It’s important to my husband and me to make our small farm as sustainable as possible. Composting toilets are the perfect fit for sustainability because they don’t use water. We want our farm to project different values than those that allow the immense use of water by Ohio’s ethanol plants, big agriculture and fracking. In this article, I’ll discuss our two years’ experience with composting toilets.
Composting toilets save water: Older toilets use as much as five to seven gallons-per-flush (GPF) of water. Although newer toilets cannot use more than 1.6 GPF, and high-efficiency-toilets use 1.28 GPF, that’s still a lot of drinkable water going down the drain. Compost toilets use zero water because there is no flushing. I discuss below what happens to the waste.
Besides saving water, it’s convenient to install a toilet in a cabin, boat or RV without connecting it to a septic system. We did this in an RV to allow farm apprentices to have private housing a distance from our home.
Composting toilets are Sustainable: The problem associated with composting toilets is usually how to safely dispose of human waste. What has nature always done with animal waste? It composts it, of course. And that is what we do on our farm.
Being a former physician, I recognize the potential dangers of fecal contamination to human drinking water and food. Let’s examine how we can deal with this safely.
Urine does not contain bacteria. When it does, the person has a “urinary tract infection.” What is in urine is a lot of nitrogen in the form of urea. In “Nature’s Head” composting toilet (below), the urine is collected separately from solid waste. We therefore use this diluted urine to fertilize nitrogen-hungry plants like sweet corn.
On the other hand, solid waste is full of bacteria that allow our colons to digest and absorb food. When people eat wholesome food and are able to avoid antibiotics, these are healthy bacteria.
Our compost piles consist of manure and bedding from our farm animals. After a couple years of composting, these ingredients become the vibrant soil that supports our garden crops. Can you think of any reason not to add human waste to a compost pile? Solid waste may contain some pathogens if put directly on the garden. But when composted, this risk is eliminated. Therefore, at our farm, all solid products from the composting toilets go into the compost pile.
Nature’s Head Composting Toilet: This composting toilet, in the intern’s RV, has worked out well. We chose it because its 21.5-inch height and less than 19-inch base is the only one sized to fit in such a small space. Also, its price of $1,000 is less than other composting toilets.
This composting toilet is made in Ohio. They have been wonderful about answering our questions and there is an online video for installation. It does require an electrical source and an outside vent. It can use peat moss for solid waste rather than requiring us to buy a special medium. The small manual that is included is clear in telling both how to install and to use it.
This toilet collects urine separately from solid waste. The bottle for urine has a cap and carrying handle. We found it convenient to purchase an optional second bottle. The solid waste doesn’t need to be emptied until the storage base is ¾ full, which isn’t often for a single person. The Nature’s Head company even encourages you to wait before emptying because “The longer you wait the more pleasant the job will be,”— mainly because the wastes will decompose to look and smell like dirt. Of course, we farmers would call that compost!
Sun-Mar Excel Composting Toilet: This larger composting toilet was purchased to put in the original outhouse on our farm. I initially chose this brand because there was a non-electric option. But because the outhouse already had electricity, we bought the electric model to ensure there would be adequate air movement to make it pleasant for company. I use our solar panels to justify electrical use, but also put the toilet’s electricity on a timer so it automatically turns off at night. The advantage of this brand is its bigger size that makes it more comfortable for larger people and for those requiring higher seating.
This larger size can also be a detriment because it requires a minimum space of 45 inches by 22 inches. The price of $2,000 also puts it in the higher bracket of cost. I don’t like that it requires the company’s brand of “Compost Sure” instead of peat moss. As most other composting toilets, it does require a vent pipe, but it also requires a safety drain which exits from the bottom of an evaporation chamber. It is quite easy to collect the composted material from a drawer at the bottom.
Conclusion: I do realize that a five gallon bucket with some peat moss at the bottom and a toilet seat on top would have been a cheaper alternative to these composting toilets. However, people visiting seem to take well to using them and I am glad to “close the sustainability loop” with human waste on our homestead. I am also pleased when we can do our small part for the future by using less water now.
Mary Lou Shaw homesteads in Ohio. Her book, Growing Local Food,”is available through Mother Earth News books.