First it’s Poop, Then it’s Plant Food: The Water and Energy Benefits of Composting Toilets

Using a composting toilet can save water, energy, and help protect river and lake habitats by limiting the quantity of fertilizers entering water systems.
Author: Travis Leipzig

Toilets are the leading source of indoor water consumption, using an astonishing 27% of household water. Older toilets consume between 3.5 and 7 gallons per flush, and leaky toilets can waste between 150 and 200 gallons of water per day. With toilets flushing and leaking away approximately 20% of the worlds drinking water, don’t you think it’s about time for a change?

One option to save water in the bathroom is to use an EPA certified WaterSense toilet which can use as little as 1 gallon per flush. The US EPA provides a couple eye-opening statistics:

If just 1 percent of American homes replaced an older toilet with a new WaterSense labeled toilet, the country would save more than 38 million kilowatt-hours of electricity—enough electricity to supply more than 43,000 households for one month.

If every American home with older, inefficient toilets replaced them with new WaterSense labeled toilets, we would save nearly 640 billion gallons of water per year, equal to more than two weeks of flow over Niagara Falls!

But wait! There is an even more environmentally friendly option! To entirely cut out water consumption from the toilet, as well as save significant amounts of energy, one should consider installing a composting toilet.

If using a WaterSense certified toilet can conserve this much water and energy, just think how much more water and energy can be saved by using waterless toilets. Despite what people think, a properly designed composting toilet can smell as fresh as a daisy. There are a handful of commercial composting toilets which can be purchased, for instance the Lovable Loo, or one can be easily constructed as inexpensively as about $25 simply using a 5 gallon bucket, a toilet seat, some sawdust and a compost heap.

Here is a funny little silent film demonstrating the simple process of construction your very own composting toilet.

Water savings from composting toilets are pretty obvious, they don’t use any water. On the other hand, the energy savings embedded in this system may not be as apparent. As water is not needed, “upstream” energy is not needed to pump water to reach your toilet and the “downstream” energy required to bring sewage and waste to treatment plants is avoided. Similarly, with an increased use of composting toilets, less sewage reaches waste treatment facilities, thus reducing the energy demands of treatment plants and potentially delaying the need to expand or build new treatment facilities.

By reusing our own waste as an organic compost, a perfect example of integrated resource recovery, we decrease demand for chemical fertilizers, saving energy in the production process. In addition, less use of inorganic nutrients cuts back on the amount of chemical contaminants entering our water systems through ground seepage and runoff. This can provide communities downstream with cleaner water, potentially save energy in drinking water treatment facilities and protect river and lake wildlife and recreation. An article by the Massachusetts Department of Environmental Protection explains the consequences of chemical fertilizers:

Fertilizer is a "growing" problem for lakes, rivers, and streams, especially if it's not used carefully. If you use too much fertilizer or apply it at the wrong time, it can easily wash off your lawn or garden into storm drains and then flow into lakes or streams. Just like in your garden, fertilizer in lakes and streams makes plants grow. In water bodies, extra fertilizer can mean extra algae and aquatic plant growth. Too much algae causes water quality problems and makes boating, fishing, and swimming unpleasant. As algae decay, it uses up oxygen in the water that fish and other wildlife need.

A great resource to find out all about the history, process of and benefits from composting and reusing organic human waste is the Humanure Handbook (PDF) Here you can learn how to construct and manage your own composting toilet and pluming system, control odor, maintain your compost heap, prepare waste for reuse in your garden, and state by state legality and regulations. Regulations are found in appendix 3 of the handbook, located on page 274 (this one’s a biggy, probably a good idea to look into this before going out and constructing your own system).

As you can see, waterless composting toilets are a great opportunity for everyone to contribute to saving water and energy and protecting the environment. Self sustainability and simple living are keys to living a free and fruitful life, and practicing integrated resource recovery methods such as composting human waste is an awesome step in the right direction. See for yourself how far your poo can go.

Us Too!

We're thinking about getting a toilet like this at our cabin. Once you get used to the sawdust, things are not so bad.

This is a great idea!

Poop can be lawn care fertilizers. However, people should be responsible enough to see to it that their sewers are separated from their water lines and if possible, a waterless toilet should be a standard in every home and not just in public places.

What about septic systems?

We have low flow toilets, well water and a septic system. Most of the water we use goes back into earth via our septic. I also use a Tumbling Compost Bin for my non-meat and non-dairy food scraps. Is a septic as good for water conservation as a composting toilet?

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