Probably one of the most important questions addressed by Permaculture is not the one about where things come from (food from our garden, water from the rain, energy from the sun, wind, etc.) but where they go once we are done with them. Since the mere idea of trash (junk, garbage, rubbish, refuse, waste) contradicts everything Permaculture is about, a completely different approach is called for. Referring to the same things as scrap, raw resource, or compost, is a good start. In this way we start seeing the same things as solutions rather than problems.
When it comes to human excrement, it might take a bit of an effort to view it as a rich source of nutrients, which almost sounds like food, rather than the pile of shit which it really is. Clearly, in its original state it is nothing more than a nasty, smelly, bacteria ridden problem, and a potential source of further problems, if not taken care of properly. For this reason I decided to take a look at a couple of solutions I have encountered on various Permaculture sites.
The Composting Toilet:
For most people, the first thing that comes to mind as a sustainable treatment of the end product of our digestion, is the classical composting toilet. In its most basic form, it is not much different from your old-times long-drop outhouse, with a few modifications. Instead of just one chamber, there are two, side by side. While one is being filled, the other one has time to turn the fresh crap into compost. After depositing a load, it has to be covered with some carbon (wood-chips, sawdust, bark etc.) When both chambers are about full, the older one can be emptied through the door built conveniently on the bottom side on the back of the chamber. From then on the empty chamber gets used while the other one is being composted. Depending on the size of the chambers and the frequency of usage, this must be done on a monthly to a yearly basis. Note though, that the deeper the chamber is, the more difficult it is to cover a deposit entirely with sawdust. If there is even a small area exposed, it will attract flies and other insects, and repel anyone who is not so fond of the smell.
The clear advantage of this system is the abundance of good compost it provides on a regular basis. On the downside, regular labor associated with mining this great resource is programmed into the equation. Also, some people might not be too comfortable seeing (or sometimes feeling) all the life that is part of turning the waste of our bodies into food for our plants. On the other hand, I must note all the amazing views I have had while sitting on various composting toilets: lakes, forests, mountains, canyons, and volcanoes, depending on the place. Maybe these two sides go together, and it's in fact a clever Permaculture design that uses the most majestic views of nature to distract from all the action "down there".
Another important point is the issue of the urine separation. It is not advantageous for the composting toilet to get drenched with urine on a regular basis. For this reason, people are advised to take care of their "small businesses" in the bushes. This sounds fairly uncomplicated, at least for me, being a male who has generally little problems with just turning away from people while watering the trees. Nevertheless, I must admit, that even I have felt it annoying having to refrain from emptying my bladder while relaxing my bowels. Because I'm probably not the only one, more advanced composting toilets have installed a urine separator. That is a little pan placed in the front of the hole to catch the urine and funnel it away from the compost.
The Bucket Solution:
A simpler version of the composting toilet, and probably the one that requires the least infrastructure is the bucket. It's just as simple as it sounds: a five-gallon bucket with a toilet seat on it, and a bag of sawdust on the side. Because of its minimal size, it is inevitable that it must be emptied once a week at least. Initially, this might seem as a disadvantage. However, taking the bucket to the compost, dumping it out, covering it with some more carbon, and hosing out the bucket can all be done in a matter of ten minutes. And because of the small size of the bucket, it's fairly easy to ensure that everything is 100% covered. For this reason I have found this bucket solution to be cleaner, less smelly, and less frequented by insects than the classical composting toilets.
A compromise solution somewhere between the bucket and the composting toilet is the wheely-bin. It is a plastic garbage bin with two wheels, such as issued by many cities for trash collection, placed under the toilet hole. The fanciest variety I have encountered was indoors, just under the bathroom, with a urine separator pan, and a “bumwash” shower-hose right next to it. The size of the wheely-bin required it to be emptied out about once a month. The owner and designer emphasized this with a strong “ONLY,” which others might not find justified. Also, a faint smell in the bathroom could not be ignored, despite the generous amounts of sawdust used. As for me, I'd still prefer the bucket, especially if it's outside.
Using Water, the WC:
The English Water Closet, for many people the epitome of modern western hygiene, still features certain advantages that cannot be ignored: With one press of the button everything is flushed down the drain. Clean water filling a pipe forms a perfect seal over everything that's below, stopping even the faintest smell from coming through. (If there IS a smell, it must come from the bowl or the water itself.) These advantages of hygiene and convenience are hard to pass up, especially if one has been brought up with them as a kid.
But where does the water go, and all the stuff with it? Nobody knows, nobody cares. Or do they? Could it all go to a place where it can be used in some way? Could it be composted? In fact it can, and the solution is not even that complicated. One type of method is the worm-composter. The system I helped to build is intended for a small household of 1-3 people.
Firstly, the solids must be separated from the liquids. Worms love to eat our crap, and the castings they produce makes excellent compost for plants. But too much water would kill the worms, so we must catch the solids and let the water pass on through the system. For this we used a concrete basin of 180x60cm, and a depth of 70cm. In the bottom we laid a loop of drainage pipe meeting in a T-joint, leading out through the drainage hole of the basin. Then we covered the pipe with gravel. The water would flow through the gravel and the holes on the side of the pipe straight out of the basin and onwards through a closed pipe. On top of the layer of gravel we suspended a mesh basket. This is where the solids would remain, and where the worms would live.
The basin cover had two screw-top holes: one for the toilet pipe would go, the other to add various other organic matter, such as kitchen compost, for worm-food. The two could be switched, to keep all the shit from piling up on one side, although the worms eventually spread out everything evenly.
The backwater would then continue on to another basin of slightly smaller dimensions: 130x60cm and 70cm deep. This is the filtration tank, where the water would pass through a layer of bark and a layer of scoria, a sponge-like volcanic rock. Here the water would sit for a while, until displaced by the incoming flow of more black water, as well as the gray water from the shower, sink, washing machine, and kitchen sink (the two pipes leading into the main chamber through the lid). The exit hole on the side sits just on the line between the scoria and the bark, so the bark stays mostly dry except for the occasional soaking while the water passes through. Both the bark and the scoria have an extremely large surface area, where all types of microorganism will flourish, feeding on the grease, hair, skin particles, dust, dirt, and shit that comes with the water. The small chamber on the side is empty, so the water level can be seen. The red rock in the main chamber is the scoria (the bark hasn't been added at this point).
The next step after this tank is the 97-liter dosing chamber. This feature of the system ensures that when water enters the soakage trenche, it spreads out evenly. Without the dosing chamber the water would dribble little by little, every time the facilities are being used, without much pressure, and accumulate in the lowest section of the trench. However, if 97 liters are being flushed at once, the entire pipe fills up evenly. This type of dosing chamber works with a pressure siphon. The lack of moving parts guarantee the low maintenance aspect. More information on this and other dosing chambers can be found here: http://www.siphons.com/operation.html
Eventually the water drains down the hill into the pipe inside the trench. The trench is 30 meters long, following the contour line of the hill. The pipe is tied onto pegs, placed exactly at level, with a hole every meter, and an outside pipe over each hole to discourage roots from growing into it. Around the pipe the trench is filled with more scoria as well as charcoal. This will soak up the water as soon as it comes out of the pipe, and more microorganisms will further clean it.
The following picture shows the still uncovered pipe during a test flush. All holes squirt water at about the same pressure, indicating an evenly leveled pipe. The last picture shows the trench filled up with scoria.
About a meter further down the the hill a line of citrus trees make use of the water that passes onward through the trench. About fifty meters further, the water passes into a pond, once it has passed through the filter, the trench, and the orchard. A red aquatic weed grows on the surface, which can be skimmed off and used in the garden. It is very rich in nutrients and can be either dried, used as mulch, or mixed into the soil. In any case, it returns the excess nutrients back into the food circle, allowing us to eat our shit in form of healthy, tasty, nutritious food.
This solution is by no means the only one. Each setting, each situation has its own set of circumstances, which will demand its own solution. This example is just to illustrate that there is no need to compromise ecological responsibility for hygienic convenience, or vice versa. There is ample room for both, and much more, if only applied creatively, giving everything its due consideration.
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