Regulation of volts coming from the power pedestal?

Does a campground have the ability to fix...:

Generally no, however they can call the power company and request they fix it.

(Some power transformers are multi-tap and the power company will often, at the campground's request, set the output to a slightly higher voltage during the peak season.. When it comes to "off season" and less load.. The voltage climbs too high,, This is not something the CG can fix however as they do not have the key to that box. Only the power company does)