European Week for Waste Reduction: OiEau works to limit water pollution
On the occasion of European Waste Reduction Week, the International Office for Water (OiEau) reiterates its major commitment to the fight against waste, particularly plastic macro-waste and the circular economy, through innovative projects, the activation of stakeholder networks and dedicated training courses.
These actions demonstrate that waste reduction can go hand in hand with the circular economy, industrial innovation and the preservation of water resources.
Limiting macro-waste in sewerage networks
Plastic macro-waste discharged via sewage systems is a significant source of pollution in aquatic environments. In France, between 2,000 and 9,000 tonnes of macro-waste are discharged each year via sewage systems.
Aware of this challenge, OiEau has promoted and supported several structural initiatives.
The REGARD network: a collective lever
The REGARD Network project, co-coordinated by OiEau and CEDRE, with the support of the Loire-Bretagne Water Agency, aims to mobilise local authorities in the Loire-Bretagne basin to prevent and reduce plastic macro-waste in sanitation systems.
The REGARD network has multiple objectives:
- to create a network for the exchange of experiences between local authorities,
- to support concrete actions in the field,
- to produce resources and references (guides, diagnostics, etc.).
OiEau is involved in particular in diagnostics, the creation of tools (web platform, GIS), the coordination of the network, the training of stakeholders and communication around the project.
An initial technical workshop organised in March 2025 in Saumur raised awareness among stakeholders (local authorities, technicians) of the challenges posed by macro-waste in urban networks and strengthened the collaborative dynamic.
A second workshop is planned for March 2026, with feedback from local authorities and the presentation of tools.
A handbook for better understanding waste transfers to aquatic environments
To support its actions, OiEau highlights a handbook on the transfer of waste and plastics into aquatic environments, produced by INBO (International Network of Basin Organisations, for which OiEau provides the Technical Secretariat) with the support of OFB, ISWA and AFD.
This document aims to raise awareness among waste management stakeholders and the general public by providing guidelines and solutions to better identify sources of plastic pollution and limit their impact.
Training for action: dedicated modules
OiEau offers training courses focused on the reuse, recycling and design of waste and effluent treatment systems, for example:
The SN036 course: ‘Reuse of treated wastewater in industry’ provides an understanding of the technical and regulatory issues involved in reuse.
Training course SN026: ‘Technological choices for the design/rehabilitation of an industrial effluent treatment plant’ provides engineers and technicians with the tools to design more sustainable and circular systems.
OiEau benefits from unique teaching facilities and a 360° training programme, enabling the practical application of what is taught.
The ZEUS project: zero liquid discharge in the food industry
Among OiEau's flagship initiatives to reduce liquid waste, the ZEUS(Zero Liquid Discharge Water rEUSe) project, funded by the European Union's LIFE programme, aims to achieve total recycling of water and dissolved compounds in the agri-food industry.
At the MONIN syrup factory in Bourges, technological innovations enable effluent to be separated into three recoverable streams:
- high-quality water (suitable for food contact);
- mineral salts, to regenerate softening resins;
- concentrated organic compounds, which can be used to produce energy (methanisation).
This process aims to reduce water consumption by 68%, with 40,500 m³ of treated wastewater reinjected on site and the remaining waste (5,000 m³) recovered.
OiEau plays a central role: assisting in the creation of an on-site analysis laboratory, training teams, and creating a comprehensive book to disseminate best practices and lessons learned from the project.
The ZEUS demonstrator was inaugurated in October 2024 in Bourges, marking the start of the project's operational phase.
The ultimate ambition is to replicate the model in other agri-food factories in France and Europe.
An OiEau strategy focused on the circular economy and waste reduction
OiEau's projects illustrate a systemic approach:
- Prevention: raising awareness via the REGARD network, distributing a manual on waste transfers.
- Reuse: training in the reuse of treated water (REUT and circular water).
- Recovery: separation and recovery of effluent flows in the case of ZEUS.
These initiatives not only help to limit plastic pollution in aquatic environments, but also promote water conservation, in line with the major European objectives of waste reduction and water sobriety.