Ensuring that computers are properly grounded is highly recommended. There have been cases in user homes where machines experienced random failures when plugged into power receptacles that had open grounds (i.e. no ground wire at all). This can cause random failures on any computer system, whether it uses ZFS or not.
Power should also have be relatively stable
such that large dips in voltages from brownouts are preferable avoided through the use of UPS units or line conditioners.