Transient Age Transport Model

Hi everyone,

I want to calculate the mean water age of the well water in a transient age transport model. The observation point at the same node like the multilayer well calculates a mean local age of a few days, while the other observation points near there show values about some years. Therefore I want to now how to get the right water age of the water pumped out of the multilayer well.
Is it right to divide the Age-mass period budget [m³/d] with the Fluid Period Budget [m³] of the multilayer well to obtain the age [d] of the water pumped out?

Thanks for your help,
Valentin96

Answer from FEFLOW if someone is interested in this topic:

it is not right to divide mean age flux period budget by fluid flux period budget. You can divide mean age flux budget by fluid flux budget for a MLW, in which case you will obtain a flux-averaged mean age (some kind of average of mean ages in the well), similar to the so-called flux-concentration. Since at the well nodes the dispersive part of mean age flux is neglected, you should obtain a pure fluid-flux weighted concentration