German Sewage

When I visited Germany for the first time coming from Amsterdam, I told my friend while walking in Dusseldorf why does it smell like sewage? My friend couldn’t smell the odor although he lived there. 

Now that I live in Berlin, I smell this more often. Especially on warm days.

Doing some research it turned to be a well known problem. One of the main reasons is German water saving habits. Water saving technology is becoming mainstream in every household that Germans now consume much less water (for example modern showerheads insert more air into the water to make you consume less). 

This results in not enough water running through the sewage system to flush all the waste, which results in that smell that gets stronger in summer.

I wonder what’s the effect of this bad smell and the bacteria in the air molecules on people’s health. If by saving more water more people are getting sick, then we need to reconsider this decision.