Winterthur plans wastewater plant expansion amid environmental and agricultural debate

The ARA Hard wastewater treatment plant in Winterthur requires an expansion to meet legal requirements for filtering micropollutants, such as traces of medication and hormone-active substances. The upgrade also aims to increase nitrogen elimination and prepare the facility for a growing population.

Martina Blum, head of Technical Services, noted that the expansion has responsibilities beyond local borders, as wastewater flows via the Töss river into the Rhine. To obtain cantonal approval, the project includes compensatory measures for the forest area that must be cleared, such as reforestation on municipal land and ecological enhancements like orchards and hedges.

While the city parliament approved the design and zoning changes with a significant majority, a group of farmers has launched a referendum. Opponents argue that the reforestation will eliminate valuable crop rotation areas and threaten their livelihoods.