Qualité des eaux de baignade en mer en 2021, évolution depuis 2013

• In 2021, 2,061 sea bathing sites are registered in mainland France and in five overseas departments and regions and were subject to health inspections. Among them, 77.8% are classified as "excellent" quality (see methodology), 15.3% as "good" quality, 3.9% as "sufficient" quality, 2.2% as "insufficient" quality, and 0.7% in the "unclassified sites" category, which includes new bathing areas, areas with quality changes, and areas with monitoring gaps.

At the European level, the objective is to have 100% of bathing sites classified as at least "sufficient" quality. In France, this quality criterion is met for 97% of controlled sea bathing sites, matching the European average.

• For all controlled and classified sites, the distribution of sea bathing water quality levels varies significantly across territories. • In Réunion, Corsica, and Occitanie, over 94% of bathing waters are classified as excellent quality, while in French Guiana, no bathing site reaches this level. • A clear north-south divide is observed in mainland France. On the English Channel - North Sea coast, the proportion of sea bathing waters classified as "excellent" quality is lower than elsewhere (28% in Hauts-de-France and 65% in Normandy). Conversely, over 80% of bathing sites on the South Atlantic and Mediterranean coasts are excellent quality. For overseas island departments other than French Guiana, this proportion ranges from 29% in Mayotte to 94% in Réunion. • In Hauts-de-France, Occitanie, Martinique, and Réunion, 100% of sea bathing sites meet at least sufficient quality. For other territories, except French Guiana, this proportion ranges from 93 to 99%.

• In 2021, 45 sites are classified as "insufficient" quality for sea bathing: 30 in mainland France and 15 overseas. • In mainland France, two-thirds of these sites are located in Brittany (10 sites) and Provence-Alpes-Côte d'Azur (9 sites). Overseas, bathing areas in this situation are mainly in Guadeloupe (8 sites) and French Guiana (6 sites). • Mainland France: 1,844 sea bathing sites of which 1,458 excellent quality, 279 good quality, 66 sufficient quality, 30 insufficient quality, and 11 unclassified. • Overseas: 217 sea bathing sites of which 146 excellent quality, 37 good quality, 15 sufficient quality, 15 insufficient quality, and 4 unclassified. • English Channel - North Sea coast: 188 sea bathing sites of which 108 excellent quality, 62 good quality, 14 sufficient quality, 4 insufficient quality, and 0 unclassified. • North Atlantic - Western English Channel coast: 709 sea bathing sites of which 591 excellent quality, 91 good quality, 12 sufficient quality, 12 insufficient quality, and 3 unclassified. • South Atlantic coast: 214 sea bathing sites of which 171 excellent quality, 33 good quality, 5 sufficient quality, 5 insufficient quality, and 0 unclassified. • Mediterranean coast: 733 sea bathing sites of which 588 excellent quality, 93 good quality, 35 sufficient quality, 9 insufficient quality, and 8 unclassified. • Mainland France: 80% excellent quality, 15% good quality, 3.6% sufficient quality, and 1.6% insufficient quality. • Overseas: 69% excellent quality, 17% good quality, 7% sufficient quality, and 7% insufficient quality. • English Channel - North Sea coast: 57% excellent quality, 33% good quality, 7% sufficient quality, and 2.1% insufficient quality. • North Atlantic - Western English Channel coast: 84% excellent quality, 13% good quality, 1.7% sufficient quality, and 1.7% insufficient quality. • South Atlantic coast: 80% excellent quality, 15% good quality, 2.3% sufficient quality, and 2.3% insufficient quality. • Mediterranean coast: 81% excellent quality, 13% good quality, 4.8% sufficient quality, and 1.2% insufficient quality.

• Bathing bans can be temporary (for part of the bathing season or the entire season) or permanent for bathing sites with "insufficient" quality for five consecutive years (with the possibility to reopen if water quality improves following repairs for example) and for bathing areas with definitive closure requests for other reasons (e.g., lack of use, safety concerns, etc.). A recommendation permanently discouraging bathing may also be issued for these sites. A site with insufficient quality at the end of the bathing season will be banned or have a discouraging notice for the next season unless corrective measures are implemented to prevent, reduce, or eliminate pollution sources. Among closure and downgrading causes is always the presence of fecal bacteria in waters, the primary monitoring criterion for bathing. Non-compliance may result from poor wastewater collection and treatment operation, wastewater discharge during heavy rainfall, runoff from coastal watersheds (urban areas and agricultural territories with high livestock concentrations), punctual or diffuse industrial or craft discharges, discharge from marinas or fishing ports, or mooring zones.

• During water sampling operations for analysis, visual inspection of the bathing area environment is conducted to identify possible presence of hydrocarbons or tarry residues, macroalgae, phytoplankton blooms, debris, jellyfish, etc., which may also pose health risks and require adapted management measures. There may therefore be bathing closures for causes other than water quality under the bathing directive. During the 2021 bathing season, 294 sea bathing sites underwent temporary closure for health or preventive reasons. Closure duration ranged from 1 to 8 days. In total, across all sea bathing sites, 565 days of temporary closure occurred during the season. Bathing was permanently banned at 4 sea bathing sites.

• Since the implementation of the urban wastewater treatment directive (1998) and new bathing water quality measurement standards (2013), sea bathing water quality in France has remained stable. Thus, for all controlled and classified sites between 2013 and 2021, it appears that: • The number of controlled and classified sites increased only slightly (2,034 in 2013 versus 2,046 in 2021); • The proportion of sites with "excellent" quality ranges between 78 and 83% over the 2013-2021 period; • The share of "insufficient" quality sites declined by 0.7 points, dropping from 2.9% to 2.2%.

• Methodology • Measurement of bathing water quality was made mandatory by European Directive No. 76/160/CEE, initially, then by Directive 2006/7/CE of February 15, 2006 on the management of bathing water quality. • In France, bathing water quality is subject to health inspection organized by Regional Health Agencies and implemented by municipalities or inter-municipal authorities. This inspection covers all areas: • where bathing is usually practiced by a significant number of swimmers, whether developed or not, in freshwater or seawater, • and which have not been subject to a ban made public. • The method provided by Directive 2006/7/CE to assess bathing water quality entered into force in 2013. Four quality classes are assigned to bathing waters: "insufficient," "sufficient," "good," or "excellent," based on analysis results from the last 4 seasons. Classification is determined according to threshold values set by the directive for Escherichia Coli (E. coli) and intestinal enterococci parameters, whose presence in water may indicate fecal contamination and pathogenic organisms. • Classification of a bathing area is based on a minimum of 16 usable samples. Bathing sites where certain sampling rules are not met are not classified and bear the mention "No classification." These sites are categorized nationally as: • "New bathing zone": new site with fewer than 16 samples collected; • "Quality change zones": site where water quality improved following repairs, with pre-repair samples no longer included in classification calculation; • "Insufficient samples": site where sampling rules were not met (insufficient sample numbers, no pre-season sample, or gap over one month between consecutive samples). • In addition to E. coli and intestinal enterococci monitoring, visual pollution inspection is conducted to detect debris presence (tarry residues, glass, plastic, rubber, etc.). • Other parameters may be monitored: pH, transparency, cyanobacteria, macroalgae and/or phytoplankton, etc. Parameter selection depends on site vulnerability study conclusions or "bathing water profile." • The profile, regularly reexamined, allows: • Identification of factors potentially causing water contamination and posing health risks to swimmers; • Definition of actions to prevent pollution and improve water quality.