GROW: Re-use of treated wastewater for irrigation, groundwater recharge and drinking water: environmental impacts and public perception

Europe has faced severe and prolonged droughts in recent years, for example in 2018, 2020 and 2022. These events resulted in a shortage of drinking, reduced crop yields, degradation of ecosystems, and economic losses. These impacts are expected to increase significantly with global warming. Reuse of treated wastewater can be a solution for this problem. By reusing treated wastewater as a source for water for agriculture, industry, ecology or households, water supply can become more sustainable and secure. Therefore, European policy and research have prioritized water reuse and the reclamation of treated wastewater as essential strategies for building a sustainable water system. Two important barriers are preventing application of re-use of treated wastewater. The first is a lack of knowledge about its environmental impacts. We should investigate which pollutants are present treated wastewater and whether they can end up in groundwater. The second barrier is uncertainty about the willingness of the public to effectively consume crops irrigated with treated wastewater or to thrust drinking water produced from treated wastewater. Public acceptance is only possible if safety can be ensured and scientifically demonstrated and if effective communication strategies are developed. This topic can therefore only be effectively addressed in an interdisciplinary way.
Over the past five years, an interdisciplinary consortium of researchers has set up a field experiment where treated wastewater is used to water crops. They have also developed a methodology to better understand perceptions of consumers towards reuse of treated wastewater. Taking advantage of this experience, our consortium will set up a new field experiment where treated wastewater is stored in the subsurface and used to produce drinking water in times of drought and water scarcity.
We will also use our methodology to understand perceptions on other environmental issues where a more effective communication strategy can lead to more sustainable behavior, such as climate change, food choices, and consumption habits. We will also team up with pilot sites in different European countries to compare our experiences and develop recommendations on a European scale.