I just lined my old galvanized 6.25" well casing in a similar way by putting a 4" pvc liner in and grouting the annular space between them. It didnt even have to be dry to do it; the grout sets under water.
I sure would think about something similar here, but you've got a very different situation in many repects.
Can you provide a diagram of the whole system from inlet to outlet?
Last edited by crazyj; 03/05/17 09:05 PM.
