I was curious if it is possible to change the pH of water in the presence of an electric field. Specifically if a submerged well pump with an AC motor is improperly wired and there there is a circuit to the iron well casing then is it possible that the pH could be lowered? I have recently replaced a pump. The original pump had exposed wiring and the water was acidic. This caused corrosion of the copper pipes and associated blue-green staining. Having recently replaced the pump and properly wired it, the staining appears to be disappearing. This observation is the motivation for the question.

AC would have no effect as polarity changes 60 times a second. More likely Dielectric issues with non compatible metals. BTW, most well installers don't use Copper due to acidic water. CPVC or PEX is much better and no dielectric issues.