are self-contained and don’t need any of this time or labor. While some options can be difficult to install, many can simply be placed in a room, and you can start using them.
More affordable than traditional toilets
Composting toilets are also more affordable than traditional plumbing and toilets. The cost of a home with indoor plumbing and water hookups can’t compare to the low one-time cost of a composting toilet. A composting toilet can cost as little as $50 if you build it yourself or as much as $1400 if you buy a top-of-the-line model. Even $1400 doesn’t seem like a lot of money when you consider what a homeowner spends on construction, plumbing, and water costs over the lifespan of a home.
Preserve water
Compost toilets don’t need water to function. That makes them exceptionally suitable for people in drought-prone areas, as well as those who want to reduce their overall water consumption. Since toilet flushing makes up nearly 30% of the average household’s water usage, switching to waterless toilets reduces water usage considerably.
Composting toilets provide free compost
Composting toilets take the effort out of free compost. You can just sit back (literally) and let your composting toilet work. Once your human waste has been safely converted into compost, it can be put to multiple uses, such as improving your garden. You can fertilize your soil and flower beds easily, making it an appropriate alternative to fertilizers for eco-conscious homes.
Disadvantages of a Composting Toilet
While composting toilets offer multiple benefits, they also have their drawbacks.
Odor
One of the more notable may be one of the most obvious. Since you’re composting human waste, there’ll naturally be a smell involved. While most composting toilets come with odor removal technology, not all of them do, so you may need to be prepared for your toilet to smell a little worse.
Maintenance
Then there’s the maintenance involved in the process. Since the aerobic decomposition process takes time, you’ll be adding more and more waste to it every day, so there’ll be a mix of old and fresh waste, which will all be in various states of decomposition. That inconsistency means you’ll need to spend more time mixing the waste and making sure there isn’t any excess liquid. The tank capacity plays into this, with many toilets needing to be emptied every few weeks or sooner, depending on how much you use the toilet.
Regulations
Local regulations may interfere with your ability to install a composting toilet, especially if you’re getting off the water supply and sewage system. You’ll need approval to do so, which can vary in complexity depending on where you live. Local building codes may also dictate the types of toilet you can install, which may limit the composting options you can choose from. Furthermore, you should research local, state, and federal regulations and guidelines regarding the disposal of human waste, even as it applies to compost.
Types of Composting Toilets
As mentioned above, a composting toilet works in different ways, depending on the type of toilet you get. There are two main types of composting toilet to choose from, self-contained and split, both of which offer pros and cons, and both of which can come in either continuous or batch systems. While the overall composting process remains relatively similar, each option differs slightly.
It’s worth noting that most composting toilets don’t use hot composting as part of the process, instead dehydrating and decomposing the waste. The material needs to go through this process, however, as the heat generated during hot composting destroys any diseases or pathogens contained in the waste. As such, the material needs to be placed in a compost bin that encourages hot composting after it’s been removed from the toilet.
If you want to use a compost toilet without turning the waste into usable compost, you will have to arrange for the materials to be picked up and hauled away by an appropriate service provider.
Self-contained
A self-contained composting toilet is an all-in-one system that has the pedestal and container within the system. Self-contained composters are recommended for homes that are short on space, especially if there’s nowhere for a separate septic tank. In addition to use in small homes, these can be used instead of a septic system in boats, caravans, RVs, and motorhomes. These act as not only standard flush toilets, but also as the waste container, with the compost heap staying inside the tank.
They have the added benefit of using little or no water, even less than its alternative.
While you’ll need to clean out the organic matter occasionally, how often you need to depends on the size of your self-contained system. It’s worth considering this factor when choosing the size of your self-contained composting toilet, as larger ones will need you to collect waste and compost less often.
Split system
A split system composting toilet comes in two parts, namely the pedestal and the tank. The pedestal, which is located above the floor, effectively serves as your toilet seat and is where you do your business. The tank is located below the floor of the toilet and is where you flush waste, effectively serving as a septic tank where the organic materials break down. This type of composting loo is better for homes that have enough room under the floor, as they’re not the most compact composting toilet.
Continuous
Self-contained and split system toilets can be further broken down into continuous and batch systems. With a continuous composting toilet, the toilet waste goes in one end and the compost comes out the other end. Ventilation will be necessary for this for several reasons, the most notable of which is to aerate the compost.
Batch
Batch composting toilets, on the other hand, have a tank that needs to be emptied on a regular basis. With these, the entire composting process doesn’t complete before the tank needs to be emptied, so you’ll need a separate place for the material to finish breaking down before it’s usable compost.
For batch toilets to work efficiently, the bathroom’s temperature must be well regulated, and the toilet itself needs a vent pipe.
How to Empty a Composting Toilet
Composting toilets need to be emptied when they’re full. The exact frequency will depend on the size of your composting toilet and how often it’s used, but in general you should empty it every three or four days. The process is quite simple, though you’ll need to follow these steps:
- Make sure the detachable tank is capped so it doesn’t spill.
- Unplug the connected cords and take it outside.
- Remove the lid and cover it with a trash bag.
- Empty the contents into the bag and put the tank back.
The process should only take a few minutes. You should make sure that you wait at least eight hours since you last used your composting toilet to give it time to settle before you empty it out. You must be sure to store the materials safely as you either treat it with high temperatures to kill pathogens or wait for a removal service to take it away.
What to Consider Before Choosing a Compostable Toilet
Choosing between composting toilets can be difficult for first-timers, but it doesn’t need to be complicated. To narrow down your options, focus on the factors that are most important to you. The best composting toilets will offer a variety of attractive features.
Odor will be one of the more notable areas to focus on. While all options aim to minimize odor, some do so better than others, as they can come with a vent and fan to air out the toilet.
Whether or not it offers urine diversion is another consideration. Solid waste has less of an odor and is easier to dispose of, so when the tank fills, you wouldn’t have to deal with any slush-like compost. If the urine and solid waste are in the one tank, it’ll take longer to dry, or you’ll need heaters to speed up the process, which can make the toilet more expensive to buy and install.
How often the tank needs to be emptied can also be a concern. Larger tanks will obviously take longer to fill than smaller ones. The longer it takes to fill, the less often it’ll need to be emptied, which may make it worth picking up a larger tank.
Composting Toilet FAQs
Can I use toilet paper in a composting toilet?
Anyone familiar with RVs and camping toilets may know that special toilet paper must be used with them. With a composting toilet, though, you can use regular TP. In fact, it can help with the decomposition process, but it does fill up the tank faster.
Is recycling human waste risky?
It can be, but with proper knowledge and precautions, you can still use your humanure. Though using a compost toilet boasts environmental benefits, composting human waste poses risks, thanks to natural pathogens present in the human body. These aren’t destroyed during standard home composting, so the finished compost can’t be used for plants, crops, and vegetation, as the pathogens can be passed on through consumption, spreading disease.
There is a process to avoid this and make human waste compost usable for these areas. This process, called hot composting, uses extremely high temperatures that not only encourage composting, but destroy pathogens and diseases. Some commercial composting toilets come with this as standard, although homemade options will need to take this into account.
If you plan to use a composting toilet, you are responsible for researching the regulations regarding human waste and the ways to compost it or remove it safely. This fact sheet from the EPA can serve as a guide to you. This website from US Forest Services has information on proper removal if you cannot turn your waste into safe compost.
How should I dispose of the compost?
Once the waste has been turned into compost, you’ll need to follow a few precautions when you’re using it to prevent the spread of pathogens naturally present in human waste. In addition to following the manufacturer’s instructions, it’s essential that you follow protocol to make sure the compost is safe for use in soil.
A high-temperature curing stage is vital to making sure the compost can safely be applied. During this stage, nothing more is added to the compost pile and the remaining organic materials are broken down. You must leave the compost undisturbed in a compostable environment—such as in a compost bin—to let it break down.
What happens if I have diarrhea?
Diarrhea and similar conditions can make it difficult to empty your composting toilet while the moisture also causes more of a smell. You can still use composting toilets when you have diarrhea, but it’s worth adding bulking material to the toilet to thicken it up and dry it out. You can use coco fiber or similar materials for this, but avoid using peat moss even if recommended because it’s notoriously bad for the environment.
Do composting toilets need electricity?
While not all composting toilets need electricity, some do. These typically need the electricity to power the fans and air out the toilet. Fans not only aerate the materials and speed up the decomposition process, but also minimize the odor that comes out of the composting toilet.
Wrapping Up
Installing and using a composting toilet offers multiple benefits, both for homeowners themselves and the environment.
With recent advances in the design and availability of composting toilets, it’s becoming easier and easier to expand your eco-friendly lifestyle, even in the bathroom.