Why wet sanitation is washed up, while dry is high and dry

The Shitty State of Human Sanitation
(Part 1: The Problem, originally published in 2013 in http://www.chekhovskalashnikov.com/water-sanitation/ Estoy traduciéndolo al español.)

For Chekhovs Kalashnikovs very first interview on Change Makers, we will be talking with Chris Canaday, a biologist from California, about the broken and dangerous state of human and water sanitation systems and the solution to this problem that is damaging our environment and health.
 

I think that, before we talk about this revolutionary sanitation system, it is important to touch on why the current system is broken. Can you elaborate on how the contemporary western toilet came into being and the devastating effect that it has had on the environment and our health?

People in Europe used to live in total filth in their cities, throwing their excrement out the window. Porcelain flush toilets had been worked on for some time, but only in 1861, after her husband had died of fecally transmitted typhoid, Queen Victoria ordered flush toilets to be refined and installed in much of Britain.

It is also reported that she was so obese that she had trouble squatting and someone decided that it was not dignified for the queen to squat. They gave her a new porcelain throne and then, via mass psychology, all the Western World has wanted the same thing as the queen of England, even if it is not good for them or their environment.

The modern flush toilet has contributed greatly to the cleanliness of cities, but has not really solved the problem, just moved it farther away. Water always gets recycled and there are always more people living downstream. Developed countries spend millions and probably billions of dollars trying to clean up their wastewater, but never really succeed.

The modern flush toilet is largely based on the concept of “out of sight, out of mind”. It is also a prime example of selfishness: cleaning up the environment close to the user, while contaminating everyone’s general environment. 
It is interesting to note that at the same time that Water Closets were being developed, Earth Closets were, too. There was even one reportedly used in Buckingham Palace for a while. Over time, Water Closets won out as the standard for Modern Western Society, likely due to their ease of use and maintenance, as long as piped water comes to the house and sewage goes away.

Another key way in which the current, water-based sanitation system is “broken” is that it is based on the illogical, unsustainable and linear concept that natural resources should be used once and then thrown away. Flush toilets not only throw away huge amounts of water, but also all the nutrients found in the excrement.

With a simple push of a lever, we effectively deplete our agricultural soils and contribute to the eutrophication of rivers, lakes and oceans and, in them, the formation of hypoxic dead zones.

 If these nutrients were instead given back properly to the soil (and if the population were stable), we could forget about the non-renewable, unsustainable chemical fertilizers that are currently the basis of Modern Western Society’s food production. Those who learn to recycle these nutrients in an orderly way now will have every advantage in the future when these chemicals run out, and when there are possibly 9 billion people on Planet Earth, all wanting to eat.

Water is so essential and vital that we simply cannot live without it. Nonetheless, modern homes in developed countries dump between 25 and 40% of their water down the toilet, and the number engineers use in Ecuador is closer to 75%, given the high incidence of unmaintained toilets through which water flows constantly. We need to promote a culture of respect for water, as a source of life, which should never be treated as a garbage dump.

If these are not enough reasons to consider the current water-based toilet to be broken, obsolete and illogical, please consider the following unreliable, unhygienic and not-so-easy aspects of flush toilets:

• They often need to be scrubbed after each use, if they are going to be presentable.
• They frequently need to be flushed more than once for everything to go away.
• They occasionally get plugged and need to be cleared with a plunger, with sewage splashing or overflowing out.
• They make so much noise that everyone in the building can hear when they get flushed.
• The great turbulence of flushing creates a plume of microscopic, fecally contaminated water droplets that then land on everything in the bathroom, including the toothbrushes.

In the interest of full disclosure, flush toilets can be somewhat ecologically and socially sustainable in places where water is abundant, human settlement is dispersed, and the soil is absorbent, such that septic tanks (for settling out the solids) and leach lines (= drain fields; for allowing the contaminated water to absorb into the soil) can work properly, at more than 16 meters from wells or streams, and if the septic tank sludge is treated in reedbeds. 

Constructed wetlands are also important tools for treating wastewater, but they require a fair amount of land. On top of this, who knows how far all the different modern synthetic chemicals can travel in the water and the soil? So, in summary, it is most prudent to not mix our excrement in water from the beginning, especially if we have large numbers of people grouped together in a city.

So the reason Colon Cancer is skyrocketing in the Western World today is because we aren’t completely clearing our bowels, thanks to a custom-made invention for a morbidly obese queen?

Yes, and not just colon cancer, but also constipation and hemorrhoids. The natural position human beings have used when defecating, over millions of years, since before we were people, has always been squatting. In this position, the outlet is straight and the body can eliminate its waste more easily, efficiently and completely. When sitting, the outlet is not straight, certain muscles contradict each other, one needs to push more, and not all of the feces come out, so there is more constipation, hemorrhoids, and the colon never gets a rest from being in contact with festering feces, causing a greater incidence of colon cancer).

Squatting has the added advantage that it is more hygienic, especially with respect to women, since the user’s private parts do not touch anything. (Most women apparently never actually sit on a public toilet, but actually sort of hover above, which is much more uncomfortable than squatting all the way down.) Also, the squatting position is more accessible and intuitive for little children, since the floor is the same height for everyone, while a toilet bowl made for adults is much too big, uncomfortable and unsafe for them. Furthermore, in Urine-diverting Dry Toilets (UDDTs), the squatting position allows for a more certain separation of the urine and the feces, plus it is easier and cheaper to build.

In Ecuador, where does all the sanitation waste go? How much water is used and what effect does this have on the environment?





Almost all of Ecuadorian cities’ wastewater goes straight into rivers or bays, except for Cuenca, Shushufindi, and a few other cases where wastewater treatment is done.

The amount of water is huge and the excrement’s nutrients fertilize algae that end up dying and thus consuming the available oxygen in the water, creating the eutrophication and hypoxic zones mentioned above. But the biggest threat is that of pathogens in the water, which are responsible for the majority of disease in the world.

Many people have daily contact with rivers, for bathing, washing clothes or drinking, even only minutes after others have defecated in it, so it is obvious how disease can proliferate. Need more proof? Check out this:

Human Sanitation in Bumbay, India

I can just imagine the collective shit and piss from the hundreds of thousands of people living in Ecuadorian cities like Coca, Tena, and Puyo flowing into these Amazonian Rivers. What I find scary however is that this problem is not confined to Ecuador or even the South American Amazon but is worldwide.
What happens to communities that live on river banks, lakes, and areas prone to flooding with respect to worms, bacteria, and water-bourne diseases, like cholera that can be prevented with this system?

Yes, it is a discomforting thought, but the volume of shit is actually much greater if we remember that the millions of people who live in certain Andean cities in Ecuador, including Latacunga, Ambato, Riobamba, Cuenca, and Loja, also dump their waste into Amazonian rivers. Unfortunately, as you say, this situation is all too common in the world, where 90% of wastewater goes into the environment without proper treatment.

Even in countries like the United States, where things are presumably all under control, there are thousands of “sanitary accidents” every year, in which untreated sewage goes straight into the environment.

There are also numerous pharmaceuticals that cannot be removed from the water via conventional methods, such as antibiotics, antidepressives, and artificial hormones from birth control pills.

In addition, the current system of trying to kill the germs in the water with chemicals in one city, and the next downstream, and the next downstream, is a recipe for these germs to get resistant to these chemicals, especially if at the same time people are drinking and bathing in other peoples antibiotics. This has generated multiresistant strains of microbes that we cannot kill with chemicals to heal the people who get sick with them , nor can we be sure to disinfect a swimming pool even by adding chlorine.

In terms of health, the worst thing about flooding is that everyone is in everyone else’s shit.
This is an even bigger problem on the coast of Ecuador, where huge areas get flooded, with millions of people being affected, and it is getting worse with Global Climate Disruption. Urine-diverting Dry Toilets (UDDTs), on the other hand, can simply be built above the highest level of the flood waters.




One of the scariest results of all this fecal contamination, aside from diarrhea, typhoid, cholera, poliomyelitis, hepatitis, and other microbial diseases, is the high incidence of roundworms of the genus Ascaris, which infect about one-seventh of the world human population . There is a reason that the word for disgust in Spanish, “asco”, is so similar:

• These can be almost as thick as a pencil and up to 40 cm long.
• When babies are deparasitized, their diapers sometimes look like plates of noodles.
• Adult female roundworms produce 200,000 eggs per day and these can be viable in shaded, moist soil for years.
• The eggs do not just get swallowed and develop into adults in the intestines. Instead, they have intermediate stages that navigate in the host’s bloodstream, throughout the body. Eventually, they come out into the alveoli of the lungs, get coughed up and swallowed, and only then become adults.
• Roundworm infection is a big factor in many children doing poorly in school, since the worms consume so much of their food that little is left for the kids’ brains.

In Part 2 of this article Chris Canaday will tell us about the solution to human waste disposal and how it will solve much of the planets sustainability problems.
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The Shitty State of Human Sanitation
(Part 2: The Solution, originally published in 2013 at www.chekhovskalashnikov.com/human-waste-disposal/)

In Part 2 of this interview about human waste disposal and water sanitation Chris tells us the solution to all of the problems mentioned in Part 1: The Problem.

How did the new design for a sustainable human waste disposal system come into being?

In the 1950s, before the regrettable Vietnam War, a team of Vietnamese doctors analyzed why so many people were sick and how to control this. They found a great number of people were collecting “night soil” in buckets that were emptied in the morning directly in agricultural fields, where people worked largely barefoot.

The doctors realized that 90% of the fertilizer is in the urine that transmits no disease when dispersed in the soil, while essentially all the health risk is packaged with only 10% of the fertilizer in the feces. The answer was to keep the urine separate and set it free on the soil immediately, while jailing up the shit, until it is not shit any more.

In their case, they applied a detention time of three months, plus they added wood ash. This team that invented Urine-diverting Dry Toilets (UDDTs) was apparently anonymous, although it would be good for credit to go where credit is due, and to know more about the process.

UDDTs were later picked up by the Stockholm Environment Institute in Sweden, as a solution for the abundant cabins out in the Swedish woods, where running water is not feasible in the winter due to freezing, but they would never accept that their many beautiful lakes get contaminated.
They also actively promote these as a means to improve the health and sanitation of billions of people in the world.

I also suspect that certain ancient cultures had UDDTs, in particular the densely populated Amazonian peoples that made Terra Preta do Indio (Indian’s Black Soil, in Portuguese), until they were apparently decimated by Old World diseases soon after the arrival of Europeans.

No one knows yet exactly how they made these deep, dark, rich, long-lasting, productive soils, in the midst of extremely poor, highly weathered, clayey Amazonian lands, but I highly doubt that they were wasting the nutrients in their feces while they were doing so.

 ”Documentary: The Secret of El Dorado”

 
Can you explain how the design for this human waste disposal system works?

It is very simple and seeks to follow the natural order of things. The urine and feces that the body excretes separately are kept separate, to be dealt with separately, since they are totally different things.

The urine is caught in a funnel toward the front, since both men and women pee forward, and it goes back to the soil and the plants, where it transmits no diseases. (A bit of the urine from women may drip farther back, but this small amount is not a problem.)

Urine is normally sterile and there are only a handful of weird diseases that it ever transmits, plus for that to happen it has to go into rivers or contact the next person directly. The various microbes of urinary tract infections and vaginal infections either get destroyed rapidly in the soil or are natural inhabitants of the soil anyway. Many of these come from the gut, but here they are in much smaller numbers and are highly diluted, as compared to in the feces.

In addition, sexually transmitted diseases cannot live outside of the body any significant amount of time.


Feces drop farther back, directly into alternately used chambers or exchangeable receptacles and are covered immediately with dry cover material, such as soil, wood ash, sawdust, rice hulls, or a mix of these. They are then stored, protected from the rain, for at least six months in tropical countries or a year in temperate countries, so that all the disease organisms die and it all just becomes soil.

In fact, all the worst diseases, like cholera, diarrhea and typhoid, are wiped out in a much shorter time and the guideline of six months or a year is so that intestinal worm eggs, which are the most resistant pathogens but are much less life-threatening, are also eliminated. Most victims of these worms do not even know that they have them.

Shit is a temporary condition. After its jail sentence, it’s no longer shit: we open the chambers or receptacles and find dark, humus-rich soil, with no smell or health risk.
This stands to reason, since our pathogens are adapted to living in water without oxygen inside our guts, not in a pile of dry material, especially if there is soil in the pile, with all of its bacteria, fungus, protozoans and invertebrates.

These soil organisms are entirely at home in such a pile, where they eat and rip up anything that is over-abundant or out of place.

After this jail sentence, we can also apply secondary treatments involving heat, sun, earthworms or composting together with food scraps (especially thermophilic composting), for extra peace of mind or to speed things up.

We can build UDDTs for sitting or for squatting. In addition to all the health benefits mentioned above for squatting, this also allows for better separation of the urine and easier, less expensive construction.

Modern Western People tend to suffer from a psychological disease called fecophobia, which is an irrational fear of feces. Shit is a normal part of life and there is no disease in it that the user did not have from before, so, if the person is healthy, there is no health risk in his or her shit, only an unpleasant smell to be controlled and nutrients to be taken advantage of. If the user is sick, their pathogens get destroyed in the UDDT, as long as it is being managed properly.
There can be a health risk if, in a multi-family system, some of the users are sick and they are not using their UDDTs properly, such that some of their feces get mixed into the urine, but this can be controlled by storing the urine for a number of months (depending on the climate) or distributing it below the surface of the soil, where no one will have contact with it. The greatest health risk occurs when we do not think rationally about this and do the irrational act of throwing it in the river, where others can have contact immediately.

UDDTs are literally a matter of loving and trusting Mother Earth, in which we respectfully give back that which we no longer need, to let her deal with it. If we turn back the clock on shit, we find delicious food on the table. If we turn back the clock again (twice in the case of meat), we find beautiful plants growing in the sunlight. One more click and we see rich soil, so what is to keep it from becoming soil again, if we turn the dial forward again?

(Some commercial models do not use cover material, but rather have electric fans to make sure the air is always going away from the user. One of these is the Ecodomeo, which has a pedal-operated conveyor belt that carries the shit away)

The design has changed very little since the 1950’s. Have you made any modifications to make it better suit the Ecuadorian Andes and Amazon?

My line of work has been aimed at making UDDTs as easy and inexpensive to build as possible, while keeping user acceptance high.

In other words, my goal is for the building of a good dry toilet to be more a matter of a paradigm shift than a big capital investment. For this reason, I have found ways to build with readily available materials, especially since factory-made units are mostly not available in Ecuador.

One of the biggest changes I made from the start was to distribute the urine immediately via perforated hoses in the soil, instead of storing the urine in jugs, to later dilute and apply it as fertilizer among crop plants.

Organic farmers looking for every bit of natural fertilizer for their plants might be willing to do the latter, but the average user will not want to deal with smelly, fermenting urine every few days. In most of my designs, these hoses are buried 10 cm below the surface of the soil, among productive plants, like fruit trees, that can put the nutrients to good use.

In the interest of making UDDTs accessible to everyone, I published a paper in the Austrian online magazine, Sustainable Sanitation Practice, on Simple UDDTs that may be built with recycled and other readily available materials, such as disposable plastic bottles and wood: Some of the models shown here cost close to nothing.

Another surprising innovation is the storage of feces in the ubiquitous, woven, polypropylene plastic sacks used to sell rice, flour and many other products. These make excellent receptacles for this use, since humidity can evaporate out and oxygen can filter in, but flies, smells and pathogens cannot get in or out.

At first glance, people would imagine liquids oozing out, but they never do, thanks to the dry and absorbent cover material. Also, these sacks last for years and years, if they are not exposed to the sun’s UV rays. One of the biggest advantages of using interchangeable containers, like sacks, is that, at the first sign of  any problems with smell or flies, you can simply change the container and the problem is resolved immediately. Another is that the feces get covered better in a small container, as compared to a big chamber.

One of the most practical ways to use these sacks is to place them as liners of plastic bins, so the sacks are held open nicely and it is easy to change them. It is also good to make holes in the bottom of the bin, and have it propped up off the ground, to allow humidity to evaporate out and for oxygen to get in, since all the worst smells associated with latrines and sewer lines are generated by bacteria that live in the absence of oxygen.

Even more surprising for many, I have found that the finished compost from this system is the best material to cover new shit. Many of the right soil microbes are still there, likely in an inactive state (like fungal spores and bacterial endospores), ready to jump back into action when there is more shit (with its moisture) to have a party in.

In this way, natural selection and the rapid evolution of microbes are working in our favor, helping them get more efficient at breaking down exactly our shit, in exactly the conditions we keep them in. In contrast, the system of water-based toilets and trying to kill the germs in a short time with chemicals is a recipe for evolution to produce microbes that are more and more resistant to the chemicals used and that are potentially more and more virulent in disease

This recycling of cover material makes the operation of UDDTs much more practical and inexpensive, especially in cities and isolated locations, since new cover material does not need to be acquired and transported constantly, nor does much of the finished compost need to trucked away. That which does have to go would not have to go very far, if neighbors, nearby neighborhoods or nearby cities sign up for UDDTs or if urban agriculture is being done.

Another good reason to use the finished compost as cover material is that it filters odors much more efficiently than most other materials, removing and breaking down up to 99% of volatile organic compounds.

It has also been shown to eliminate 75% of the reduced sulfur compound emissions that most contribute to the characteristic aroma of shit in a laboratory study of conditions similar to those of commercial composting operations (Büyüksönmez et al. 2012, ), and up to 97% of the stench from landfills (Hurst et al. 2005)

There have been a couple of isolated cases of dogs or rats being attracted by the odor and messing with the sack that is receiving the feces, but only when sawdust was being used a cover material, not when finished compost was being used (and this is another reason for the plastic bin mentioned above).

Hygiene Hypothesis of Disease

Furthermore, there is research showing that children who grow up in overly clean and disinfected homes, without contact with soil, have a much higher incidence of asthma and allergies, since their immune systems do not have anything to train on.





 
So, having soil-like decomposed feces in the bathroom as cover material may well be a health benefit, instead of a health risk like one might suspect, as long as we are certain that the actual pathogens have died during its storage or treatment.

Humans evolved in complete ecosystems, including all the normal microbes, not in sterilized boxes, so it would make sense that bringing more parts of the ecosystem into the city would make it healthier for people.

This is all the more reason to build green, living roofs and vertical gardens on urban apartment buildings (and I have figured out how to do this with disposable Coke bottles).

At the moment, you are working with Achuar communities to implement this system. Has it been difficult to explain the environmental and health benefits of this system? What are some of the problems and breakthroughs you have had?

Changing anyone’s toilet habits is an imminently cultural endeavor and it is usually an uphill battle. People need to understand the concept, but, almost more importantly, they need to see and smell that UDDTs work.

I have built UDDTs with a variety of ethnic groups here in Ecuador, including mestizos, Kichwa, Shuar, Achuar, Waorani, and a little bit among the Secoyas. Of these, the Achuar have, so far, shown the greatest degree of acceptance. They are culturally very hygienic and traditionally live in houses scattered widely out in the forest, so they always had lots of forest to hygienically deposit their feces into. They covered them with soil and leaves, where the ecosystem absorbs them, without anyone else having contact with them.

The Achuar have only had permanent contact with white people starting in about 1970, when schools and landing strips began to be built and they started settling fairly densely around these.
It is also worth remembering that all the worst diseases were brought by the Europeans and it is estimated that 90% of the indigenous people in America died of those diseases when Europeans first came to America.

I think that potentially the Achuar have been quite concerned about fecal contamination for the last several decades, since they started living together in villages. Each family could be fairly certain of its own health and not so certain of that of the others, but all the children come together daily at the school and do their business behind the same trees. Also, it is a matter of privacy, since some of the villages are pretty large, with the houses fairly close to one another.

When I explain UDDTs to them, I emphasize the fact that, with open defecation in the woods, all these microbial enemies are set free, ready to attack us at any moment, whereas, with a dry toilet, these enemies are jailed up until they all die. They usually get the idea very quickly, but it is still a process to get them to build and use them, since old habits die slowly in any group of people.
In the last year and a half, we have built 31 UDDTs in 15 Achuar villages with the ACRA Foundation (of Italy) and the Chankuap Foundation (of Macas, Ecuador), with support from the European Union and the Municipality of Taisha 

Over several years, the Pachamama Foundation and I have built over 21 UDDTs in the Achuar villages of Pumpuentsa and Kurintsa, with a high degree of acceptance
More are being built all the time and volunteers are welcome to help with this. As I write this, the Achuar village of Juyukamentsa is organizing to build UDDTs for each of 16 families and I would like to find a volunteer to help them, especially to contribute to good replication of the design, wood preservation, and education about their proper use and maintenance.

So if the Amazonian Achuar tribe can be convinced, could your average Australian, European, or North American can be convinced as well? Can you envision a time when the whole of humanity uses this system or are our heads too far stuck up our collective asses to change our behavior for the better?

At first glance, this may seem like a system that is only applicable for hippies, organic farmers, and Indians out in the woods, but, in reality, it is a prime alternative for everyone who wants to be civilized with their neighbors, future generations, and Nature. It is also fully feasible in cities, especially if the relatively small amount of shit is stored on-site during its jail sentence and is then recycled as cover material, while the urine and excess soil is used locally in urban agriculture. (Remember the vertical gardens I mentioned?)

We can also greatly shorten the jail sentence by storing the shit in solar ovens, potentially down to less than a day of good sun, since all we need to kill fecal pathogens is 7 minutes at 70°C, 30 minutes at 65°C, 2 hours at 60°C, 15 hours at 55°C, or 3 days at 50°C. (Feacham et al. 1983 and Strauch 1991, 1998, cited by Richard Higgins)

This is also more practical than cooking lunch in a solar oven, since untimely clouds do not make us put up with hunger.

The trick is to make these toilets as easy-to-use and presentable as possible. We currently ask users to add a cup of cover material after each use, but they do not always remember to do so and they often do not aim very well, spilling it into the urine funnel and around the toilet. For this reason, mechanisms are being worked out to add the cover material mechanically, such as in one project (that I was marginally involved in) that works via a pedal:


I even have a design in mind in which the user will not have to remember to step on a pedal, nor would it involve electronic sensors.
Another factor is that many users will not want to deal with the shit and the piss. This can be resolved by setting up service-provider companies that come to homes and offices to change the containers, hygienically process the contents, and (optimally) put the resulting fertilizers back to work in their own agriculture.

With these companies applying the final products in agriculture themselves, this would increase the reliability that everything gets its proper treatment, while converting it back to delicious fruits and vegetables, which will be infinitely easier to market than the pee and the poop.

This nutrient recycling is logical and necessary if we want to have sustainable agriculture and food security. An adult eats a lot of food, but is not growing, so all the nutrients eventually come back out and, if we give them back to our crop plants, they have exactly what they need to make our food again (together with solar energy).

In this way, we can forget about chemical fertilizers, if we also have a stable population size. Of course, we have to eventually forget about chemical fertilizers, because they come from non-renewable sources.

Commercial ammonia and urea, for nitrogenous fertilizer, are produced with natural gas from oil wells (as a hydrogen source to combine with nitrogen from the air), and natural gas is already starting to run out, with the peak of production estimated to occur in 2020

It is even estimated that half of the protein found in present-day human beings was made with nitrogen originally fixed by this artificial process, thus being one more case of fossil fuels subsidizing economic and population growth.

Phosphorus is also a finite, non-renewable, unreplaceable resource and phosphoric rock extraction is estimated to peak around 2035, with reserves remaining mainly in Morocco after that. Peak Phosphorous is the scariest thing you’ve never heard of.

UDDTs are an important tool for combating Global Climate Disruption more CO2 absorbed by fertilizing plants and trees,more carbon sequestered into the soil by integrating organic matter,less methane emitted by avoiding anaerobic fermentation of feces in water,less need for chemical fertilizers (another big source of GHGs),less use of petroleum for pumping and treating water,less need for cement for building big sewers (since cement production is a big source of CO2.

Improved water-holding capacity of soils, in the face of droughts, easy construction above the high water line (or on a floating structure), in the face of floods,less demand for precious clean water.

Many rule out the mainstreaming of these dry toilets, as they cannot imagine the masses changing their toilet habits. This sort of toilet is not for everyone, but it is for everyone who wants to build a sustainable future for their children and those who do not learn to recycle nutrients will eventually go the way of the dinosaurs.

The Chinese have been recycling nutrients into the soil for thousands of years and this is one of the reasons they have had a continuous, advanced culture for such a long time. Recycling animal and human dung is the key to sustainable farming

Of course, they have not always done so in such an organized way, but there are now more than a million modern UDDTs functioning in China

I am convinced that more people can learn to do what cats do by instinct: cover their shit with soil. Let’s keep water clean by keeping shit dirty.

Thank you so much for sharing your time and knowledge! To follow Chris Canaday and his team’s work, check out these websites: http://inodoroseco.blogspot.com/ http://omaere.wordpress.com/

A Free Minimalist UDDT (part 2)

Discussion

“Conventional wisdom” or fecophobia (the irrational fear of feces) may lead people to have the following doubts about this system:

Couldn’t the fecal pathogens get out through the woven cloth of the sack?

Aside from hookworm larvae, fecal pathogens do not actively move anywhere and just wait passively to get washed into someone’s drinking water, brushed onto someone’s unwashed hands before they eat, or carried by flies to someone else’s food. These are the risks of open defecation, with fecal pathogens set loose in the environment. Liquids do not flow out of these sacks, given the dry cover material we add after each use, the separation of the urine, and the protection against the rain. The permeability of the woven cloth is actually a positive thing, since this allows humidity to evaporate out and oxygen to filter in (without smell or flies coming or going), so the feces can decompose normally, with the pathogens dying off at an exponential rate. See an example of letting feces decompose in these woven sacks in this video.

As shown in this graph from the Humanure Handbook by Joseph Jenkins, fecal coliform bacteria die in the soil at an exponential rate.

Getting back to the hookworm larvae, they only travel through moist sandy or loamy soil (not clay), so some sticks or stones may be placed under the sack when it is placed under that bridge, and wood ash (which is alkaline) may also be placed on, around, and under the sacks. Furthermore, hookworms are not usually life-threatening, nor are they terribly common, with “only” up to some 740 million persons infected in the world, mostly in Africa and Southeast Asia. It is reasonably easy to check if people have them (using a microscope) and to wipe them out with chemicals or with natural alternatives, such as papaya seeds. Plus we should always remember that hookworm larvae can only be in the feces if the users have these worms. Pathogens cannot come out of nowhere, and, in the case of hookworms, the biggest factor is dogs practicing open defecation and the larvae crawling into people’s feet. (If you do not know what hookworms look like, see this article in the Examiner. Hookworms do not just eat people’s food, but instead their blood. They were clearly the inspiration for the creature in the movie Alien.)

Can we be absolutely sure that all the pathogens will die and that no one could possibly ever get sick via this system?

No. Someone could come along and open the sack before it is time, without reading the tag, but any system can go wrong if not used right. What we can be sure about is that all the fecal pathogens are still alive and kicking in people’s fresh feces that might otherwise go straight into the environment. We also know that these pathogens die off at an exponential rate as feces decompose. The important thing is to keep these nasties jailed up while this is happening and every day of containment is a victory in the war against disease. Essentially all of these pathogens are anaerobes adapted to live in the absence of oxygen, in the aqueous habitat inside our guts, and there is only a certain amount of time they can hang on in a dry, oxygenated substrate before infecting the next person. Given this situation, the most persistent fecal pathogens have evolved desiccation-resistant packaging, like the amoebic cyst and the shell of the Ascaris egg, but even these can only protect them for a certain amount of time.

A key factor is the rambunctious and relentless nature of the microbes in rich organic soil, eating everything that does not eat them first. Most pathogenic microbes would be easy prey to soil organisms and it has been shown that fecal bacteria die-off faster in species-rich soil, as I recommend using here, optimally with the reuse of finished compost as cover material, with exactly the microbes that broke down the feces of the previous cycle, and which are not human pathogens.

Schönning and Stenström (2004) recommend storing the feces, with an ample amount of wood ash or mineral lime for over 2 years in the Temperate Zone and 1 year in the Tropics. Personally, I think this is overcautious, especially in the biodiverse, warm Tropics, but these detention times can easily be applied if there is enough space and it makes people feel more comfortable. These times refer to the most persistent fecal pathogens, which are the eggs of the Ascaris Giant Roundworm, and all the really dangerous microbial pathogens are wiped out in less than three months. We have done trials to look for Ascaris eggs in our fecal compost, here in Amazonian Ecuador, and have yet to find any beyond four months of decomposition. More trials need to be done and a simpler, more conclusive protocol that mostly only requires a microscope needs to be developed. And even I store the feces for over a year, for more peace of mind of all the users.

No one wants to go on record recommending a detention time that may potentially allow someone to get sick, and this is especially the case with governmental and international organizations. I am nonetheless willing to go out on this limb, given that the worst alternative is to continue with the currently abundant cases of open defecation, raw sewage going straight into so many rivers and bays, and 2.6 billion people in the world that do not have any sort of decent toilet. And, if over time, we find that we should modify these suggested detention times (longer or shorter), we can do so.

Aren’t we supposed to store urine for a number of months to sanitize it before applying it on the soil?

This concern is due to the possibility that feces may have contaminated the urine through people using the UDDTs improperly or having accidents … and this is very unlikely with this “bare bones UDDT”, in which the user holds the urinal right where it needs to be. If an accident were to happen, the user could dump the urine in a hole in the ground and cover it up, instead of spreading it on the surface of the soil. In places where there is the Bilharzia parasite, Schistosoma haematobium, urine should be spread on the soil far from lakes and rivers, so that this parasite cannot get to the freshwater snails it needs to infect in order to continue its life cycle.

Won’t some animal, like a dog or a rat, tear open the sack and spread this dangerous material around?

Experience has shown that they do not, especially if we are using soil as a cover material, in particular that special recycled soil. There have been a couple of cases of mischievous dogs, but only when pure sawdust was being used as the cover material. Soil and finished compost are also among the best filters for odors.

Fecophobia aside, other important questions can arise:

Why should we protect the sacks from the sun?   

Wouldn’t the solar rays help to kill the pathogens?

Yes, they would, but the ultraviolet light also destroys the polypropylene plastic strands of the sacks. Solar ovens that take this into account would be a good idea (and we can be much more patient about baking feces for sanitation than about baking lunch for our urgent hunger). According to the following graph, we only need to achieve 65°C for an hour to kill all of the fecal pathogens, and this is much easier than the 100°C required to boil water. One time, a student and I made a simple solar oven from recycled materials, and we apparently got to above 80° C, because the PET plastic Coke bottle got deformed and the Ascaris eggs held within were also seen under the microscope to be deformed and almost certainly dead.

A graph showing the time necessary for various human fecal pathogens to die at different temperatures, from Feachem, R.G., Bradley, D.J., Garelick, H. and Mara, D.D. 1983. Sanitation and Disease – Health aspects of excreta and waste water management. John Wiley and Sons, Chichester, UK (as reproduced in Schönning and Stenström 2004). For example, all pathogens die within one hour at 65° C, or within a month at 45° C.

What if we aren’t quite so broke and want something nicer?

You can do it. If your soil is fairly dry and absorbent and never gets flooded, think about making an ArborLoo, which is a lightweight outhouse that gets placed on one and another one-meter-deep holes where trees later get planted, like this one we made from mostly recycled materials. Remember to add a cup of soil, dry leaves or ashes with each use. If you do not have room to plant an infinite number of trees, you can plant vegetables, like pumpkins, and dig a new hole in the same spot after at least two years.

Also, check out the Simple UDDTs I published in Sustainable Sanitation Practice and various other models on my blog, some of which have beautiful ceramic floors set into thin ferrocement that only needs a half a sack of cement.  And set up a TippyTap to wash your hands.

 What about all the billions of people in the world who wash their back sides with water?

I have been thinking about all the billions of “washers” in the world, who use water for anal cleansing, and how they could use this Free UDDT … and have come up with the following solution. A second Ecological Urinal could be made and marked “Anal and Hand Washwater”, which would be laid on the ground, or propped nearly on the ground, to catch this water. (The lip on this urinal can be bigger to prevent this dirty water from coming out, and two sticks in the ground can prevent it from rolling.) A TippyTap could provide this water, such that the user can step on its pedal to acquire water for washing, without touching the vessel or contaminating its contents. After anal cleansing, the user can stand the urinal up and continue washing his or her hands.

(A TippyTap is a plastic bottle hung on a pole, with another stick on a string that one steps on to tip it and receive a stream of water through a hole in the bottle that was made with a red-hot nail. Standard versions can be seen at http://www.tippytap.org and a version that fills automatically with the rain can be seen at http://inodoroseco.blogspot.com/2012/04/aumentamos-un-tacho.html )

This little bit of blackwater could be poured into a narrow hole in the ground (a “soak pit”), like a post hole, which could be filled with stones, especially if there is a tendency for the walls to cave in. One could also put a plank as a lid to keep flies and smells from coming and going. If the site has really high groundwater or flooding, some kind of Constructed Wetland of plants would be called for to purify this wastewater.

And if we want to sit …?

You can build a bench, as can be seen on my blog, but I do want to remind you that squatting is the most natural position for defecation (which everyone used for millions of years) therefore:

• there is less constipation,
• there are fewer hemorrhoids,
• it is more hygienic (since genitals do not touch anything),
• it is more accessible for small children, and
• the evacuation is more complete.

It is also usually easier and more economical to build for squatting, plus there is better separation of the urine.

Where could this go?

By using this minimalist do-it-yourself toilet, people can not only resolve this sanitary problem themselves immediately, but they can also demonstrate to governments, foundations, and others that they understand and embrace the concept and practice of Urine-diverting Dry Toilets. Many planners and decision-makers would discard this option as a utopian dream that could never be feasible, but in reality local citizens are often much more practical, proactive and down-to-earth than their “leaders”. Once people demonstrate that they can properly manage this bare-bones UDDT, governments and foundations would be much more confident in building fancier, permanent units for these same users. Too many UDDTs have been built and given to the users, with everyone simply hoping that they will use them correctly, and then they are abandoned or misused, because the users were not adequately prepared and convinced of the system.

In fact, this simple toilet could be used as a test for these users to confirm their spot on the list of permanent and elegant UDDTs to be built. After a week of use, someone could visit to see how they have been used, and this would put pressure on them to actually understand and use the toilet and to actually use it properly, since no one would want to be crossed off the list for being messy or not being able to follow instructions.

This design can thus be considered a low but solid rung in the ladder of increasingly user-friendly UDDTs. With it, those 2.6 billion could quickly have a toilet, maybe with some creative redistribution of these plastic “wastes”, especially considering that, since these polypropylene sacks are protected from the damaging rays of the sun, they can be used again and again, year after year. This toilet is accessible to anyone in the world who can rescue a few selected things out of the trash and has a clear decision to keep the environment cleaner and more productive.

 
If you have any questions or suggestions about this simple toilet, please let me know. I also invite you to read more about the current problems of sanitation in this interview and more about Urine-diverting Dry Toilets in this interview.

 Keep water clean 
by keeping sh*t dirty.