So is the water at Santa Monica and Newport --but I used to work for the government agency that treated sewage, and I know where it goes after treatment: in to the ocean off Santa Monica. So, I still wouldn't swim in a port, no matter what the government says.
Countries are different. It’s not the government in charge of the water in Denmark but they check up on the councils that are. Also AFAIK there’s another layer of control with EU standards. If you like bathing you’d miss out applying US standards to the Danish sea water quality control.
Indeed, but besides the EU level / standards, there are still differences in approach by the various EU countries.
F.e. Rijkswaterstaat and the water boards are the water managers in the Netherlands. Among other things, they ensure that there is sufficient water. And that the country is protected against flooding. In addition, provinces and municipalities are also involved in water management.
Rijkswaterstaat and the water boards are both governmental institutes, but at different levels. These regional water authorities, the water boards, are among the oldest forms of local government in the Netherlands, some of them having been founded in the 13th century.
But besides that, the Netherlands need coorperation with among others Germany, Belgium and France. Because if they deposit in the major rivers as the Rhine, Meuse etc. this will end up in the Netherlands.
And according to the official sites of the Dutch gouvernment:
The quality of bathing water is generally good. The provinces designate the official swimming spots in the Netherlands. During the swimming season (from May 1 to October 1), the relevant province checks the water at these swimming spots every 14 days. Is the bathing water not clean and safe enough? Then the province can institute negative swimming advice or a swimming ban.
Mainly because of shipping, swimming in the rivers or in certain places in the sea can be dangerous. For example if you swim in the fairways or do not pay attention to the currents.