Compost Toilet

composting toilet

A compost toilet works in a fashion similar to a backyard compost bin, breaking down waste into a soil-like material. The system uses very little if any water as the materials cannot be full submersed for them to break down. Bacteria and fungi work to aerobically decompose the waste from the toilet. The end product is called humus; according to the EPA, the humus is supposed to either be buried or handled by a licensed hauler since it comes from human waste. You'll want to check with your local and state health regulations when considering this toilet.

Components of the System

There are several components to most compost toilets, with some variation based on the specific type. The toilet system might contain any of the following:

  • Toilet
  • Chamber or reactor where composting takes place
  • Exhaust system for removing odors and by-products of the decomposition process
  • Ventilation to provide oxygen for the aerobic decomposition process
  • Door for the removal of the product when it is finished

Purchase Composting Toilets

There are several different types of these toilets on the market. You may find one works better for your household than another.


Envirolet produces a large capacity toilet made of heavy duty polymers. These polymers do not retain odors, which can be a plus for frequently used bathrooms. They also offer a SmartFlush system that moves the waste to a holding tank hidden behind a wall or outside. This increase the capacity of the toilet and minimizes odors.


Biolet also offers a flush system of composting toilet. They have been producing composting toilets for more than 35 years, and their toilets come equipped with fans and heaters to help mix and decompose the waste faster.


Sun-Mar offers both self-contained and central composting toilets. They evaporate their liquid so thoroughly that frequently the end waste is only three percent of what was started, so the system can run for long periods of time without needing to be serviced or emptied.

Nature's Head

Nature's Head makes self-contained compositing toilets that can be installed anywhere, including on board boats, RVs and trucks. They install quickly, and have a visible holding tank so you can see at a glance if the system needs emptying or service.

Toilet Options

Several different types of compost toilets are on the market, so you should be familiar with the differences before making your final selection.

Self-Contained or Centralized

A self-contained compost toilet is one unit that is best suited for occasional use. The composting chamber is at the bottom of the toilet rather than a separate unit. This option is good for a cabin or building that isn't used on a daily basis. A centralized toilet connects to a separate composting reactor. This style is better able to handle everyday use in a home.

Batch Versus Continuous

A batch, or multi-chamber, toilet follows the same concept as a multi-bin yard composter. One reactor is used until it is full. A new reactor is then used while the first one cures. A continuous, or single chamber, has only one chamber. The finished product is removed from the bottom of the chamber as new waste is added to the top.


A compost toilet has many benefits for the average homeowner.

  • Installing a compost or waterless toilet significantly reduces your water consumption. This helps both your pocketbook and the environment.
  • These toilets usually have a suction air flow that helps reduce odors in the bathroom.
  • The waste is managed locally instead of being taken to a sewage treatment plant where it might end up in a waterway. Sewage treatment plants also use chemicals in the treatment process. Sending less waste to the sewage plant means fewer chemicals.
  • The waste breakdown process doesn't require electricity like sewage treatment plants.
  • You can also use the toilet to recycle food scraps and yard wastes that go in a normal compost bin.
  • The material goes back into the ground instead of in landfills, waterways or other undesirable locations.
  • The toilets are beneficial in areas where water supplies are limited since they don't need water to function.


There are some issues that are worth considering before switching to this style of toilet.

  • You can't just flush it and forget it with this system. You have to maintain the system and remove the finished product when it's done decomposing.
  • There is a health risk if you come into contact with human waste that isn't properly composted.
  • Excess water can throw off the process and must be drained.
  • While the decomposition process itself doesn't require electricity, the toilet might need an electrical source to operate.
  • If you choose a composting toilet system that is too small, it might not handle the job.

Rethink Your Toilet

A compost toilet is worth considering if you're looking for ways to increase the green factor of your home. Weigh your options and select the one that best fits your needs.

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Compost Toilet