Experience from Norway shows that separate treatment of blackwater and greywater nearly achieves "zero emission" and almost complete recycling. Organic household waste can be treated in the same process as the blackwater and yield a fertiliser/soil amendment and energy. The water consumption can be reduced by up to 50%. Compact and technically simple greywater treatment systems facilitate decentralised treatment even in urban areas, reducing the need for a secondary piping and pumping system for transport of untreated wastewater.
JENSSEN, P.D. (2002): Design and Performance of Ecological Sanitation Systems in Norway. (= (=Proceedings of the Proceedings of the First International Conference on Ecological Sanitation 5-8 November 2001) ). Nanning, China: EcoSanRes URL [Accessed: 21.11.2012]