Clivus Multrum uses the processes of nature to decompose feces and urine into stable, odorless end product. The composting process follows a natural biological process. It requires good ventilation and some humidity which is important for micro-organisms to do their work.

The process is aerobic and occurs at a wide range of ambient temperatures (even when the outside temperature is well below freezing) unlike anaerobic processes which generate methane gas (marsh gas) and which occur at a higher temperature, a process that does not take place in a Clivus Multrum installation.

In order to start the composting process a starter bed consisting of peat, wood shavings and soil, adding organisms important for the process, is put in place. Occasionally, as the installation is being used additional wood shavings or material rich in carbon is added to keep the compost porous which is important for the filtering of the liquid and the ventilation of the solid.

Note! Do not use shavings from pressure-creosoted wood, hard wood such as oak, or wood with turpentine like from fir trees. Also, do not use material such as newspaper, leaves or long grass forming a sticky substance. On the other hand, standard toilet paper is suitable.

The Compost

Most of the solid organic material is converted into carbon dioxide and water, and evaporates. After 5-10 years only a small amount of end product remains containing the kind of minerals you find in ordinary soil.

If the usage compared to the size of the tank is adequate, the compost can remain in the container for several decades.

The processed compost when removed from the tank can be used in gardens as soil.

The leachate

The liquid (mainly from the decomposition of urine) goes through an important biochemical change. It passes through the composting heap and through the starter bed to the sloping bottom of the tank. When it finally reaches the storage chamber it is transformed into a stable, odorless, saline solution. It is a balanced high-nitrogen liquid fertilizer suitable for grass, trees and flowers. The liquid should be mixed with water before use. The leachate is biologically stable and can be stored if necessary.


A flow of air is sucked down the toilet stool, through the compost chamber. The air flow is necessary to avoid foul odors in the bathroom, and to add oxygen to the composting process.


Pathogenic organisms in the feces and urine which if un-checked may cause disease are eliminated during the composting process by soil bacteria and other organisms.

The liquids go through a process of nitrification. The end result is a brownish fluid, pathogen free, and rich in ammonium nitrite and ammonium nitrate, with a faint smell of earth.

Over the years Clivus Multrum has analyzed samples from installations (Test Results). Customers may request samples from their Clivus Multrum installation to be analyzed.