ok i'm trying to post again and we'll see what happens.
lynn,
in your link that you posted they show an example of a house with multiple ground rods. they made a mistake in my opinion as they didn't tie these ground rods together in the soil with copper wire. problems do arise when they aren't tied and could even lead to electric shock or damage to tvs, refrigerators, etc. in a worst case scenario. i used #6 on mine, but thicker would've been better because of galvanic reactions to the wire. rust in laymens terms. this also needs to be solid and not multistranded. it is also good to know that when having 2 or more grounds that are in the soil and seperated by distance that these galvanic reactions from the soil could and usually do set up small electric generations much like that of a battery. most soils are acid and small differences set up this phenomena. this could also create what is known as a ground loop that has to do with high frequency ac and can wreck havoc with some radios and tvs with interference.
another thing about that wire connection in the soil between the ground rods is that it adds more contact area to the soil reducing the resistance to the earth and means that a strike is more apt to dissipate better as i'm sure you are very aware in your use of a spiderweb arrangement. this wire could be placed shallowly, but i recommend at least a foot or more down preventing accidentally cutting the wire through gardening or other type mishaps like driving in a mail box post. i actually read somewhere that the 8ft ground really doesn't meet nec standards due to ground resistivity and its limited contact area with the soil. i lost the website long ago in a computer crash, but if memory serves me i think it needed to be 18ft long to meet it for average soils and many don't have average soil. i don't think they forced it beyond 8ft because of difficulties in driving the rods in. hasn't anybody ever thought how they ground a skyscraper? it's definitely not with an 8ft ground rod.
btw one last note on the tying together of these rods is to keep it at least a foot away from your home and never try to put it under or through your home like under basements or crawl spaces as this would bring lightning into the house. no shortcuts and no sharp turns in the wire. also lynn, don't think i'm talking down to you as i'm trying to talk to others simultaneously to inform them what you and i may already know.