How Does a Composting Toilet work?

By Thornton Plumbing and Heating

Share This Post

Blog Highlights:

  • Composting toilets are not similar to portable toilets
  • These toilets can actually help you save water, and it can work during a drought, or while you are on the go
  • The composting toilet is ideal for those who have RVs, boats, cabins, or houses that are off the grid
  • Basic ones can cost around $600 while those that have multiple features can cost thousands
  • The more discrete and hassle-free they are, the more expensive they can be

A composting toilet is basically a great option that will allow people with tiny homes or homes that are off the grid to have a working toilet even if there is no plumbing around. Portable toilets can also help you save water, and if you can go past misconceptions, it can actually be quite useful.

Experts say that you should never compare composting toilets with portable toilets. This is because composting toilets are highly engineered and as a matter of fact, they can even be used in the home continuously.

Those who are interested in buying one is actually doing so simply because they know that this type of toilet can help them live in an eco-friendly manner, it can work even without readily available water, and it can help you save money from having to install a septic system.

The composting toilet

Basically, this toilet turns solid waste into compost by creating an environment that is rich in oxygen. This allows the bacteria to break down the waste effectively. There are two basic designs for the composting toilet:

The central or remote toilet – It is designed to allow the waste to go towards a central composter. This can be somewhere outside the house or in the basement. This type is ideal for large homes that have multiple toilets.

Self-contained toilets – it is designed with the composting system located inside the toilet. This is used commonly in RVs, boats and in mobile or tiny homes.

The experts say that when it comes to the two designs, it is the central composting toilet that can be used closely like a conventional toilet.

How do they work?

Moisture levels are very important in composting toilets, you need to have a carbon-nitrogen balance, and you should also consider having the right temperature that will allow aerobic bacteria to turn solid waste into compost.

The level of Moisture

If the toilet has too much moisture, aerobic bacteria, or bacteria that thrives on oxygen, will not be able to function properly. This is why the toilet should be able to make the waste moist, and not wet. This is why urine must be diverted to a separate container that can be emptied regularly.

You can also divert urine and liquid waste into a drain or a pit. There are even toilets that are designed to evaporate the liquid waste. Solid waste must also be dried through a ventilation system to help draw out the moisture. This can help decrease the weight and volume of the waste.

The balance between carbon and nitrogen

If the urine is diverted properly, you can avoid having a buildup of nitrogen. But to achieve balance, you will need to add materials that contain carbon. You can use sawdust, peat, or coconut fibers to do this.

The right temperature

Aerobic bacteria will need a temperature of around 60-100 degrees Fahrenheit in order to survive. This is why some manufacturers have added sensors, mixers, and temperature control systems into the composting toilets that they make.

Why should you consider getting a composting toilet?

If septic options are not viable

Using septic systems can be expensive, and it might not even be allowed in certain areas. If you plan to go off-grid, septic systems might not be a good option to take.

If plumbing is not available

Plumbing is not readily available in many areas. Composting toilets can be used for isolated cabins that have poor soil conditions, or in areas where a temporary toilet is needed for the workers.

If water is not readily available

When there is a drought, or when water is scarce in certain areas, the composting toilet can be of great use. Some droughts can last for half a year.

The composting toilet can also help you save water, and it can even be more sanitary than the typical toilets. It can be an important asset today now that we need to conserve fresh water. It can also help reduce downhill pollution.

The types of composting toilets

The Electric composting toilet

It uses electrical components such as an electrical fan, as well as a heating system that will help maintain the temperature of the toilet. The heating system can also be used to destroy pathogens found in the waste. These toilets will need to use an electric outlet, or batteries, or both. They can also use non-electrical sources such as a wind turbine.

Dry composting toilets

Also known as a waterless composting toilet, it is either completely dry, or it uses very little water to flush. They can even be made to resemble conventional toilets.

Solar composting toilets

It is basically an electric composting toilet that utilizes solar energy to recharge batteries. Another similar variant is one that is quite complex. A glass panel is placed on top of the drain pit, this allows sunlight to penetrate and keep the microbes at optimum temperatures.

Portable composting toilet

This type of toilet is ideal for RVs and boats. It is designed for a moving environment and this is typically what is made by DIY or makeshift toilet builders.

The cost of having a composting toilet

The average price is typically around $600 for a self-contained type. While advanced toilets with many features can cost thousands. Although in general, they can cost more than the conventional toilet, you need to know that there are a few things that can affect its cost.

Composting toilets are not readily available, this is why they can cost a lot. Another thing is that conventional toilets install to an existing plumbing system. And these septic systems can cost as much as $20,000 to install.

You should know that a composting toilet’s design can increase its cost. This is because ones that are designed to be more compact and be more hassle-free will most likely be also more expensive.

Do they smell?

These toilets do not actually smell for as long as it is given proper care and attention. This is, however, a factor that you should consider especially if you have a weak stomach. But you should also know that because they use aerobic bacteria, these microbes are able to get rid of the smell and produce odorless carbon monoxide as well as water vapor.

These toilets are also sealed unless you are going to use it. The ventilation will also work to get fresh air in and the gasses outside.

FAQs about composting toilets

How long will it take for the waste to turn into compost?

It actually depends on the toilet, but in general, the longer the waste composts, the better the results. Self-contained toilets will also need to be emptied out every two weeks, if you maintain the proper composting conditions, this should not be a problem. If you have a large one, it will need to be emptied a few times each year. You can also add accelerators to help speed up the composting process.

Where should my compost go?

You need to follow the state’s laws when disposing urine and composted waste. You should also refer to the manufacturer’s guidelines for its disposal. In most cases, it can be placed inside the garbage bag so that the owners will not have to see the compost. If you want to use it for plants, be sure to use it on non-edible ones. Although composting destroys pathogens, you might not want to risk it.

What about toilet paper?

You can use toilet paper for as long as it is 1 ply. You should not put feminine hygiene products inside it.

How is a composting toilet installed?

These toilets can actually be installed on your own, or you can ask a local handyman to do it for you. The most complicated part would have to be setting up the ventilation since it will require an intake line through the wall and an exhaust up the ceiling. This is why you might want to install the toilet at the right spot.

If you have a central system, then you should consider having a plumber, electrician or handyman install it properly for you.

What should I do with greywater?

Greywater is the wastewater that comes from the house with little biological material. To dispose of it, you can use a leach field to process and evaporate it.

Should I expect to do some maintenance?

Keep in mind that maintenance is very minimal, but they can make or break your composting toilet. For basic ones, you can add carbon material regularly, and make sure that you mix the compost. If you have an expensive one, the toilet might be able to do this automatically.

Units installed in cabins must be winterized. Depending on the model, you can choose to follow the manufacturer’s guidelines, unplug the unit, and shut off the water so you can store the toilet in a properly heated area.

More To Explore

We can HELP you solve your Plumbing, Radiant, Snowmelt, and Boiler Services

For a limited time only!

Get $75 off a New Water Heater

Let us install your water heater. Our licensed, insured pros can handle it.

Signup now to get our Water Heater Special our calendar is filling up fast. Feel free to call us if you have any questions 801-565-7948.