With the aim of addressing environmental concerns from an applied social psychological perspective, this study explores how regulations aimed at reducing industrial pollution contribute to short-term and long-term changes in social representations. The local river in a Valley characterised by strong interactions between industries and communities was the focus of concern. Three features of the representations were examined: images, emotional experiences and practices. The research followed a multi-method approach, using reports completed by 11-to 14-year-old school pupils and collected in three periods: 1974–1977; 1978–1980; 2007–2009. In the third time period, interviews and surveys were also collected. Textual data underwent lexicometric analyses and qualitative content analyses; quantitative data underwent descriptive and inferential analyses. Results show that effective regulations contributed to positive change in social representations of the river. After 30 years, however, tensions between elements of the representation are present. Images and emotional experiences of the river considerably improved, so much so that the river almost disappears from the focus of attention. Practices however are consistent with old representations of the water as noxious, indicating persistent concerns about potential pollution. Results suggest the desirability of continuing participatory engagement between citizens and local/environmental authorities, not only as new regulations are introduced but also after they have been enacted. Copyright © 2011 John Wiley & Sons, Ltd.