What is a waterless toilet?
Approximately 20% of the world’s potable water is used to simply flush toilets. On average, each person uses over 1200 gallons per year by flushing the toilet. When you think of it this way, a waterless toilet makes a lot of sense. However, the thought of a waterless toilet likely brings to mind the old fashioned outhouse. But the modern waterless toilet is actually a common household appliance that is both economical and environmentally friendly. Besides, if you are living off the grid, a waterless appliance makes a great toilet option.
A waterless toilet is simply a “dry sanitation” system that does not use water to treat or transport waste. If properly designed, they conserve water and provide on-site processing of human waste material. Therefore, a waterless toilet provides an environmentally friendly option to transporting waste to a distant location which increases the possibility of pollution.
Waterless toilets are often preferred in areas where water is scarce or the environment is more fragile. They are a practical option for camping, an RV, living in a small cabin, or even on a boat. They also provide a great off grid toilet option where connection to an infrastructure is not possible. The most common type of waterless toilet is the composting toilet.
How does a waterless toilet work?
A composting toilet is a self contained device in which the waste is mixed with some type of carbon based material. This material is typically peat moss, leaves, or saw dust. The resulting “compost” is turned into harmless fertilizer by aerobic action.
The waste material in a composting toilet decomposes in a way similar to your garden composter. The main difference of course is the material being composted. Waste entering the system is over 90% water. Solids and liquids are separated by evaporation via a vent system. The remaining waste is broken down by natural decomposition. Consequently, the key to efficient use is a proper balance between moisture, heat, oxygen, and organic material. This balance provides the proper environment for aerobic bacteria to transform the waste into fertilizer.
Several key factors are needed in a composting toilet system to promote proper function and ease of use:
-a vent system for evaporation and to help disperse odors
-suitable environment for producing compost: the right balance of moisture, heat, oxygen, and organic material
-finished compost must be safe to handle and easily disposable
Types of Waterless Toilet Systems/Composting Toilet Systems
There are numerous designs of waterless toilets. However, all of the different designs can be divided into three main types: continuous composting, batch composting, and self contained composting.
Continuous composting/waterless toilet
These composting toilets have one chamber. The waste remains in the receiving chamber until the composting process is complete. This container is permanently fixed under the toilet, typically in a space under the floor. The finished compost is removed and buried.
-under floor space
-air inlet and exhaust (may be driven by convection, fan, or solar)
-access hatch to remove the final product
-a means of removing excess liquid
-additional of organic material such as saw dust to aid the composting process
Batch composting/waterless toilet
Batch composting toilets use several containers that are rotated. The “active container” is under the toilet. When it is full, it is removed and replaced with an empty container. The full container is then allowed to continue composting. Due to this design, batch systems take up more room in the bathroom or underneath the house.
-must be heated
-bathroom must be maintained at the proper temperature
-must be vented
Self-contained waterless toilet
A self contained waterless toilet is a smaller version of the batch type toilet. They are a perfect solution in situations where the composting chamber cannot be installed underneath the floor. The “receiving” container is fixed directly underneath the toilet seat. When it is full, the seat is removed and a clean container is put into place. The full container is then allow to continue to compost. This takes 4 to 6 weeks. These are smaller systems and typically serve households with a maximum of 3 to 4 people.
-no under floor space is required
-must be vented
-must be heated
-no plumbing connection is required.
Important points to remember about a waterless toilet
-A carbon based material or bulking agent, such as leaves, peat moss, or saw dust must be frequently added to the container. This needs to be done daily or preferably after each use.
-A waterless toilet that is functioning properly will not smell
-Offensive odors usually means something is not working properly. Often just adding bulking agents takes care of this problem.
-Diverting urine from the main compost container helps to avoid excess moisture build up and can aid in the composting process.
-The system works more efficiently with the aid of a ventilation fan
-How often the “receiving” container is emptied depends on the size of the container and the number of persons in the household. When emptying the container, remember that the minimum “fallow” time or composting time is six months.
Choosing a waterless toilet system
The type of system you choose depends on several factors:
-number of people in the household
-frequency of use (continuous or occasional)
-size of your bathroom
-design of your dwelling. Is there under-the-floor space available?
-design approval by local regulations
-ability to build your own or purchase an off-the-shelf unit
Advantages of a waterless toilet
-Reduced water consumption
-Reduced need to waste water disposal
-Zero to minimal plumbing required
-More economical than a standard toilet/septic system
-In many cases, permits are not required
-Suitable for remote locations
-Adds organic waste to the environment
-Minimal environmental impact
Disadvantages of a waterless toilet
-Requires more maintenance than a traditional toilet system
-If not used or maintained properly, cleaning the toilet can be very unpleasant
-No every system adequately contains the odor
-Some systems are larger that standard toilets. Consequently, a waterless toilet does not always save space.
Safety Concerns with a Waterless Toilet
-Do not use the compost for cultivating vegetables
-Always use protective clothing when handling the end product
-If the toilet system is not working properly, active pathogens are still present in the compost.
Best Waterless Toilet Options
The off-the-shelf waterless toilets are some of the best on the market. Feel free to do your own research of course. But, I have listed the two most highly rated models on the market.
Nature’s Head: a self contained composting toilet HERE.
SunMar Excel waterless toilet HERE.
What about a homemade waterless toilet?
While the commercial composting toilets are great products, the price ranges from $500 to over $1800 USD. Most people that strive to live off grid also strive to live economically. Consequently, building your own waterless toilet is a great idea. However, be sure to check local regulations.
Building your own composting toilet brings up a lot of possibilities for various living situations. This skill is also great for potential survival situations. It also brings up the possibility of purchasing and living on cheap land or having a mortgage free tiny house. Not to mention that you will save on utility bills and reduce your impact on the environment.
A simple waterless toilet is made from a 5 gallon bucket with a toilet seat. For a great example, check out the Luggable Loo. HERE. The Luggable Loo is available from several different retailers for less than $20 and comes with a toilet seat. Place a couple of inches of saw dust in the bottom of the bucket. After each use, place a little more sawdust into the bucket. When it is full, the compost can be buried, emptied into your compost pile, or into a composting barrel. For long term composting, the best option is to empty the contents into a large compost bin.
Another option, which works very well, is to construct a small out building to house the toilet. Build a nice comfortable seat with a 5 gallon bucket underneath. Make sure the siting area is large enough to allow easy access to the bucket in order to add bulk material as needed or to rotate the buckets as needed. For this type of system, it is nice to have a built in urine diverter, which greatly reduces the liquid content in the bucket.
For additional resources on waterless toilets, and information on composting humanure, check out these resources:
The Humanure Handbook. by Joseph Jenkins
The Australian Government also has a nice guide to waterless toilets.
Other articles you may find interesting:Off Grid Shower Options