Some time ago an article by William Warner discussed the influence of religion on wastewater treatment. The article described by means of examples how religious beliefs can direct behaviour relating to health and hygiene. The author stated that the number of people infected by faecal-related diseases continues to grow and he asked if hygiene is controlled better under the myths of religion than the facts of science. His own answer was: probably not - but he added that if all religions commanded: wash your hands after being in the toilet such a single disciplining taboo would have a major positive impact. This paper discusses the role of Professional Ethics in Water Management.