Closing Cycles

In the previous post we dealt with the most basic of needs both for the site itself and for the people working on it: water. Having water on demand is crucial if you want to spend more than a few hours in the site. Following this logic, the next most important work of infrastructure would be a toilet and a roof. If you want to spend a whole day on the site you will want to rest from the heat of midday or get cover when it starts raining. And eventually you will also need to go to the little room, too.

We built the dry toilet first. A dry toilet is one that runs without flowing water. Not to be confused with a “hole-on-the-ground” latrine, which are typically a sanitary disaster, a well designed dry toilet is near to odorless, it doesn’t attract pests or spread disease and it is a very efficient means of waste management. The main idea of the design is to separate liquid from solid waste, so that the latter can decompose in an aerobic process, as opposed to the anaerobic version, which is typically responsible for bad odors and disease.

The urine is captured by a small cup positioned anatomically optimally for both sexes, and is routed through a hose away from the hut and into a 1-meter hole filled with gravel. Urine is sterile and filled with beneficial minerals, so it can be disposed of directly into the ground without problems. The solid waste falls into a plastic drum mounted on wheels, so that it can be rotated from the outside of the hut. After each use, a scoop or two of saw-dust is added, to balance the nitrogen-rich feces with a carbon-based material to help the natural decomposition process.  If you rotate it in one direction, the lid closes and the pyramid of waste can be flattened without touching it. If you rotate in the other direction, the mix can be emptied into a container placed below the drum. It is very important to enclose the drum in a sealed chamber, so that no animals or insects can enter it. For this purpose, the toilet needs to have a lid that closes tightly over the chamber. Additionally, we have installed a small fan that directs the flow of air (and that way also of any occurring odor) into a chimney away from the inside of the hut. We don’t use the fan, because we noticed it is not needed.

Usually the decomposition process takes about 4-6 months and the end product is basically natural fertilizer, that dos not resemble the original waste at all, but has become a loose, earth-like, earth-smelling material, which is now ready to be safely used on gardens and trees.

This is a low-budget, eco-friendly solution that does not waste fresh water and does not need septic tanks or any concrete. So instead of diluting your waste problems in drinking water, the way we do it in cities, here we recycle it intelligently and reuse it. This is truly the alchemy of waste management.