Stop Flushing Fertiliser Away

From Birger Lundgren, CEO & Founder of the Blue Community Sanitation Ambassadors, Capetown, South Africa:

I read a good article in BioCycle about the fertiliser crisis and the role compost can play. Good article. But it also reminded me how strange our system is. We are surrounded by nutrients, especially nitrogen in urine, and we keep flushing them into rivers and oceans. Then we buy fertiliser somewhere else. Sorry, but that is bonkers.

We talk about the fertiliser crisis as if nitrogen has disappeared from the planet. It has not. A large part of it is passing through our own bodies every day, ending up in urine, then being flushed away. After that we spend huge amounts of money and energy trying to remove the same nutrients from wastewater before they damage rivers, lakes and oceans.

At the same time farmers are paying more for fertiliser.

Human urine is only a small part of domestic wastewater, but it carries a massive share of the nutrients. Most of the nitrogen is there, and also a large part of the phosphorus and potassium. So what do we do? We mix it with faeces, greywater, chemicals and industrial waste. Then we call it sewage. Then we build expensive treatment plants to remove the nutrients. Then we buy fertiliser somewhere else. That is not smart infrastructure. That is a design mistake we have normalised.

The technology to do this better is already here. Urine-diverting toilets, source separation, container-based sanitation, urine stabilisation, ammonia sanitation, nutrient recovery and safe reuse in agriculture. This is not science fiction. It exists. Now it needs to move from pilots, conferences and clever PowerPoints into real infrastructure at a bigger scale.

Sanitation is not only about removing waste. It is nutrient management, water protection, soil regeneration, local fertiliser production and public health. Hell, everything is connected. Fish do not want our nitrogen in rivers. Soil does. The future of sanitation is not just better toilets. It is building circular nutrient systems that work every single day. And honestly, we should have started yesterday.