Most people don’t realize it, but it’s not washing dishes or taking a shower that consumes the most water during the day. It is actually the act of flushing a toilet. Older, less efficient toilets work by passing more than three gallons of water through the plumbing system with each flush. As water resources become scarcer, ways are being sought to reduce some of the water that is literally being ‘thrown away’.

One method that is gradually becoming more popular is using a waterless toilet or composting. These toilets are rare in cities and suburbs due to the difficulty in obtaining proper building permits, but they are more common in rural areas. Composting toilets turn human waste into compost, which can be used as fertilizer once it has been treated.

Waterless composting toilets (also known as biological toilets) are waterless systems that rely on the principles of microorganism composting to break down human waste, paper, and other materials.

In this type of system, the chambers or containers are installed below ground level. Additional organic matter, such as wood chips, paper, or grass clippings, is added to create an ideal composting environment. Microorganisms break down the collected material, and about three-quarters are converted into carbon dioxide and water vapor. The air drawn in through the stack removes these gases and helps the microorganisms with decomposition.

Waterless composting toilets do not treat wastewater from showers, sinks and washing machines, an additional system is required for its treatment. A waterless toilet can range in price from as low as $ 400 to nearly $ 3,000, depending on the type and features. Many models look like normal toilets and are available in a wide range of colors.

Until the use of waterless toilets becomes more commonplace, removing and replacing an older toilet with a more efficient one can save the average homeowner 4,000 gallons of water per year. If all old, inefficient toilets were replaced with a WaterSense-labeled toilet, nearly 640 billion gallons of water could be saved each year.

What is a WaterSense toilet? It is a toilet with an Environmental Protection Agency (EPA) label certifying that it uses 20 percent less water per flush than current federal standards. Typically, a WaterSense toilet uses 50 to 60 percent less water per flush than older models.

The water efficiency of a toilet depends on its age and type. Most toilets installed before 1992 are considered inefficient by current standards and typically use more than three gallons of water per flush. This means that a leaky, constantly running, or simply inefficient toilet is the biggest waste of water in a home, as toilets are by far the main source of water use in a home. In fact, flush toilets account for up to 40 percent of residential indoor water use.