domingo, 20 de octubre de 2013

A Free Minimalist UDDT (part 1)

A Free Minimalist Urine-diverting Dry Toilet (UDDT) for the Unhoused, Poor or Disaster-stricken
(This was first graciously published at
after they had asked me about simple options for homeless people.) 
(Para español, vea:

Shifting from wasteful, expensive, contaminating, water-based toilets to decentralized, environmentally friendly, dry toilets should be more a matter of paradigm shift than capital investment. This is especially true for those who have little money, are potentially living on the street, or are in the upheaval of an emergency.

The key things that a UDDT needs to do are: (1) jail up the potentially dangerous feces that may transmit many terrible diseases (including diarrhea, cholera, typhoid, and intestinal worm eggs) long enough for these to die and (2) set the urine free on the soil, where it is excellent fertilizer for the plants and transmits no disease. This separation also greatly reduces the potential for stench and keeps the volume of dangerous material small and manageable.

The following minimalist toilet is entirely functional and is made with just a few readily available materials that can be rescued from the garbage:
  • Two 4-liter plastic bottles, like those used to sell bleach.
  • 50 centimeters of tape.
  • 2 meters of string.
  • Four sticks, 25 centimeters long (or a box the right size).
  • Some normal, woven, polypropylene sacks, like those used to sell 100 pounds of flour, rice, or whatever. Biodegradable, jute bags (like coffee sacks) can also be used and even have an advantage (see #7, below).
  • A small sheet of plastic.
(1)   Make a portable, ecological urinal from the two bottles, cutting one diagonally (as shown) and joining them together mouth-to-mouth with tape and then firmly with string. This is a very useful item, even if one has a more up-scale outhouse, as it can be used for peeing next to bed in the middle of the night, without having to go out into the dark among snakes, insects, rapists or other creatures. It can also be used during the day wherever there is enough privacy.
While standing with urine in it, this urinal emits very little smell, since the mouths of the bottles are small and the top bottle blocks the movement of air across these mouths. Each day, it gets rinsed with water to avoid smell developing with the fermentation of the urine.

This costless urinal is very practical for collecting urine, diluting it with at least three times as much graywater, and pouring this excellent fertilizer on the soil among one’s crop plants … or among the ornamental plants in the city park to help them flower more beautifully. One could also dump the urine into a sewer drain, but that would waste the nutrients, increase public spending on wastewater treatment, and contribute to the formation of anoxic dead zones in rivers and oceans.

(2)   Push the four sticks into the ground, to a height of about 12 centimeters. If one prefers (or especially if the floor is cement and you cannot poke sticks into the ground), a cardboard, wooden or plastic box the right size could be used instead of the sticks.

(3)   Roll down the edge of the sack and place it over the sticks. Put in a cup of dry soil where the first deposit will fall. If you like, a layer of dry leaves can be placed in the bottom of the sack first.
(4)   Put your heels against the sack, squat down, hold the urinal inclined in front of you, and release your load of nutrients. The feces will fall neatly into the sack, while the urine flows neatly into the urinal. Then, stand up the urinal until the next convenient opportunity to spread it on the soil. Place the paper, leaves, corn cobs or whatever was used for wiping together with the feces. (Arrange for privacy however you like, maybe with palm fronds stuck in the ground.)

(5)   Put a cup of dry soil on top of the feces to cover them, control the smell, keep flies from laying their eggs, and inoculate them with beneficial decomposer soil microbes. Keep a stick in the sack to accommodate the feces and paper, facilitate them being covered adequately by the soil, and fill the space in an orderly way (always grabbing the non-sh*tty end of the stick). One of the best soils for this consists of the decomposed feces from a previous cycle, as seen here, with some sawdust mixed in if it is too compact.

(6)   When not in use, cover the whole thing tightly with a sheet of plastic to keep rain, flies and curious eyes out.

(7)   When full (to a height of nearly the 12 cm), or when the users are moving on, tie the sack shut with a tag that says something like, “Open this package of rich organic soil only after XX/X/20XX (say a year from now) when it is safe to use in agriculture” and hide it somewhere protected against the rain and sun, like under a bridge. Another option would be to bury the sack, preferably in dry, well aerated soil (potentially under that same bridge). These sacks could also be stacked on a layer of rocks or sticks and covered with a sheet of plastic to protect them from the rain (maybe under a tree to protect the plastic from the sun).

The feces should dry and decompose for at least 6 months in the Tropics or a year in Temperate Countries (longer if buried in the soil), so that the pathogens die and it is no longer dangerous.
If the users are there long enough, or come back, they can use this new soil themselves in agriculture, or recycle it as an excellent cover material for new feces in the UDDT once again. More fecophobic people might want to only put it in the bottoms of holes for planting trees, which is also a great use.
The advantage of using biodegradable, jute sacks is that one can just throw the recently filled sack in the bottom of a hole, plant a tree on top of it, and forget about it (until you wonder why the tree is growing so fast and with such luscious fruits).

(Continue reading for a discussion of this system here.)

miércoles, 9 de octubre de 2013

Primer Vistazo a los Jardines Verticales de Botellas

En estas fotos de acercamiento, podemos ver cómo el punto de contacto entre las botellas que contienen el suelo en forma vertical y las plantas que crecen en este suelo. Esta es una gran opción para convertir la heces descompuestas y la orina humana en saludables frutas, vegetales y plantas medicinales (como esta planta morada de Escansel, que es bueno para el riñón). Con estos, se puede hacer agricultura urbana, encima de las terrazas de los edificios, pegados a sus paredes o incluso formar las mismas paredes de nuevas casas.

Desean ver cómo los construyo? Favor escribirme, para que yo sepa que haya interés.

Creative Commons License
PET Bottle Vertical Gardens by Chris Canaday is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
Based on a work at
Permissions beyond the scope of this license may be available at
Sneak Peek at the Vertical Gardens made from Bottles

In these close-ups, we can see the point of contact between the bottles that hold the soil vertically and the plants that grow in this soil. This is a great alternative for safely converting human urine and decomposed feces into healthful fruits, vegetables and medicinal plants (like this purple Escansel plant, which is good for the kidney). With these, we can do urban agriculture, on the roofs of buildings, stuck to their walls, or even forming the walls of new houses.

Do you want to see how I build these? Write me, so I can know if there is interest.

jueves, 6 de junio de 2013

Un Video sobre el Manejo de Heces en Sacos

Gracias al voluntario uruguayo, Federico Fredes (, hemos hecho un lindo video bilingüe sobre cómo manejar las heces de los inodoros secos en sacos tejidos de polipropileno. También se ve el producto final --después de más que un año-- que usamos otra vez para cubrir las heces nuevas, cuando ya no representa ningún peligro y es lo mejor para controlar los olores y moscas e inocular al nuevo depósito con los microbios que decompusieron todo en la vuelta anterior. Disfruta la música de diyiridú de Australia. Todo comentario o sugerencia bienvenido.

A Video about Managing Feces in Sacks

Thanks to the Uruguayan volunteer, Federico Fredes (, we made this nice little Spanish/English video about how to manage feces from UDDTs in woven polypropylene sacks. It also shows the final product --after more than a year-- which we use to cover the new feces, when it no longer represents any danger and is the best cover material for controlling smell and flies, while inoculating the new deposit with the microbes that decomposed everything in the previous cycle. Enjoy the Australian didgeridoo music. All comments and suggestions are welcome. 

lunes, 6 de mayo de 2013

Urinarios Ecológicos / Ecological Urinals

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Los Urinarios Ecológicos tienen cada vez más popularidad. Es fácil cortar una poma de 4 litros en diágonal y unirla con cinta y piola a otra poma que ha quedado intacta. Hombres y mujeres podemos orinar directamente en este urinario, en la privacidad del dormitorio u otro cuarto, para luego dispersar este excelente fertilizante en el suelo entre las plantas. En lugares secos, o cuando se trata de plantas delicadas, es mejor diluir la orina con 3 o más veces más agua (que puede ser "aguas grises" de haber lavado los platos o de habernos bañado). Después, se le enjuaga con agua, no hay problema con olores y está listo para usarse de nuevo.

Se agradece a la Lavandería La Mocita de Puyo (que donó las pomas que habían tenido cloro), a Federico (un voluntario uruguayo que ayudó a armar estos urinarios) y a las 4 modelos.

El acompañamiento de la boa constrictor es opcional.

Ecológical Urinals

Ecological Urinals are getting more and more popular. It is easy to cut a 4-liter jug diagonally and connect it with tape and string to another, intact jug. Men and women can urinate directly into these, in the privacy of their bedrooms, to later spread this excellent fertilizer on the soil among crop plants. In dry places, or when the plants are particularly delicate, it is best to dilute the urine with 3 or more times more water (which may be "greywater" from having washed the dishes or from having bathed ourselves). Afterwards, it should be rinsed with water, to avoid any smell problem, and it is ready to use again.

Many thanks to Lavandería La Mocita in Puyo (that donated these jugs that had previously held bleach), to Federico (a Uruguayan volunteer who helped to put this batch of urinals together), and to the 4 models.

The watchful eye of the boa constrictor is optional.

domingo, 26 de agosto de 2012

Un modelo (parcialmente reciclado) de ArborLoo

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En abril, hicimos un modelo económica y ecológicamente amigable de ArborLoo, dentro de un curso de capacitación del Cuerpo de Paz, en Tumbaco, en las afueras de Quito.

El ArborLoo es un tipo de sanitario ecológico ideado por Peter Morgan (Zimbabwe), en la cual se construye una casita liviana y portátil que se coloca sobre una serie de huecos poco profundos, donde luego se siembran árboles. Es aplicable solo en lugares con tierras relativamente secas y absorbentes. Uno de sus mayores ventajas es las heces se quedan encapsuladas en la tierra y nadie tiene que manejarlas (hasta que estén convertidas en deliciosas frutas en el árbol). (Vea los libros de Peter en

Los más sobresalientes aspectos del nuevo modelo son:
  • El techo es hecho de plástico PET cortado de botellas desechables. (Pondré más detalle sobre cómo se hace esto en otra entrada). Esto permite entrar más luz y aire, además de reducir su costo y su huella ecológica.
  • Tiene un tubo de ventilación, hecho de botellas desechables de plástico PET (3 litros, 12 cm diámetro), que va desde la banca hasta arriba del techo, para desalojar posibles olores.
  • La pared de privacidad es de plástico blanco, lo cual también permite pasar gran cantidad de luz.
  • La puerta está hecha de cartones de TetraPak, abiertos y cosidos y luego grapados sobre un marco de madera. TetraPak es muy durable, muy abundante y poco reciclable (de forma convencional).
  • Sus dimensiones son 80 cm de ancho, 120 cm de largo, y 2 m de alto. La mitad del largo es el piso y la otra mitad es la banca. La banca es de 38 cm de alto. El hueco cilíndrico en la tierra es de 100 cm de profundo y 50 cm en diámetro.
  • Una capa de vinil cubre el piso y la banca, para mayor elegancia y para facilitar su limpieza. También cubre la superficie interior de la banca, donde choca la orina.
  • La madera es utilizada solo en el esqueleto, piso y banca, así reduciendo el peso de la casita y su contribución a la deforestación. (Se puede proteger la madera con aceite quemado de motores.)
  • Como toda la estructura es liviana y podría ser llevada por el viento, es sujetada a la tierra por medio de una soga y dos estacas.
  • Los usuarios deben agregar una taza de tierra seca, cenizas, etc. después de cada depósito.
Opinamos que este modelo podrá tener gran aplicación en lugares donde la tierra es absorbente y donde hay espacio para sembrar árboles. Si no hay mucho espacio, se puede sembrar especies que viven poco tiempo, como el Banano y el Tomate de Árbol. Si la tierra no está tan absorbente, se podría mantener separada la orina (como en los UDDT de este blog), lo que también facilitaría su reciclaje como fertilizante.

Agradezgo mucho la ayuda de los voluntarios de Cuerpo de Paz, sus colaboradores locales y su coordinadora Eveliz.
- - -
A (largely recycled) New Model of ArborLoo

In Abril, we built an economically and ecologically friendly model of ArborLoo, within a training course on Ecological Sanitation for the Peace Corps, in Tumbaco, in the outskirts of Quito.

An ArborLoo is a type of ecological toilet that was thought up by Peter Morgan of Zimbabwe, in which a lightweight, portable outhouse is put over a series of shallow holes where trees are later planted. This is applicable only where the soil is relatively dry and absorbent. One of its greatest advantages is that the feces remain encapsulated in the earth and no one has to deal with them (until they are converted into delicious fruits on the tree). (See Peter's books on

The details:
  • The roof is made from PET plastic cut from disposable bottles. (I will post more detail on how to do this later.) This permits the entry of more light and air, in addition to reducing its cost and ecological footprint.
  • A ventilation pipe is also made from disposable PET plastic bottles (3 liters, 12 cm diameter), that reaches from the bench to above the roof, to vent possible odors.
  • The privacy walls are made of white plastic, which also lets lots of light in.
  • The door is made from TetraPak cartons, opened out and sewn together, then stapled to a wooden frame. TetraPak is very durable, abundant, and does not lend itself very well to conventional recycling.
  • Its dimensions are 80 cm wide, 120 cm long, and 2 m high. Half of the length is the floor and the other half is the bench. The bench is 38 cm high. The cylindrical hole in the ground is 100 cm deep and 50 cm diameter.
  • Linoleum covers the floor and bench, for more elegance and to facilitate cleaning. There is also linoleum on the inner surface of the bench, to protect the wood from the urine.
  • Wood is only used in the frame, floor and bench, thus reducing the weight of the outhouse and its contribution to deforestation. (The wood can be protected with used motor oil.)
  • Since the structure is so light and could be blown around by the wind, it is tied down to the ground with a rope and two stakes.
  • Users should add a cup of dry soil, ashes, etc. after each deposit.
We think this model could have wide application in places where the soil is absorbent and there is enough room to plant trees. If there is not so much room, species that do not live so long, such as Bananas or Tree Tomatoes, could be planted. If the soil is not so absorbent, urine could be kept separate (as in the UDDTs of this blog), which would also facilitate its recycling as fertilizer.

Many thanks to the Peace Corps Volunteers, their local counterparts, and their coordinator Eveliz.

lunes, 2 de abril de 2012

Aumentamos un tacho

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La idea de tener un saco destapado debajo del piso para colectar las heces asusta a muchas personas. En verdad, tenemos muy pocos problemas con esto, pero ha habido un par de casos de perros mañosos que jalan el saco (aunque aparentemente no para comer el contenido).

Esto es razón suficiente para poner más seguridad y hemos comenzado a poner el saco en un tacho plástico (de color verde en la foto) que se deslisa justo debajo del piso sobre unos pequeños postes. Esto también facilita el cambio de los sacos. Estamos usando tachos de 40 litros que las compañías de aviación han dado de baja, cortamos la parte de encima, y un saco quintalero entra justo. Además, se puede huequear un poco el fondo para permitir la evaporación de la humedad y el ingreso de oxígeno.

En la foto, Mercedes (una de las coordinadoras locales del proyecto) está lavando sus manos con el último modelo de nuestro Tippy Tap que se llena solito con la lluvia que viene del techo. Para esto, usamos pomas de 4 litros de aceite de motor, las cuales son molestosas para lavar, pero vale la pena, ya que son fuertes, abundantes y gratis. (Parece que la mejor manera de lavarlas es enjuagarlas con diluyente para pintura, remojar en agua durante más de un día para sacar las etiquetas, y lavar con agua muy caliente con detergente.)

El tacho amarillo (también dado de baja) es para las cenizas.

No se preocupen. Después, los usuarios pusieron paredes para dar privacidad.

We added a bin

     The idea of having an unprotected sack under the floor to collect feces freaks some people out. We have really had very few problems with this, but there have been a couple cases of unruly dogs that have pulled the sack loose (although not apparently to eat the contents).

     This is reason enough to add some more security and we have started putting the sack inside a plastic container (green in the photo) that slides tightly below the floor on several small posts. This also makes it easier to change the sacks. We use 40-liter containers that aviation companies have decommissioned and give us for free, we cut the tops off, and a large, woven, polypropylene sack fits exactly into it. Also, holes can be made in the bottom, to allow humidity to evaporate out and oxygen to filter in.

     In the photo, Mercedes (one of the local coordinators of the project) is washing her hands with our latest model of Tippy Tap that fills automatically with rain from the roof. We make these with 4-liter motor-oil jugs, which are a hassle to wash, but are worthwhile, since they are strong, abundant and free. (The best procedure for washing seems to be rinsing with paint thinner, soaking for over a day to get the labels off, and washing with very hot soapy water.)

      The yellow container (also decommissioned and free) is for storing the ashes.

      Don't worry. The users later added privacy walls.

Nuevos videos y audios sobre Ecosan

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Mi amigo, Charles Thibodeau (de Québec en Canadá), subió recientemente al internet un divertido video (con versiones en español, inglés y francés) sobre los Inodoros Ecológicos Secos que hicimos con él en Tisaleo en 2010.


Nuevamente, hay más detalles sobre este proyecto en el artículo que publicamos en Sustainable Sanitation Practice (desde la página 23)

Otra amiga, Carina Baskett (de los Estados Unidos), hizo un excelente podcast de audio sobre Inodoros Ecológicos Secos, Círculos de Banano y Desinfección Solar del Agua

New Videos and Audio about EcoSan in Ecuador

My friend, Charles Thibodeau (of Québec, Canada), has uploaded a fun little video (with versions in English, French and Spanish) about the UDDTs in Tisaleo in 2010.


Once again, there are more details on this project in the article we published in Sustainable Sanitation Practice ("Elegant yet Economical UDDTs in Ecuador", starting on page 23)

Another friend, Carina Baskett (of the USA) has made a very polished and professional podcast about UDDTs, Banana Circles and Solar Disinfection of Water