Urine Diversion Dry Toilet outside

Urine Diversion Dry Toilet (UDDT)


The Urine Diversion Dry Toilet (UDDT) is a special type of composting toilet, designed especially for regions where access to drinking water and sanitation facilities is scarce. Most of the existing toilet systems (pit latrines) are a health risks. Not just for the users even for the people in the surroundings. Pits which are not sealed are leading a mix of urine and faeces straight into to the groundwater were others are getting their drinking water from. The UDDT is one option where contaminating drinking water is avoided.



A UDDT is a waterless, diverting toilet system. It means NO WATER is needed for flushing the toilet after it has been used.

Diversion because urine and faeces are separated already in the lid

Dry because additives (ash, saw dust) are speeding up the drying process of the faeces

A chamber below the toilet lid is needed for housing a collection bucket for faeces and the canister for urine. This chamber is accessible from behind the toilet stance for maintenance and operation.

Good ventilation is another important fact for UDDT’s. Ventilation is ensured with a big pipe (painted black) leading from the chamber over the roof (chimney effect: Pipe is heating through sun, air is rising up). If ventilation is not ensured flies and insects are attracted by the smell.

All UDDT’s should also be equipped with Urinals (for males) in terms of hygiene and functionality of the systems.

No water should enter in the opening behind!

The bucket is filled up after around 6month. It means another process is starting. An empty bucket has to be placed below, meanwhile the full bucket is drying up for six month. After six month the dry material has to be processed to compost and the end product and the buckets should be exchanged, emptied bucket should replace the filled up bucket. Process is starting again. Additionally a composting area is needed.


Key Facts
  • Solution for households, communities, social institutions or public buildings
  • Additives have to be enough (e.g. ash from the kitchen)
  • Maintenance and operation (emptying bucket and canister, cleaning of toilet)
  • Awareness rising has to be provided for the new users => Handling of faeces!



+ No contamination of drinking water

+ Construction done with local materials

+ No water for flushing the toilet

+ Fertilizer for plants from collected Urine

+ Adequate for small settings (e.g. households) up to big applications (e.g. staff houses at hospital and boarding schools)


  • Cultural problems in handling faeces
  • Training / awareness for users necessary
  • System as good as the users