At least 4 samples must be taken per bathing season, and the interval between two samples must never exceed one month.
Based on the results of the analyses performed over a four-year period, the bathing water quality is classified as one of the following: poor, sufficient, good and excellent.
The Directive also calls for:
- a visual inspection to detect the presence of tar residue, glass or plastic,
- monitoring of cyanobacteria, macroalgae and phytoplankton and management measures in the event of algae blooms.
However, the presence of the above is not taken into account in the classification.