[Surface water pollution and microbiological indicators].

Surface waters must undergo careful quality assessment before being used as drinking water. Contamination with wastewaters, whether treated, untreated or partially treated, is a risk to public health. Most waterborne infections are caused by ingestion of contaminated water, but contact or inhalation also represent a risk. In industrialized countries, epidemic episodes are mainly due to the spread of new agents or newly identified infections (Arcobacter, Norovirus, Cryptosporodium, Giardia, etc.). To determine the microbial quality of water environments, the latest regulations identify three different groups of indicators according to their contaminating role: faecal, processing, and model or index organisms. No single organism is an adequate indicator of the diverse conditions of water environments. Thus, it is necessary to accurately identify specific indicators.