Results of the first alternative model indicate that the distribution of young water in the upper confined aquifer is substantially different when well-bore leakage at known abandoned wells and test holes is removed from the model and that it is sensitive to the location of leaky well bores, which is generally not known. The animation of CFC-11 concentrations for the first alternative model shows no visual change in CFC-11 concentration near the supply well. However, CFC-11 concentrations continue to increase and radiate out from existing multi-node wells toward other pumping wells.