A cistern is a large tank that can be used to collect rainwater for use on lawns and in toilets and washing machines. Water reuse and recycling in residential, commercial and industrial applications can reduce water demand and wastewater flow. In places like Japan, Australia, and in parts of the United States, water reuse for toilet flushing and lawn and garden irrigation is becoming relatively commonplace. CMHC's Healthy House in Toronto uses both these ideas to provide clean water for all household and landscaping needs without using municipal services. Rain and snow collected from the roof provides all of the water supply.
Water is stored in an underground cistern and purified without the use of chemicals.
All wastewater, which would ordinarily drain into the municipal sewage system, is treated in the home in a system that duplicates the soil's natural filtration process. It is then recycled for use in toilets, showers, and the washing machine. Water is typically recycled up to five times, with a small amount being safely released into the soil each day. Microorganisms, oxygen, ultraviolet light and charcoal are used to treat wastewater flowing into the soil so that it is not harmful to the environment. In addition, the house features appliances, fixtures and devices that use less water.