Home › How it works
The four classes
| Excellent | The strictest standard — consistently very low bacteria counts across four seasons. |
| Good | Meets the standard with a comfortable margin. |
| Sufficient | Meets only the legal minimum. Fine most days; weaker safety margin after rain. |
| Poor | Failed the minimum. Authorities must advise against bathing — or ban it — for the whole season. |
| Not classified | Usually a new or renamed site without four full seasons of data. Not a hidden problem. |
What the rating does not tell you
It is a season-long verdict, not today's reading: a storm or sewage overflow can make any site temporarily unsafe. It says nothing about jellyfish, currents, algae blooms or lifeguards — only sewage-type contamination.
Why we show a five-season track record
A single Excellent year can be luck. The dataset keeps ten seasons per site, so we mark the sites that have held the top rating five seasons running, the ones that slipped to Poor recently, and the 619 that genuinely cleaned up. That history is the part official portals hide behind a click.
Where the data comes from
All classifications come from the European Environment Agency's official Bathing Water Directive dataset — the 2025 season assessment, the latest published. Re-used under the EEA standard re-use policy, refreshed when a new assessment is released.