Urine recycling: Closing the loop at the same price

A study commissioned by AWEL shows that decentralized urine processing for fertilizer costs are similar to upgrading existing wastewater treatment plants to reduce phosphorus runoff into Lake Greifen. Urine processing also makes it possible to recover valuable nutrients and use them locally.

Urine recycling: Closing the loop at the same price

October 28, 2026

Converting urine into fertilizer on a decentralized basis is no more expensive than upgrading existing wastewater treatment plants. This is the conclusion of a study commissioned by the Greifensee Regional Wastewater Disposal Steering Group (RAG). Office for Waste, Water, Energy and Air (AWEL), Canton of Zurich written by Hunziker Betatech AG.

The study authors compared scenarios for reducing phosphorus input into the heavily polluted Lake Greifensee. In terms of cost, two scenarios are equally expensive.
1. Upgrade existing wastewater treatment plants so that they eliminate more phosphorus from the wastewater.
2. Increased urine in smaller, decentralized systems, e.g., from VunaNexus AG to process into fertilizer.

In contrast, the second scenario closes loops and makes valuable resources locally available. Long-term planning pays off – solutions already exist.

More information about the study can be found on the AWEL website: https://www.zh.ch/rag