Until the end of the nineteenth century—before intensive scientific testing and the slow emergence of a deeper understanding of nature and environmental protection—polluted water was perceived as a matter of course in a further developing world, an inevitable part of progress. Polluted water—which due to industrialization gradually came to characterize all water—was seen almost as a sacrificial offering: a normal development that nobody could or would correct; a price worth paying for general wealth and prosperity. When did perceptions of polluted water change, when was it no longer considered a part of everyday life? And what caused the tide to turn?