Composting toilet

Composting Toilets are toilets that use bacterial processes directly within the unit to reduce waste to a safe, environmentally friendly compost or fertilizer sometimes referred to as humanure.

Composting toilets are currently much more expensive and may require more maintenance than traditional water toilets. The upside is that they do not use any significant amount of water and they may produce fertilizer safe for small scale agricultural use.

There are several challenges facing anyone designing a composting toilet. The toilet must control odors. It must be a largely continuous process as it must be able to be used without significant interruption. It must heat the feces to the point that harmful bacteria and viruses are killed or kill the microbes in some other fashion.

Human feces are far more hazardous than that of animals because they contain bacteria associated with human disease. For this reason, human waste should not be used as fertilizer without special treatment. Such illegitimate use is termed night soil.

Some composting toilets use electricity, while others do not. Some electrical systems use fans to exhaust air and increase microbial activity. Other systems require the user to rotate a composting drum from time to time.

Some composting toilets are large with a significant space requirement in the room below the toilet. Others are not significantly larger than a traditional toilet.

All composting toilets need to be emptied, although some manufacturers claim as few as two to three times a year even with commercial use.

A related device, the incinerating toilet, uses natural gas or propane to reduce the waste material to ash in a process similar to a self cleaning oven.

The vast majority of people in the developed world find the idea of a composting toilet to be somehow dangerous or at least very strange. The vast majority of people in the developing world could not hope to afford a composting toilet. For this reason, they remain a niche market primarily sold for use in remote cabins, other places that traditional sewage treatment or septic systems are not practical, or where an overt display of environmentalism serves some need. Of course, water based toilets were originally viewed with the same type of suspicions when they replaced the chamber pot.

Many health departments will not approve composting toilets as an alternative to septic fields. A septic field may still be required for treatment of grey water even if a composting toilet is approved. Before making a significant investmentment, check with your local health department.

Ecologically, the use of electricity should be weighed against the use of water within the context of your situation. In arid areas, water is probably more valuable than electricity while in wet areas, the opposite may be the case.