SIWat publication reviews the regulatory framework for reclaimed water use

Freshwater resources are under increasing pressure, and reclaimed water is increasingly being considered as one way to improve water security and resource efficiency. The SIWat project has published a legislative review of the EU regulatory framework together with Finnish and Estonian legislation governing the production and use of reclaimed water derived from municipal wastewater for industrial uses and municipal functions. The review was prepared as part of SIWat’s work on data mapping and regulatory analysis and aims to support stakeholders, including authorities, water utilities and industries, in understanding the regulatory framework and enabling conditions for industrial water reuse in the Baltic Sea region.

The review focuses on legislation, permitting procedures and the regulatory requirements that apply to reclaimed water use. It does not assess treatment technologies or set end-use-specific quality criteria or limit values. The publication also considers future EU legislative developments and potential regulatory changes that may affect future conditions for reclaimed water use.

The publication shows that EU legislation provides harmonised minimum requirements for reclaimed water used in agricultural irrigation through the Water Reuse Regulation (EU) 2020/741. For industrial and municipal non-potable uses, the applicable requirements come from several different legal frameworks, including environmental permitting, industrial emissions legislation, worker and chemical safety rules and, where relevant, drinking water and food hygiene legislation.

The review also compares the regulatory approaches taken in Finland and Estonia. In Finland, reclaimed water is not a stand-alone statutory category, and compliance is determined case by case based on the source water, intended use, exposure pathways and destination. Estonia has incorporated reclaimed water into national legislation, establishing permitting requirements, quality classes, monitoring obligations and risk management procedures.

Alongside Finland and Estonia, the publication reviews legislation and regulatory approaches in Sweden, France, Spain and Singapore, providing comparative examples of how reclaimed water is addressed in different regulatory contexts.

The report concludes that while legislative harmonisation exists for agricultural irrigation, industrial and municipal reuse remains fragmented. It recommends clearer fit-for-purpose pathways for common non-agricultural uses, clearer allocation of responsibilities across the reuse chain, more standardised risk management and monitoring documentation, and clearer pilot-to-scale procedures to improve predictability while keeping safeguards proportionate.

The publication was commissioned as part of the SIWat project and produced through a public procurement process. The main authorship was carried out by Sitowise Ltd, with expert input from Tallinn University of Technology (TalTech).

The publication is available on the SIWat project publications, here.