The municipalities are responsible for inspecting bathing water in Denmark and they publish the current bathing water quality on their websites. More or less all Danish beaches have high-quality bathing water. However, pollution such as algae and wastewater can spoil beaches, either permanently or for short periods.
Bathing water is regulated by the Statutory Order on Bathing Water and Bathing Beaches. The regulations apply for beaches on the coast and by lakes. Artificial lakes which are cut off from surface water and the groundwater are not subject to the Statutory Order on Bathing Water and Bathing Beaches.
It is advisable to take basic safety precautions when bathing, see the Danish national water safety tips and more on badesikkerhed.dk