Austria topped the rankings with a 95.8% rating, while Switzerland placed fourteenth with 83.1%, illustrating the varying quality of bathing waters across Europe.

According to the EEA's findings, only two locations in Germany—Diethe-Langern and Achterdieksee—were identified as having inadequate water quality.

The European Environment Agency (EEA) publishes an annual report at the start of the bathing season, focusing on water contamination levels, particularly harmful bacteria like fecal enterococci and Escherichia coli, which pose health risks to humans.

In a recent assessment, Germany ranked eighth among 29 surveyed countries, with 90.5% of its nearly 2,300 bathing sites receiving an excellent water quality rating.

The Niedersachsen State Health Office confirmed that the water quality at Diethe-Langern has deteriorated since the early 2020s, indicating ongoing concerns.

Sascha Maier, a water expert, recommends monitoring for signs of pathogens, such as dead fish or visible cyanobacteria, which can indicate potential health risks.

Blue-green algae, which are actually cyanobacteria, can cause skin irritation and produce toxins that are particularly dangerous if ingested, especially for pets.

EEA Executive Director Leena Yl8-Mononen expressed satisfaction with the cleanliness of most bathing waters but stressed the importance of ongoing efforts to improve water quality and resilience against climate change.

The report also indicates that coastal waters generally have better quality than rivers and lakes, benefiting from natural self-cleaning through tidal movements.

In contrast, Albania performed poorly with only 16% of its bathing sites achieving 'excellent' status, making it the lowest-rated country in the survey.

The overall quality of bathing water in Europe has significantly improved over the decades, largely due to EU regulations that have made many previously polluted urban waters safe for swimming.

Despite the overall positive results, five bathing sites were rated as 'good', with two of them downgraded from 'excellent' ratings from the previous year.