Posted by on Jan 20, 2013 in all posts, Mexico, Universidad de la Tierra | 1 comment

My first, major (and classy) blog entry

My first post was supposed to be a reflection on why I am here and some of the first things I have learnt. This post will eventually come, but for now I will be writing literally about how to bring your shit to life, or even better said, how to enliven your shit.

The reason why the plans were changed was because although I became part of the project just a few weeks ago, when Kelly and Udi were already in Brazil, there was some footage in Spanish from Mexico they were finding hard to comprehend in detail. Kelly was writing the post The autonomy of Poo and asked me if I could help her understand the whole process of building the poo box. I found that César Añorve’s explanation was so informative and humorous at the same time, that it deserved to be shared in its own post:

César explaining the first steps of the process. Photo by Udi

Although César calls it a poo box, it is also more formally referred to as an ecological dry toilet, precisely because it does not require the use of water and, in that way, it does not pollute rivers, seas and oceans. All this can be better understood by reading about how it is built and how it works:

Elements: (“The simplest elements in the world”)

For the poo:

  • 1 plastic bucket
  • Dry dirt
  • “dry leaves that we might find near our house”
  • “charcoal powder, which you can get for a very low price; it is the leftovers of the coalyards, here we call it cisco.” Or, one can put olotes (the corn’s cobs) in the fire and wait until they are carbonized. In this way, you can make your own coal.
  • Optional ingredients: marble or steel powder, which are sold in construction shops, very fine sand, lime.

As César said: “It is like life: the more diversity the better.”

For the pee:

  • Plastic recipient, “so that the pee does not stink while being stored”
  • Hose
  • Funnel
  • Bowl.

To place on top:

Wooden box with 3 holes:

  • One big hole on one of the sides of the box, through which the bucket is introduced and taken out.
  • A small hole on the opposite side, not too big, but big enough for a hand and an arm to be introduced through it.
  • Hole on the top of the box, where one will sit.

Sticking the sides of the wooden box together. Photo by Udi.

How to build it:

1)      Take the bucket and throw in the dirt, the dried leaves and the coal. Add the other elements if you were able to get them.

2)      Add a small piece of flat wood inside the box, under the smallest side hole.

3)      Place the box over the bucket.

4)      Put the bowl on the small piece of wood you have added under the small side hole.

¡So simple!

There is a slightly more complex option in which instead of the wooden box, one can build a whole chamber with a door through which the bucket can be placed and removed. In this model, the pee bowl or container is already connected to the recipient through the hose, so one does not need to empty the bowl every time the toilet is used.

All the elements of the dry toilet put together. In this case, using the chamber instead of the wooden box. Picture taken from César’s book “The ABC’s of Ecological Sanitation”

Proper use of the dry toilet:

1)      When sitting on the toilet make sure that the feces fall into the bucket and the urine into the bowl or separator. This separation is the key to the toilet’s proper functioning: it avoids humidity and bad odors. “This separation of pee and poo is pretty easy for men. Women can manipulate the bowl”, introducing their hand through the smaller hole. “Women’s perspective has been taken into account for every design of the poo-box.” It has been tried before by many of César’s friends who were then consulted about the position in which they preferred the bowl to be (higher, lower, the distance it should keep from the bucket, etc)

2)      If you have built the more complex version of the dry toilet, the urine will go directly to the recipient though the hose. If you have the simpler version with the bowl, before throwing it into the recipient using the hose and the funnel, you can take a small sip, the size of a full spoon. Urine is very good for the health.

3)      After every use of the toilet, cover the excrement in the bucket with a mixture of fine dry soil and lime and/or dry leaves. This dries the surface, avoiding bad odors and the proliferation of insects.

4)      After doing this, always cover the bucket.

What happens with the poo and the pee once they have left our bodies?

Urine as fertilizer

Urine contains a high concentration of nutrients such as nitrogen, phosphorus and potassium. Also, it contains urea, which after a time turns into ammonia, the fertilizer most used in agriculture. Therefore, the urine stored in the container can be mixed with water and used as a fertilizer for garden plants. The proportion should be one part urine, ten parts water. By doing this, a family of six people can produce more than five thousand liters of fertilizer every year. Options for the use of the urine:

  • Apply directly to the base of the plants.
  • Spray it on plants and fruit trees using a hose.
  • Add to the compost.

Excrement as compost

When you see that the bucket is full:

1)      Remove it from the box or chamber and replace it with another bucket. The bucket that has been removed needs to sit for enough time until it dries completely.

2)      After this period, open it. You will be able to see that the dried leaves are covered with a white thing. This will be because of the transformation carried out by the microorganisms. The excrement has dried out and has been converted into an “odorless granular dust”.

3)      You can use this rich compost to fertilize a garden or fruit trees just by throwing it to the earth, or you can take a big flower pot and throw the content of the bucket into the pot. (By doing this, the same family of six can produce 500 litres of organic compost each year.)

The result: the odorless compost. Photo by Udi

If you chose the latter,

1)      Add food leftovers and earthworms to the compost in the pot

2)      Add a little bit more dried leaves on top of everything.

3)      Compact the mixture inside the pot.

4)      Repeat the whole procedure as many times as you need until you have filled the whole pot. You will be able to appreciate how the content of the pot reduces constantly. These are the microorganisms doing their work.

5)      After a few days, start observing the content of the pot attentively: you will be able to appreciate how a plant starts growing. “In my case, I got and aguacate and a chilli”.


The process that has taken place here is amazing. Our waste, which we thought dead, which we thought of as that, as waste, has been literally transformed into a living being, into a plant. When I heard Cesar’s explanation for the first time I could not believe this had happened. This got me thinking, and although the post has been written in a slightly “funny” tone, truth is I felt this knowledge had to be shared, since the idea of the dry toilet is so innovative and interesting to me on so many levels:

In the first place, there is the most obvious question of pollution. By using a dry toilet, we are not polluting the water we drink. This is a big issue in many places in the world: many diseases are generated by drinking water which has been polluted with excrements. “When we avoid using water to transport excrement, this is a radical action which can contribute to returning the sacred character that water may have had before the era of sewage systems”. At the same time, from a more practical point of view, there is the question of the re-using. Our excrements and urine are not waste but are re-used. This represents and economic advantage, because we save on fertilizers and are able to produce more vegetables and fruit. What is being created here, homemade, is a natural storage of nutrients.

This last point is also very interesting. By using a dry toilet we are making ourselves responsible for our own waste and, at the same time, generating our own compost and fertilizers. We are being self-sufficient. This relates to the idea of autonomy Udi and Kelly developed in one of their posts (Learning Autonomy). Before reading it, I had never thought of autonomy in this way, a collective autonomy through which a community is capable of generating its own resources and becoming self-sufficient. At the same time, the process of autonomy also means to become conscious of our own dependencies and interdependencies and reflect and recognize them. As Kelly points out, only by considering and exploring other options we will be able to perceive and act on our dependencies. The dry toilet is one of these options. Before being introduced to it, I had not really considered the possibility of other options for my poo and pee. I had not deeply reflected on what happened to them after they left my body and I had not thought about the traditional toilet system as one of my dependencies.

Finally, in relation to recognizing our interdependencies, the toilet made me reflect not only on how we depend on the State´s sewage system but also of other interdependencies: the interdependencies within nature. The dry toilet shows very clearly and explicitly the idea of the cycle of life: the food we eat, is transformed into energy and feces and urine, which then serve as fertilizer to grow more food. It is an example of the transformations that take place in nature. And for these cycles and transformations to take place, each being needs of other beings: the soil needs the excrements to become compost, the seed needs this compost to become a plant. And also, as César explained, the earth in the pot needs the plant to continue its transformation process. Therefore, what are we, humans, if not just a part in this cycle of life? And as such, we should be taking something from the world but also giving something to it, just as with the dry toilette, through which the food we have taken is given back to the earth as compost.

Picture from César’s book “The ABC’s of Ecological Sanitation”


I know that probably most of the people that read this post will not actually build a dry toilet in their homes (It would be great, however, if you do it and you can find more information about it at the bottom of the page). Regardless, I wanted to share my reflections about what the idea of the dry toilet generated for me. It is only when we know that other options are possible, that other ways of understanding something exists, that we will be able to reconsider and re-think about our own ways.

From César’s book

* All quotes are either what César said during his class in Unitierra or direct quotes from his book The ABC’s of Ecological Sanitation.(2004, Centre for Innovation in Alternative Technology A.C., Mexico)

Cover of César’s book

**For more information write to César:

Centro de Innovación en Tecnología Alternativa A.C.

Av. San Diego No. 501,

Col. Vista Hermosa

CP 62290 Cuernavaca, Morelos, México