BLUE PLANET Berlin Water Dialogues November 2021 | An Event Recap

An issue of global importance, the potential of water reuse was examined at the latest edition of the “BLUE PLANET Berlin Water Dialogues”. On November 25th, the format was held digitally for the second time, attracting more than 400 global participants from over 40 countries. Over the course of the afternoon, a line-up of international high-level experts presented insightful perspectives on water reuse and challenges that come along with its implementation. During various break-out sessions and panel discussions, participants had the chance to partake in a vital exchange, debate different approaches and network with stakeholders from the global water sector. The BLUE PLANET Berlin Water Dialogues event series is foreseen to continue its success in 2022.

Water reuse – the future of resource management

Julia Braune, Managing Director at German Water Partnership, opened the conference by drawing attention to the importance of international cooperation and the knowledge transfer, both of which are crucial in tackling global challenges such as water scarcity. „Of all the topics the BLUE PLANET Berlin Water Dialogues series has presented in the past, water reuse is probably one of the most controversial. It is a way to deal with drought and scarce water resources. It deserves a closer look – it divides and leads to discussions“, Braune stated. She was followed up by Thomas Stratenwerth, Head of Division of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, who emphasized the growing importance of water reuse in the political arena, which is reflected by increased government spending in new research for innovative technologies and applications, as well as legislative progress on different levels such as the new EU regulation on minimum requirements for water reuse, and the Agenda 2030.

An untapped resource

“Only two percent of treated wastewater is reused in Europe, while ninety percent of the EU population is connected to wastewater treatment plants. Water reuse is still an untapped resource. However, a lot of development is happening, and the water reuse market is growing at a fast pace”, Dr. Marie Raffin, Innovation Engagement Lead at Thames Water and Chair of the Water Reuse Europe Board of Directors, underscored in her keynote speech.

In Europe, the situation is complex due to a high variability of water resources and demand across regions and countries. Therefore, the continent is still trailing behind despite its potential. Dr. Raffin emphasized the growing importance of water reuse, especially since by 2030 50% of EU river basins will be affected by water scarcity. At the same time, Dr. Raffin identified three fundamental challenges that turn out to also be an opportunity to sustainably implement water reuse in Europe: EU-wide common legislations and regulations, public acceptance for reclaimed water and economic attractiveness of reuse practices.

Opportunities in water reuse: the time is now

The first panel shared insights on different perspectives on water reuse practices with representatives from DECHEMA, Oldenburgisch-Ostfriesischer Wasserverband, ESAMUR and SMS Group GmbH in order to shine a light on the various opportunities that lie within reclaimed water. Even though different in background and key interests, the panellists agreed on the rising relevance of the issue across sectors and the great potential within reclaimed water – not only by preserving potable water resources for drinking water purposes, but also by creating an added value through recovered material and residue from wastewater. Another point highlighted was the difference of water reuse needs and practices on an international level. “In Murcia, Water Reuse is not an opportunity, but a necessity”, Pedro Simón, Technical Director at ESAMUR clarified – which also explains why countries such as Spain or Malta are already more advanced in the implementation of water reuse concepts, than, for example, Germany.

Different approaches to Water Reuse

Participants subsequently joined discussions that built upon the theme of opportunities in water reuse in four break-out sessions. They looked at “Innovative German Reuse Projects”, “Industrial Reuse Concepts”, “Water Reuse Cases in Tourism, Rural Development and Agriculture” and “International Reuse Spotlights: Belgium and China”.

One key takeaway was that a legal framework going beyond EU regulations, which could eventually even generate higher public acceptance for reuse practices, would present an opportunity. However, there is only a high application potential for agricultural and urban water reuse. Furthermore, industrial reuse concepts are case dependent and must be implemented under consideration of long-term strategies. Water reuse technologies do not have to be complex for these purposes – there is rather a need for simple, decentralized, and small-scale technologies that adapt to local needs.

Looking beyond borders: overcoming concerns over water reuse by reviewing international best practise examples

Water conflicts will not only become an issue in agricultural and urban irrigation, but also in public water supply and cooling demand for energy and industry. “Extreme conditions in agriculture but also for urban areas will become the new normal. Consequently, we will see a growing conflict over water. We need to rethink our portfolio in water management and certainly water reuse can be an option, an alternative supply to substitute fresh water supplies”, highlighted Prof. Dr. Jörg E. Drewes, Chair of Urban Water Systems Engineering, Technical University of Munich. His keynote initiated the second part of the conference with a focus on challenges of water reuse. With a side note on the new EU regulation 2020/741 on minimum requirements for water reuse, which came into force in 2020, Drewes pointed out important concerns when discussing water reuse, such as pathogens and antibiotic resistance, as well as concerns about microplastics or chemical residues.

Prof. Drewes provided best practice examples where water reuse has been successfully implemented for years: In California, recycled water exceeds the amount of all reused water in Europe combined and ranges from crop irrigation, to ground water recharge, up to even direct potable reuse. In Murcia, Spain, reclaimed water is a corner stone of the economy and the production of agricultural goods. Thus, he stated, water reuse will be a viable option for alternative freshwater supplies with flexible and innovative concepts providing a solution in regions where the water is scarce.

EU Regulation 2020/741: cooperation is key to ensure harmonisation on water reuse practices

The new EU regulation 2020/741 is to be fully implemented by the Member States in 2023, but there are still open questions on how to adapt local conditions to the legal requirements, as sometimes they differ greatly on a national level. This issue was discussed in depth in the second panel discussion of the day, featuring the European Commission, the Umweltbundesamt, the Abwasserverband Braunschweig and Eurecat, the Technology Centre of Catalonia. One major takeaway is that communication and stakeholder involvement is key: this includes engaging with the end-user, but also considering different working cultures and different local standards across the EU. Water reuse has many facets and different specifications depending on the region. While Germany, for example, needs to brush up on its water reuse practices, as well as implement new processes and risk management approaches as soon as possible, Spain is already ahead, practicing water reuse for years. But in Spain legislations need to be adapted following the new EU regulation also. It became apparent that cooperation between regulatory and operational levels is needed from the start in order to ensure a smooth transition in harmonizing water reuse practices across the EU.

Transparency, trust, and time

The following break-out-sessions examined challenges of water reuse, discussed among others in the session “From risks to regulation”. Here, it was concluded, that the time frame for implementing the new EU regulation is tight, especially in Germany where no legal framework is in place yet. The technology, however, is ready. Digitalization can be monumental in implementation, as the session“Can Water Reuse Benefit from Digital Twinning” acknowledged. As a first step, it was concluded, the needs of the owner operator must be identified and understood.

But what about the end-user? The session “Public Acceptance for Water Reuse” found that public acceptance of using recycled water is rising across Europe. Societal norms are also moving in a direction to where the public could accept recycled water for drinking or consumption of food grown from agriculture irrigated with wastewater. Studies have shown that people are more accepting of the reuse concept than previously thought. To be able to fully achieve acceptance, three key pillars were identified: transparency, trust, and time.

Learning from each other: A model partnership between Europe and the United States

Wrapping up an intense afternoon filled with project insights and expert discussions, a closing keynote by Prof. David Sedlak, Professor at UC Berkeley and Director, Berkeley Water Center, University of California provided views on the historical development of water reuse in the west of the United States – which has half a century of experience working on potable water reuse and the use of treated wastewater for crop irrigation.

While US water resource planners originally looked at Europe for solutions to retreat wastewater in the 1970s, they actually adapted the ‘European model’ to their own local needs over the years. It also works vice versa: water utilities in Europe incorporated efforts from the US into their treatment concepts. Prof. Sedlak stressed that the partnership between European and US-American researchers over the years has been impeccable and moreover greatly contributed to the successful and safe implementation of water reuse practices. He also explained how the US went one step further when deciding to develop additional research in the usage of treated wastewater to grow high value crops – successfully. Now that Europe reexamines its policy to support the expansion of water recycling, Prof. Sedlak encourages the continuation of a successful partnership to learn from each other’s experiences. Not only innovative technologies from the US could be adapted to the European situation, but also regulatory frameworks as well as monitoring schemes. 


This virtual afternoon has once again proven that international collaboration is imperative in addressing challenges of the water sector. Water reuse is an issue of global importance that will only increase as water scarcity will indispensably become more relevant during the next decade. It ultimately does not only affect industry or agriculture players, but, in fact, each and every one of us as the end-user. As the conference has shown, many promising projects and technological innovations are already underway. By working together, the international water industry will be able to create a sustainable water strategy for the future.

Watch video recording of the sessions and download the speaker presentations here.

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The next BLUE PLANET event is planned for 2022. Follow our website for updates.