The Phoenix Composting Toilet has one to three shafts with tines for aeration. Compost is removed at the bottom.
For years, Clivus Multrum has been the de facto standard for composting toilets in North America. Clivus was introduced in North America from Sweden during the 1970s by Abby Rockefeller. Almost single-handedly, the Clivus established composting toilets as a viable alternative to conventional flush toilets. While Clivus remains an active player in the composting toilet field, the product’s dominance in the field could be threatened by the growing popularity of a challenger: the Phoenix Composting Toilet from Advanced Composting Systems of Whitefish, Montana.
Glenn Nelson founded Advanced Composting Systems in the mid-1980s. Prior to that he was a licensed manufacturer of Clivus toilets (one of two in the U.S.) and played a key role in improving the Clivus design.
Through working on the Clivus design, he gained a great deal of insight into the workings of composting toilets—then, with the Phoenix, he designed a very different product.
Composting toilets allow human wastes to be converted into nutrient-rich compost, which can be used to fertilize plants—though most experts recommend against fertilizing food crops with composted human waste. Composting toilets save a lot of water by eliminating the use of water for toilet flushing (or at least eliminating most of the water). This reduces extraction pressures on aquifers or surface waters and (with systems connected to municipal sewage treatment plants) reduces the energy and environmental costs of treating wastewater. Compared with standard on-site wastewater disposal systems (septic tank and leach field), a composting toilet reduces nutrient loading of the aquifer and lower-elevation surface waters fed by groundwater.