Hi Everyone,
I just came across this analysis, by The Union of Concerned Scientists, of the advantages and disadvantages of biodegradable plastics, which I suggest should be read by anyone planning to build a toilet around such a product.
www.grinningplanet.com/articles/trash-re...s-of-bioplastics.htm
In summary:
// They are not really biodegradable, unless put into very specialized composting installations, of which there are only about 100 in the USA. (Elisabeth mentioned some time back on this Forum that some "biodegradable" plastic bags lasted years in her backyard compost pile). So they would only make sense in UDDTs if such specialized thermophilic composting is also done.
// They have a great impact on the environment, comparable to that of plastics made from petroleum (taking into account pesticide use, GMOs, competition with people who want to eat the plants that are made into plastic, etc.).
The Grinning Planet staff added a comment that the most environmentally friendly option is to use durable, reusable things ... like the reused and reusable woven polypropylene sacks that I use in UDDTs (which are also very economical and accessible, plus they allow for water vapor to evaporate out and oxygen to filter in).
I still question whether these "biodegradable" plastics actually break down entirely to natural compounds, without contaminating soil, air or water.
If people still want to use these "biodegradable" plastics in their UDDTs, the article gives suggestions of the most environmentally friendly options on the market (as of 2009).
((Simon,
For some reason, I did not see your response, until these new messages were moved to this thread.
// I think the Wayuu Culture in the Guajira cannot be more sensitive to feces than the Achuar here in the Amazon, who are accepting UDDTs relatively well ... and because of this sensitivity, they should obviously not want feces scattered on the ground or dissolved into the water. A key thing is to explain that UDDTs, as opposed to open defecation or flush toilets, jail up all the microscopic enemies until they die.
// If the toilets are off a bit into the vegetation, people will have their privacy and no one else needs to know what they are doing (as we do with the Achuar).
// I highly suggest building for the squatting position, as this is more higienic and it is the position they have always used (see the model we build for the Achuar in Pumpuentsa at inodoroseco.blogspot.com).
// The hot, dry conditions in the Guajira are great for pathogen die-off. I would recommend using the abundant dry ambient soil as cover material (even though recycled cover material is better, as I have mentioned before, but that would them freak out and, since the conditions are great, you do not need to use the very best cover material).
//From the videos on your great website,
www.aguayuda.org, I have a better idea of the situation there and I now think that one of your best options is the ArborLoo, as long as there is no flooding, nor a high water table in the soil. Fruit trees could be planted in the full holes. Just a matter of making comfortable and acceptable lightweight privacy structures. (Also see my blog.)
))
Best wishes,
Chris Canaday