In Germany chlorine is used to treat water in the plant but it's removed before it goes into the pipe. There is a tiny residue but that's residue and not intentional to prevent issues with the pipes.

What does Germany use to manage microorganism growth in it's water distribution system? As I understand cloramine/chlorine is used to keep the small amounts of microorganisms that will always be present in water and pipes from growing into a problem while it travels/sits in the distribution system.

If there is residue of the chlorine then wouldnt there be residue of the harmful compounds it reacts to create?