Hi I assume we are talking ...

Hi

I assume we are talking potable systems here.

we have numerous systems installed and we do not use a contact tank. The uv should be installed before the chlorine dosing. We dose chlorine or chlorine dioxide up to potable standard. Depending on the pipe work you may need a static mixer inline to help mixing. 

This can then either go straight to service or into a storage tank 

hope this helps 

Kevin