Experiences and suggestions for collection systems for source-separated urine and faeces

Abstract

This study collects experiences from existing systems with urine diversion and dry handling of faecal matter and presents design recommendations for improved function of new systems. Urine collection and piping systems were studied in four large residential areas in Scandinavia and South Africa where urine had been collected separately for 5-9 years and dry faeces collected for 4-15 years. We found that larger (>1 toilet) urine collection systems should have odour traps. Blockages in u-bend odour traps can be efficiently prevented by cleaning the u-bend 1-4 times per year with a sewage auger, caustic soda solution or strong acetic acid. A urine pipe diameter of 75 mm and a gradient of at least 1% are recommended. In small systems without a u-bend, a diameter of 25 mm can be used in combination with a gradient of at least 4%. For faecal collection, the most important factors for good function and high acceptability of the system are diversion of the urine, small collection bins (high emptying frequency) and easy access for emptying of bins.