I have spoken to a German who informed me that the difficulties at public swimming pools relate largely to the arrival of certain newcomers who are adherents to a religion that demands women dress modestly at all times. These zealots take offense that Western Europeans do not share their belief system that was once largely confined to the Arab World. To discourage swimming in public places, such persons literally foul the waters with human waste.
They forgot their history and the high price Europeans had to pay the first time round to get rid of Islam. Very sad.