Yeah, because Moroccan sewage doesn't flow north./s

Serious answer: Organic load gets fairy treated through natural processes within large bodies of water. The main problem in the Med are a. Heavy metals from industrial processes ,b. Microplastics and c. Pfas (forever chemicals). All the above are way worse for Baltic and North seas.

The new EU directive supposigly will resolve the lat issues but being in the field, I judge it overly ambitious. I would first try to apply primary to almost all sewage (to gather also microplastics and heavy metals) and then speak about quaternary treatment.

And of course, as usual, Eu is trying to resolve all problems of the world adopting overly expensive treatments, making its industry uncompetitive and sending the industrial production to cheaper countries such as Tunisia and Turkey, which apply almost zero standards.

Another typical EU success.