The simple answer: Water pipe is no longer sufficient as a
building's earth ground. Post 1990 code requires other
earthing electrode selected from the list in paragraphs
(A)(2) through (A)(7) so that building earthing is sufficient
and minimally acceptable.

To reply to 'mixed within' inline replies: Yes, many homes
have only water pipes for earthing. Eventually, all that will
be corrected as we slowly upgrade to minimally acceptable
ground standards. Many homes also have two prong wall
receptacles. Is that acceptable today? Of course not. That
also is slowly being corrected.

Meanwhile for both human safety and for something new to
homes (transistor safety), water pipe earthing is no long
sufficient. Homeowner is encouraged to upgrade building
earthing for more than human safety reasons.

Transistor? Show me any IC that does not have transistors?
Furthermore, transistors - discrete parts - are widely used in
most every electronic device. I am responding here to
something that Pop should have obviously known by looking at
the PC board even on a disk drive. He also ignores
unnecessary transistor damage from decades previous. A
solution that begins with sufficient earthing.

No, I have not used resistance and impedance
interchangeably. Mercy! Read what was posted carefully to
appreciate specific references to each. Comprehending
impedance is necessary appreciate electrical concepts in that
fax machine example; why so much unnecessary transistor damage
has occurred for so many decades.

NID contains protection that was once only an arc over
device - gas discharge tube or GDT. Appreciate why earthing
is essential for phone circuits - why GDTs work. If one
thinks any protector blocks or absorbs destructive transients,
then one never learned what effective protection does. NID
does provide effective transistor protection - but only as
good as its earth ground. Where does the human start to
eliminate transistor damage? Earth ground as even
demonstrated in that previous www.tvtower.com citation.

BTW your 600 volt number is an obsolete 1950s standard that
was once 400 to 600 volts. Times and protectors have changed.

I make no assumptions or rationalizations having learned
this stuff decades ago as an engineer and from experience. It
is routine to protect from direct lightning strikes as even
addressed by Bodle and Gresh in their Mar 1961 paper in the
Bell System Technical Journal. And yes, they are discussing
'transistor' protection back then. Their paper even
demonstrates why underground utility wires require properly
earthed service entrance protection.

There was no rationalization. You are apparently having
difficulty even with concepts of impedance verses resistance.
Those who are not familiar also might post:
Oh, gosh, no. Earth ground has almost nothing to do with
the actual protection.
Earthing is THE one essential component that literally every
building protection system requires. Pop: Read highly
regarded application notes from Polyphaser. Does Polyphaser
discuss their product line? Of course not. Polyphaser
discusses THE most critical component in protection - earth
ground:
http://www.polyphaser.com/ppc_ptd_home.aspx

Many science papers dating back even to the 1930s define
effective protection as based upon techniques pioneered by Ben
Franklin in 1752. Was Franklin also rationalizing? Were GE
and Westinghouse researchers rationalizing when their
equipment atop the Empire State Building could suffer about 25
direct strikes annually without damage? What was posted is
well proven science. But many today still remain in denial.
In denial even about what the NEC now demands for earthing a
building only for human safety.

Water pipe earth ground is no longer sufficient as a
building's only earth ground. This also for so many reasons
provided in previous posts. This proven by literally quoting
NEC text. And yet still many will deny what the NEC itself
demands. Water pipe earth ground is no longer sufficient to
earth a building.

Above is about transistor safety. Different from what the
Original Poster asks and what NEC addresses with demands for
supplemental earthing. A water pipe earth ground is no longer
sufficient. Pop, looking forward to questions once you have
learned from Polyphaser's app notes. Yes, those wires atop
telephone poles are little different from radio station
antenna. As the Polyphaser app notes will demonstrate,
underground wires are also at risk. All three connect
directly to transistors inside a building. Transistor
protection is only as effective as its earth ground.

Pop wrote:
Mercy! I'm not quite sure what you're trying to say here, or
what the point of some of the irrelevant URLs/comments might be,
but ... either you need to step back and put your heard around
this again, or seek further education and experience.
You'll probably object to my post here, but it's so typical of
many on this group lately that I just can't hold it in any
longer. Those who have nothing to say, should say exactly that.
Those who do have something to say, should be clear and concise
about it. Rationalization and guessing have no place in the
realm of safety.