For me it would be three things:

1: Insufficient bonding of equipment [using only the conduit for grounding in liew of a grounding conductor]. That one has only a few places where it's not bad, but mostly it is a hazard over time.,

2: Allowing [in the past] the use of a Gray conductor for use as an Ungrounded conductor and the stipulation of a "Natural Gray" conductor for the Grounded conductor. This should have never been allowed. I have seen Natural Gray only a few times and under some lighting, it looks the same as any other gray. It should have been reserved for either a grounded conductor [my preference, so it can identify separate multiwire systems in one enclosure], or only an ungrounded conductor - but never both as to the color variant of natural gray.
I've heard some of the home center personnel tell someone that it is a "hot wire" [ungrounded], but never a "neutral" [grounded]. This scares the heck out of me!!,

3: Cold water system for grounding electrode supplemental. This isn't really too bad until it falls into a 1000 amp service being supplemented to a 3/4" water pipe, or it being the sole electrode. Bonding of it is OK [to an extent! too much parallel current flowing in some places]. This whole GES situation is so controversial and mis understood by people that it's difficult to discuss without heated arguments or offending someone accidentally. To me, the worst thing for a lightning discharge grounding system would be to use the local underground water system, since the discharge is commonly connected to anyone's system that has a connection to the pipe. The UFER system to me is a better approach, since it will spread the discharge path locally to only that site.
The problem of paths created on the local utility power distribution is, of course, the key issue of bringing discharges in and out from remote locations, but it's limited to potential by relatively small conductors that do not always run in straight lines. Besides, the most crucial problem exists in the ground it's self prior to the discharge, so setting up a large grid is asking for trouble!

These are just my rant and rave thoughts, so please feel free to comment. If you must flame me, please keep it light! [Linked Image]

Scott.

Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!