How Europe made most, but not all, of its swimming waters ‘excellent’

A new report from the European Environment Agency shows that 96 per cent of Europe's monitored bathing sites met minimum health standards. Even better, around 85 per cent were rated “excellent”, proving that decades of EU environmental regulation are paying off for summer holidaymakers. But don't pack your swim gear just yet. Some 1.5 per cent of monitored waters are still rated “poor”. These sites are plagued by persistent sewage overflows and agricultural runoff, where a dip poses a risk of severe waterborne illness. The EU is trying to tackle these issues, as well as chemical contamination, drought and toxic algal blooms, through stricter legislation and major infrastructure funding, including more than €15 billion for water-system improvements. Through updated chemical rules and the Nitrates Directive, Brussels is targeting major pollutants while enforcing upgrades to municipal treatment plants to remove microplastics and pharmaceuticals.

How are the EU’s waters?

Though overwhelmingly safe, some EU waters remain classified as “poor”, mainly in inland areas of France, the Netherlands and Belgium, where high population density meets intensive agriculture. Safety also varies by water type: coastal seas are best rated, with 88 per cent considered “excellent”, because large water volumes dilute pollution quickly. It's not the same for inland lakes, where the “excellent” figure is 78 per cent. Stagnant waters are prone to nutrient build-up and heat stress. As for EU rivers, only 47 per cent achieved the best rating because they are vulnerable to upstream runoff. Historically, Europe's biggest problem was raw municipal and industrial sewage discharged directly into waterways. In the 1970s, the “sewage era” lasted until the 1990s, mass fish kills and severe bacterial outbreaks were common. Then came the Bathing Water Directive, implemented in 2006, and a huge increase in funding for urban wastewater treatment plants. This has dramatically reduced contamination over the past 30 years. Now, threats to EU waters come from three main sources. The first is agricultural runoff, driven by the overuse of chemical fertilisers, pesticides and animal manure. Rain washes nitrates and phosphorus into streams and lakes, triggering eutrophication: excess nutrients feed toxic cyanobacterial blooms that deplete oxygen and poison swimmers. The second threat is sewage. Older European cities often rely on combined sewer systems that collect both rainwater and domestic waste in the same pipes. Heavy rain quickly overwhelms them. To prevent flooding, they discharge untreated sewage directly into rivers and coastal waters. The third issue is the emergence of chemical contaminants. The current Bathing Water Directive only tests for faecal bacteria such as E. coli and enterococci, failing to screen for chemical contaminants. Yet rivers and groundwater are increasingly contaminated by “forever chemicals” (PFAS), microplastics, heavy metals and pharmaceutical residues. Climate change worsens the situation because warmer temperatures heat the water, accelerating toxic algal blooms. Extreme weather creates a vicious circle in which droughts reduce river volumes, concentrating pollution, before flash floods wash urban and agricultural toxins into swimming areas at once.

The Bathing Water Directive

The Bathing Water Directive protects citizens' health from risks associated with bathing, such as gastrointestinal illnesses. It monitors the quality of coastal, lake and river waters by testing for two faecal bacteria: Escherichia coli and intestinal enterococci. Under the directive, member states define the bathing season, identify and monitor sites, and test each one four times per season for faecal contamination. Based on contamination levels, waters are rated as “excellent”, “good”, “sufficient” or “poor”. Waters aren’t always completely safe because testing is too infrequent. “ if you take a sample, you do your analysis, a couple of days later, you have your results. But people have already swum in that water for weeks. So that is tricky. But doing more frequent monitoring is super costly”, Eline Boelee, expert advisor on water and health at Deltares said. Proactive forecasting can avoid costly reactive monitoring. “At Deltares we also make water quality models which can say, oh, climate change increased temperatures, and this is the impact in the long run, so you need to take measures”, Boelee explained.