This dataset has been collected as part of the EU-funded ProjectÔ within WP6 and has been analysed in D6.13 Social Acceptance Studies. The social acceptance research was designed to inform the implementation of the Project Ô water treatment innovations in four countries: Spain, Croatia, Italy, and Israel. Indeed, the data collection undertaken in each of these locations primarily focussed on attitudes toward the technology-based innovations for water treatment being implemented in respondents’ local Project Ô demosite. Further background information was collected through these studies to identify factors affecting social acceptance in each demonstration site’s region. The social acceptance research for the project was designed and implemented by the Institute for Methods Innovation, one of the Project Ô partners, and the Work Package 6 lead. To measure these attitudes, an explainer video of Project Ô’s implementation of innovative water treatment technologies focusing on the project’s innovation work in the respondents’ country was produced. The survey design used in these studies measured key aspects of local views about local Project Ô innovation plans for water reuse, circular water economy, and related issues. To understand their background views relevant to water reuse, respondents were asked about their local water consumption patterns, their perceptions of the local water supply, and their familiarity with water treatment technology. To understand differences in perceptions about environmental factors, respondents were asked to indicate their views related to different aspects of environmental attitudes relevant to water treatment innovations. This is important for clarifying drivers of social acceptance of new water treatment solutions. Finally, to understand the role of trust towards science and technology, scientists and engineers, and the European Commission in social acceptance of Project Ô’s innovation work.