Technology S05
The Fossa Alterna is a short cycle alternating, waterless (dry) double pit technology. Compared to the double VIP (S.4) which is just designed to collect, store and partially treat excreta, the Fossa Alterna is designed to make an earth-like product that can be used as a nutrient-rich soil conditioner. The Fossa Alterna is dug to a maximum depth of 1.5 m and requires a constant input of cover material (soil, ash, and/or leaves).