WATER - Quality_Index_2017

Summary based on water analyses carried out between February 2014 and August 2016, on the 36 568 municipalities in metropolitan France, published on the [site of the Ministry of Health] (http://social-sante.gouv.fr/sante-et-environnement/eaux/article/qualite-de-l-eau-potable), for 50 contaminants and physico-chemical parameters. The criteria studied are classified by regulation into two groups of different importance: * **Quality limits** are the most important criteria, for which non-compliance with standards can be dangerous to health, depending on the level and frequency of exceedance. These include microbiological criteria (Escherichia coli, enterococci) and toxic substances (pesticides, nitrates, lead, nickel, copper, arsenic, chlorinated solvents, etc.). As the criteria are defined as quality limits, we have defined the following assessments: * ‘Good’ water quality: less than 5 % of non-compliant analyses **- > Note: 2** * ‘Satisfactory’ water quality: between 5 % and 25 % of non-compliant analyses **- > Note: 1** * ‘Mediocre’ water quality: between 25 % and 50 % of non-compliant analyses **- > Note: 0** * ‘Poor’ water quality: between 50 % and 75 % of non-compliant analyses **- > Note: -1** * ‘Very poor’ water quality: more than 75 % of non-compliant analyses -> **Note: -2** * **The quality references:** exceedances of these criteria do not have a direct impact on health, but they reflect in particular malfunctions in the treatment to make drinking water (certain microbiological criteria, presence of chlorine or aluminium, cloudy water, etc.). They may also reflect the specific characteristics of the resource used to make drinking water (hard/fresh water, acid water, iron, radioactivity, etc.) which may cause discomfort or inconvenience to the consumer (coloured water, scaling due to limestone water, corrosion of pipes and heating appliances by aggressive water). As the criteria are defined as quality benchmarks, we have defined the following assessments: * ‘Good’ water quality: less than 25 % of non-compliant analyses * ‘Satisfactory’ water quality: between 25 % and 50 % of non-compliant analyses * ‘Mediocre’ water quality: more than 50 % of non-compliant analyses The non-compliances identified in this study fall into four main categories: