Composting Toilets

The book Everyone Poops states an obvious fact, and so humanity has forever been forced to answer the question: what do I do with this shit? Literally. Throughout history, societies have come up with a range of strategies to dump what’s been dumped, from burying it in pits to simply letting it run in the streets. For those of us born into the affluent West within the past 250 years, however, there has been only one acceptable system: the flush toilet.

Forget What’s Your Poo Telling You? (does it float? Gassy stomach), the flush toilet took a giant pair of shears to the connection between ourselves and our waste. Simply make a deposit, and a magical current of sparkling, drinking quality water will whisk all evidence away, to a never-never land, the great sewer in the sky. The flush toilet officially makes your poop Not Your Problem.

Certainly there are health and hygiene benefits to be found in separating human populations from mountains of fecal matter. But the system we have become dependent on to solve this issue was never going to be sustainable. Its basis lies in taking clean potable water, polluting it, then using more energy to clean it from the waste we added.

According to U.N. water statistics, conventional flush toilets in middle-class households account for approximately 30 percent of global water use.

According to U.N. water statistics, conventional flush toilets in middle-class households account for approximately 30 percent of global water use.

Or worse, the sludge is dumped into in a river or ocean where a normally very beneficial and nutrient rich mix creates havoc on the water ecosystem.

The flush toilet was thus perhaps the most harmful, least beneficial and yet most celebrated invention to ever be celebrated as a success of “development.” These seemingly luxurious seats of porcelain take a helpful, nutrient-filled substance and turn it into waste, while dirtying clean drinking water. The traditional toilet where it’s mixed with fresh water and thrown away just doesn’t make ecological sense.

There is evidence of water-powered sanitation systems even in archeological sites dating from the 31st century BCE, in Britain’s Skara Brae, Orkney, but it wasn’t until the 1850s that our familiar, clean water-intensive toilets became widespread. Since then, people have polluted an obscene amount of drinking water by using it as transportation for their waste, not to mention using energy and polluting through our bathrooms. Americans alone flush 4.8 billion gallons of water down their toilets every day. The waste from water toilets accounts for 90% of each household’s environmental pollution, and toilets account for about a quarter of the average home’s water use.

Skara Brae house site, Orkney Islands. There is evidence that water was piped under the settlement, possibly for sanitation.

Skara Brae house site, Orkney Islands. There is evidence that water was piped under the settlement, possibly for sanitation.

Luckily, after only a few generations, people are beginning to realize what an error we’ve made, and are designing toilets that combine ancient understandings of human waste’s potential with current sanitation technology.

Enter: the composting toilet.

A composting toilet is a dry toilet that uses a predominantly aerobic processing system that treats excreta, typically with no water or small volumes of flush water, via composting or managed aerobic decomposition.

By installing a composting toilet, you can transform your waste from environmental problem to solution. These toilets eliminate the use of water, instead transforming waste into compost through aerobic decomposition. The benefits to you and the environment are enormous. A compost toilet will provide you with a constant source of quality soil, save you money (installing a compost toilet costs 25-75% less than a septic system), and spare waterways the harmful runoff from common sewage systems.

After the initial time to get over any lingering squeamishness you might have after a lifetime of seeing your waste magically sail away, the transition to a composting toilet doesn’t have to be difficult at all.

There are two main types of composting toilets: self-contained appliance toilets, which compost waste directly under the toilet seat within the room, and central systems, also called remote or bi-level, which transport waste to a container located in another location. When preparing to make the switch, first consider what your space is like. Do you have enough for a bilevel? Do you have access to an adequate supply of energy, or will you need a passive design? Compost is catalyzed by heat, so consider whether you can put your toilet in a heated room or will have to heat and insulate your toilet separately? Consider locating your toilet next to a south-facing window or near a heat-generating machine to effortlessly increase its temperature.

Composting toilets appear similar to flush toilets. Their structures range from simple boxes to familiar ceramic seats, many of which have two chambers to guide the separation of urine from feces. After each use, all composting toilets require additional input of a cover material, such as ash, peat moss, or wood chippings. Bacteria and fungi then work their magic to alchemize human waste into humanure- a rich, humus soil, which is 10 to 30 percent of the original volume.

Composting toilets range from multi-thousand dollar high-tech machines to buckets with a toilet seat. Self-contained units allow waste to decompose right under the toilet, and must be emptied, while more complex remote systems funnel waste to a further location, perhaps a basement or backyard. Most pre-built composting toilets cost around $1,500 to $3000but pay for themselves in avoided water and sewage bills. Many high-tech toilets include special features to catalyze decomposition and prevent odor, including heating units, injected air, air baffles, and worm units. These add-ons will naturally require some energy input, however. A simpler model, built yourself, can be as cheap as the materials you can salvage.

Adding a composting toilet to a New York City residence is not easy. Eco Brooklyn has done it when we do gut renovations. We did it in a brownstone and in a shipping container building. The reasons for doing this in Brooklyn or NYC are primarily to reduce the flooding of the rivers with sewage when it rains.

In places outside of the city it makes even more sense. If you are in a place that uses ceptic systems then the reasons are even greater.

If you’re ready to take the plunge, you have a variety of options:

You can build your own.

Instal an Aquatron system to decompose your waste at a distance or in your basement.

Buy one of Envirolet’s dual-fanned toilets.

These are half the price of most models.

Sun Mar produces self-contained models if you don’t want a separate holding tank.

A less expensive, simple box design.

A high end firm that consults and installs their own designs.

A New York and Brooklyn Composting Toilet Installer: Eco Brooklyn. These gays are amazing.

One unfortunate hurdle to installing a composting toilet is that, as with any building project, you must apply for a permit, and since they are relatively unknown in the United States, composting toilets sometimes face ignorance-induced discrimination from the local department of building (DOB).

This happened to Eco Brooklyn when we applied for a permit to install a composting toilet with SunMar. The DOB denied us because of concerns that it might release too much carbon dioxide, despite the fact that composting toilets are vented like any other toilet. Bottom line, their response was not based on fact: they didn’t know how a composting toilet works so simply denied it. A bottle of sparkling water releases more carbon dioxide into a house than a composting toilet. And besides, who cares. Carbon dioxide is hardly dangerous to a home.

Once installed, a composting toilet requires slight maintenance. Frequent addition of carbon heavy organic material is the most frequent maintenance, but think of that cupful of sawdust as the equivalent to a flush. Composting toilets will only clog if you overload it at a pace more rapid than it can decompose, so you no longer have to worry about dragging out the old plunger. If it does start to smell, troubleshoot by adding more cover material. You can put anything you would put into a normal composting pile into your composting toilet.

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One comment on “Composting Toilets
  1. michael says:

    We have one on our boat. It is from – the owner manufactures them in Maine (with some parts from a guy in Brooklyn). They work great. There is no smell at all (they must have an outside vent).

    No complaints, and we finally have a boat that doesn’t smell like chemicals on top of crap.

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