Technology selection and comparative performance of source-separating wastewater management systems in Sweden and The...

The research described in this paper has evaluated five demonstration projects with source-separating sanitation at neighbourhood scale, 10 years or more after their establishment. It presents the results of two systems with local grey water treatment in The Netherlands and three sites with urine separation in Sweden. The study has focused on (1) the drivers and barriers of the stakeholders that were responsible for project implementation and (2) the comparative performance of the source separation systems after their establishment. In The Netherlands the main drivers were water use reduction, combating sewer overflows and reduction of emissions. For the Swedish cases the main drivers of the involved actors were nutrient recycling, emission reduction and an active policy of the local government. The main barriers in all cases were higher investment costs and low experience with new sanitation approaches systems compared with the conventional system. Three of the sites showed a lower performance with respect to public health because effluent monitoring protocols for the grey water treatment systems were not in place or people could have direct contact with faeces. Lack of operation and maintenance is a cause of occasional failure for the grey water treatment systems, while the dominant failure reason for the urine separation systems was pipe clogging. The inventory showed that source-separating sanitation systems have a high potential to save or recover resources (water and nutrients).