Composting toilets require no water to manage raw sewage, toilet paper and food wastes. Their minimal use of water for flushing significantly reduces municipal water use, while also reducing the volume of the residual sludge. They make use of unsaturated aerobic conditions, facilitating biological and physical decomposition of the material by bacteria and fungi. The end product is a soil-like dry material which has been reduced in volume by 10-30% through the decomposition process. These toilets have long been used in remote areas that do not have access to municipal wastewater conveyance systems, but they are also highly beneficial in urban areas as a water conservation and waste reduction measure. Some minor routine maintenance tasks are usually recommended to keep the toilet odour-free, and on a more long term basis, the sewage end product must be removed and hauled away by trained professionals.

For more information on this technology, download the United States Environmental Protection Agency’s Water Efficiency Technology: Composting Toilets fact sheet