Best water?! or worst water installations?

• "One in ten large water installations in Denmark has caused an outbreak of the so-called legionnaire's disease." DR

And what is this wonderful disease? The dictionary says: "Legionnaire's disease (lē'jenârz') , infectious, sometimes fatal, disease characterized by high fever, dry cough, lung congestion, and subsequent..." Read more.

However for "a country with no armed militias, relatively low violent crime rates and no terrorist attacks for many years." This water installation is a great threat. I guess some FOREIGNERS have installed the pipes!