Part one The Holding Tank
The Kumasi Ventilated Improved Pit latrine (KVIP) and is the epitome of sustainability. No water, and a lifespan of at least 20 years without any maintenance except cleaning of the cubicles. This is the type of sustainable toilet we have built in Tafi Atome, Alavanyo Dzogbedze and now are building in Alavanyo Agome.
The most important part is the Pit or the holding tanks. All of the toilet deposits go into these tanks.
They are designed to be very well ventilated so no, or little, smell goes back up into the cubicles. Any flies that follow their noses onto the poo are cunningly trapped in the tank until they die. If the flys could escape they would carry germs on their legs and bodies. They can’t excape so this stops them spreading diseases.
Each tank is designed to hold about ten years, YES TEN YEARS, worth of deposits! Then the second toilet in each cubicle is opened up to start filling the neighbouring holding tank. After about 20 years the contents of the first tank have thoroughly composted killing any pathogens. This holding tank is then emptied and the process starts again. The tanks need to be very strong to survive these many years of use.