Septic Tanks, 2001

Septic tanks were originally part of the infrastructure for AVL-Ville. The tanks provide a simple and conventional way for treating black water (human waste). The unit includes a faecal pump, which breaks up pieces of excrement. Heavier parts in the waste water sink to the bottom of the tank; more volatile lighter parts float on the surface; while the middle layer of cleaner water goes to the next tank, where the same process of floating and sucking continues. While the sewage remains in the tank, the water is purified by means of fermentation and bacterial culture. Finally the water is pumped to a reed filter, which cleans the water once again.