Urine and faeces from humans contains a lot of nutrients. If the nutrients from on-site wastewater treatment are recycled, the risk of polluting recipient waters decreases. Recycling nutrients is also a way to contribute towards sustainability. Today the agriculture has a net loss of nutrients that is compensated with mineral fertilizers. This net loss of nutrients can be compensated with nutrients from faeces and urine instead. Sweden has a national environmental objective stating that

"at least 60 % of phosphorus compounds present in wastewater should be recovered for use on productive land by 2015 and at least half of this amount should be returned to arable land". Source separated wastewater systems contribute to fulfil the Swedish environmental objective by collecting the nutrients in faeces and urine. These nutrients can be used as fertilizers after appropriate treatment. There is a potential hazard with pathogens, pharmaceuticals and heavy metals contained in these fertilizers. However the concentration of heavy metals and pharmaceuticals is lower in urine and faeces than in animal manure. If appropriate treatment for sanitising is used, the risk for pathogens is reduced. The products from source separated have a high potential to retain available plant nutrient resources and being able to substitute mineral fertilizer and at the same time prevent eutrophication.