Key learnings from four European EcoSites: Spain, Austria, Denmark and Greece show how governance, utilities and cross-sector collaboration can turn waste and wastewater into valuable resources.
The industrial symbiosis expert community in Europe and worldwide is rapidly expanding, generating a growing number of implementation cases and practical experiments in by-product and waste recovery across industries. Sharing knowledge and replicable experiences is therefore essential to accelerate the transition towards circular and resource-efficient systems.
In this context, INSET presents key insights from the EU-funded SYMSITES webinar “Industrial–Urban Symbiosis in Practice: Lessons from Four EcoSites”, held on 29 January, which brought together local authorities, utilities and industry stakeholders to exchange practical experiences in implementing industrial–urban symbiosis (I-US) solutions.
Moving beyond theory, the session showcased real operational cases demonstrating how cities can shift from conventional waste management to a resource management approach, where wastewater, organic waste, energy and materials are treated as interconnected flows within local circular systems.
Four EcoSites, four implementation pathways
Each participating EcoSite illustrated a different entry point into industrial–urban symbiosis.
In Spain, partners presented the reuse of treated wastewater for industrial and agricultural applications, reducing pressure on freshwater resources while creating new value streams for utilities and local businesses.
The Austrian case focused on integrating organic waste treatment, biogas production and water recovery, demonstrating how energy and by-products can be reinjected into local cycles to support both municipal services and agriculture.
In Denmark, the emphasis was on high-quality waste separation and material recovery, considered prerequisites for increasing the value of secondary raw materials and enabling effective industrial partnerships.
Meanwhile, the Greek EcoSite addressed challenges related to material availability and seasonality, highlighting the importance of logistics, planning and flexible sourcing strategies to maintain stable symbiotic exchanges.
From technology to governance
A key message across all cases was that industrial–urban symbiosis is not only a technological challenge. While infrastructure and treatment solutions are essential, success largely depends on governance, coordination and collaboration.
Local authorities and public utilities emerged as critical system integrators, acting as facilitators between industries, infrastructure providers and communities. Their role includes aligning stakeholders, managing investments, and creating the regulatory and organisational conditions needed for resource flows to circulate efficiently.
By openly addressing regulatory constraints, organisational complexity and financial viability, the webinar provided realistic insights into what it takes to move from pilot initiatives to scalable systems.
Towards circular and resilient urban–industrial ecosystems
Overall, SYMSITES demonstrates how wastewater treatment plants and waste facilities can evolve into local circular hubs, generating environmental benefits, cost savings and new economic opportunities.
The experiences shared confirm that industrial–urban symbiosis is replicable across regions, provided that solutions are tailored to local contexts and supported by strong public–private partnerships.
For further insights and detailed information, the presentation slides from the webinar are available below.
