Observation of quality standards is the prime concern of water producers, but are the quality criteria used by professionals the same as those of consumers? How do consumers perceive the quality of the water distributed to their homes? The main concern of SAGEP, water producer for the City of Paris, is to respond at all times to users' expectations. To answer that requirement, SAGEP launched a consumer study on the reaction to tap water.

Analysis of the perceptions of water quality is presented in this paper. It reveals multiple and singular responses, which themselves depend on personal history and development of the individual concerned. An anthropological approach enables one to gain a grasp of the degree to which the diversity of perception comes into play in the day-to-day practice in the domestic environment of tap water. The example of consumer practice in regard to the type of water drunk demonstrates how custom changes with the context and how each person builds up confidence in tap water.

The complexity of what are a priori trivial uses confirms the need for water producers and distributors to make this reality an integral part of their overall management. They should now take in to account, perhaps in a different way, the consumers' expectations.