Terry,
I had a mate forever ago and we read that static electricity can be devastating when you use plastic piping so before his shop was finished we hooked up a full length of stormwater pipe which over here is 4 inch but thinner than sewer pipe 4 inch. Hooked up the vac system and fed sawdust into the other end and on the outside of the pipe, guess what the pipe looked like it needed a shave, so we bought a roll of earth wire stranded at that time electrical cable known as 7.029 pre metric. With the wire we rolled it around the stormwater length on a diagonal wrap went through the experiment again earthing the end at the machine which is earthed through the three pin power lead and to either end of the pipe soldering the connections, voila no more peach fuzz. When I lay my own pipe in my workshop I stretched an earth wire through a hole at the machine end and out to my disk sander, lathe other lathe, drill press, Steel Router bench earthing to each machines frame using solderless Ross Courtney crimp circles made for us sparkies because a spark generated inside the bpipe by friction can ignite and cause horrible chaos.
So the moral of the story is for me better sure than sorry OK call it overkill I call it insurance I have seen workshops destroyed by static started fire guess my tech training gave me access to more horror events than you guys.
I know everyone is an expert just saying what and why I did it my way (thanks Frank Sinatra). I also have a book on using stormwater pipe that decries earthing in any way however me and my mate did it when we set up our workshops in the sixties and I have followed this ever since. I was taught to be cautious.
Have success kind regards Peter.