ReNutriWater aimed to advance sustainable water management across the Baltic Sea Region by demonstrating how treated wastewater and its valuable nutrients can be safely and economically reclaimed and reused. By preserving nutrients in reclaimed water, the project sought to combat eutrophication of the Baltic Sea, reduce the need for artificial fertilisers, and support circular solutions for cities, municipalities, utilities, and other stakeholders.

Freshwater scarcity is becoming increasingly urgent due to climate change, population pressure, pollution, and prolonged droughts. That makes innovative water management essential. ReNutriWater has shown how wastewater — after appropriate treatment — can serve as a valuable resource rather than being discharged after a single use. The project focused on closing local water cycles by reclaiming wastewater and utilising retained nutrients for beneficial purposes.

A central environmental challenge in the Baltic Sea Region is eutrophication — nutrient-driven degradation of water quality. By recovering and reusing nutrients such as nitrogen and phosphorus within treated water, the project reduced reliance on artificial fertilisers while curbing nutrient loads entering water bodies.

ReNutriWater was structured around pilot activities in Poland, Finland, Latvia, Lithuania, and Denmark, reflecting varied geographical and operational contexts. These pilots explored methods for:

• ensuring disinfected water is safe for reuse,
• tailoring reclaimed water composition for specific applications,
• and testing real world use cases, including irrigation and greenhouse cultivation.

By collecting data from these varied environments, the project generated evidence based insights for cities, utilities, and rural practitioners on how to plan, manage, and scale water reuse solutions.

Key Outcomes and Tools

The project delivered a portfolio of outputs designed to support practitioners, policymakers and utilities in implementing water reuse:

• Handbook on Water Reuse –this comprehensive guide presents best practices from ReNutriWater pilot tests, risk assessment guidance, legal considerations, decision support via the WaterSafe IT Tool, and strategies for stakeholder engagement. It is aimed at municipalities, industries, researchers, and water professionals seeking practical knowledge on sustainable water reuse.
• WaterSafe IT Tool – a digital decision support resource that helps stakeholders evaluate technologies and design safe, fit for purpose water reuse solutions.
• Survey Analysis on Water Awareness – undertaken to assess and expand understanding of water reuse opportunities, barriers and stakeholder needs across the region.
• Safe Water Mentoring Programme –this initiative connected participating organisations with experienced mentors to co develop tailored action plans, strengthen technical capacity, and foster sustainable business models for water reuse.

Stakeholder Engagement and Knowledge Transfer

ReNutriWater actively facilitated local and international knowledge exchange through workshops, events and presentations, contributing to broader discussions on water reuse and circular water economies.

A key example was the final project webinar (“Water Reuse and Nutrient Recovery — Results from ReNutriWater”), and the final event (“Water Recycling – Time for a Paradigm Shift”), where experts shared technical findings, pilot experiences, business model perspectives, and strategic guidance for future work in sustainable water management. These events brought together researchers, practitioners, utilities and policymakers to reflect on practical next steps for water reuse in the Baltic Sea Region and beyond.

Additionally, ReNutriWater hosted various local, national and international interactive workshops engaging educational institutions and stakeholders in discussions about public perceptions, technological barriers, and future innovation opportunities.

Relevance and Policy Contribution

ReNutriWater aligns with the EU Strategy for the Baltic Sea Region (EUSBSR), particularly the efforts of Policy Area Nutri and Policy Area Tourism to reduce nutrient pollution and improve water sustainability. Its outputs contribute directly to regional and EU water strategies, including the EU’s broader water agenda, while supporting the achievement of SDG 6 (Clean Water and Sanitation) through innovative, safe, and adaptive approaches to water reuse that strengthen climate-resilient water systems. By coupling scientific insights with stakeholder engagement, practical tools, and strategic guidance, the project has enabled municipalities, utilities, and industries to view water reuse not merely as a technical solution but as a long-term economic, environmental, and social opportunity.

ReNutriWater’s legacy is a stronger foundation for continued innovation, collaboration, and knowledge exchange, helping the Baltic Sea Region move toward resilient water cycles and circular resource use.