This is a existing 200 amp service that had a 1 1/2 metal water pipe that was being used as the grounding electrode with (2)5/8 ground rods with # 6 wire as a supplemental electrode it is a block building with no steel. The water pipe is being replaced with pvc what is required with the GEC now that there is no water pipe only the ground rods that has a side walk over them.
"250.50 Grounding Electrode System. All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used."
Based on the above, the ground rods are it!
You may want to consider checking the integrity of the existing rods. You may also install another of the GEs, and/or check with your local AHJ.
Based on the letter of 250.50, the rods are all that is required, lacking any other available item.
They did put 1 1/2 copper back in to replace the main and extended it 3' above the floor then they replaced the overhead copper with pvc then tied back to the existing copper. I was able to tie back to the main water line that was replaced, now they had 3/0 copper run as the GEC to a buss bar and made taps off of that to a SDS and the main. Off of that tap I need to ground the water pipe that was isolated by the pvc and a copper air compressor line, what size wire is needed.
You use 250.66 to bond water lines. Other piping systems can be bonded with a wire sized to 250.122 and the circuit "likely to energize" the pipe. Typically on things like compressor piping, you could use the EGC to the compressor. (250.104(B))
At my house the shop air line is bonded with a #8 solid but that is what I had handy.