The Dirt on Composting Outhouses

Photo Credit: Christoph Dietzfelbinger

The Dirt on Composting Outhouses

👤Christoph Dietzfelbinger 🕔Mar 30, 2016

Every rural dwelling should have an outhouse. Outhouses rarely plug up, their pipes don’t freeze, they operate without a water supply and they remind their users that there is no mysterious sink into which unpleasant and unwanted things disappear. They allow us to step outside to a different place and to look at our houses and lives from another point of view—literally.

Outhouses are also great savers of drinking water. Even low-flush toilets make a nasty, stinky excrement soup out of six litres of perfectly good water every time you push that button, while conventional toilets can use more than twice that. If you’ve built a conventional system, you know how expensive pipes, septic tanks and lagoons are, and how easily they malfunction.

Outhouses need not be smelly, dark places where one trembles to plant a buttock. They can be friendly, pleasant places. Like mine, which I will proudly introduce to you here.

Overseas inspiration

When I built the remote Burnie Glacier Chalet in the Howson Range southwest of Smithers in 2001, I had to address sanitation in a place far from city sewers and flush toilets. I remembered how much money and effort the alpine clubs in Europe were putting into the sanitation of their huts.

A mountain hut in the Alps is not what we are used to in Canada. Some house 200 people and accommodating 80 guests is not a large operation. There are many of them, and their summer and winter seasons are long. All those people make a lot of excrement, and it has to go somewhere. Conventional sewer systems are challenging and expensive to build in cold areas with no soil at the heads of large watersheds.

I remember some hardcore biffies like the one at the 3,700-metre-high Bivacco Ghiglione in Mont Blanc: the drop through the metal floor down to the glacier was substantial, and updrafts would return used papers to the sender. Those things became unacceptable around the time I left in the mid 80s.

In 2001 British Columbia, a pit toilet would have been permitted, but I wanted to keep human waste out of the water table. So we built a composting outhouse, which has served beautifully for 15 years. I’m grateful for its work. Imagine absorbing fully 1,000 dumps in one winter and digesting it all in the summer! Yet it does, year after year, without any input of power or water. Well, I have to knock down the poopsicles once a week with a breaking bar, but that’s no big deal.

It rolls downhill…

Here’s the beauty of composting outhouses: instead of making up to 20 litres of nasty sewage out of the modest 0.25 litres of your average dump, they basically make the dump go away. Feces lose about 90 percent of their volume in the composting process. All it needs is time and space. The more the better.

It works very simply: build the outhouse on a 30-degree slope. Make the bottom impermeable; concrete works really well, but other materials do, too. Make the slope between three and five metres long and place the throne on top. Build a well-secured hatch into the bottom front, and let the relief begin.

The feces, together with paper and a bulking agent like sawdust, peat or leaves, glaciate slowly down that slope and decompose on the way. Vent the compost chamber so there is a slight draft down the hole, and the place does not even smell bad. Shovel out what remains once a year for heavy-use sites and every few years where it’s less. Use the compost in your garden. No pathogens survive several months outside the human body, and the organisms that break the compost down take care of any survivors.

The Y Factor

I know: there is the yuck factor. In North America, feces just aren’t cool. We’d rather dump them, more or less treated, into rivers and oceans. But feces and urine contain, among other good stuff, potassium and phosphorus, both non-renewable resources that are vital in industrial agriculture. Night soil was—and still is—collected, sold and used as fertilizer in many areas of the world. It is problematic if it is not composted properly, but once that has happened, it can go right back into the soil.

This is the basic concept. You can go a lot further with a urine-separating toilet, which allows the waste to be treated independently. By keeping the compost drier, it decays better and smells less, and flies find it less attractive to breed in.

Separett is a Swedish company that sells urine-separating toilet seats. They come with a cushy Styrofoam seat that is comfortable at below-freezing temperatures. Even the ladies in my household like it. The seat requires some plumbing: The urine hose needs to be plumbed into a pipe that takes the fluid to a bucket if you want to use it as fertilizer (a great way to use that potassium and phosphorus) or a greywater rock pit if you don’t.

In many countries, composting toilets are promoted by government and other agencies to increase sanitation and make the compost available for agriculture. This is a low-tech, economical approach that is documented in fascinating films on YouTube. According to videos, outhouses in India improve women’s safety and health because people don’t have to go into the fields alone to defecate, and the fertilizer decreases dependency on imported and expensive chemicals.

My next project, for which I left a hole in the floor at home, is the Indian-manufactured triple squat pan. I haven’t bought one yet because the minimum number is 500. While I consider going into business as a shithouse consultant once I can’t mountain guide anymore, that number seems a bit optimistic. The unit separates urine and is plumbed for washing in the back. Yes, many millions of people do not wipe. They wash.

My latest project, an outhouse I built at home before attempting to reproduce it in the backcountry, I finished just before the ladies got back from a trip. They approved, calling it nicer than they had expected. A few days later, the indoor toilet was plugged.