Code says "where avaialble".. if it is not there, you are not required to add.
I believe before the 2005 code that was the language now it says
All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present
Which means that if it is there it must be used. If it is not there you can put in the minimum of 20 feet of rebar if you desire or a minimum of #4 copper. you could also dig your own trench fill it with concrete and have rebar or #4 in that and you still have a CEE if that is what you really want.
Before this change in wording in 05? many people around here never even heard of CEE. Inspectors were not making us ground rebar because footings were already done before electrician ever gets there and rebar was not available like the wording of 250.50 said. Now because of change in wording it is there and you will use it. They will allow you to install your own CEE if it is not done the first time. I have not had to do this but I believe they want it installed close to where the original footing is installed. You can and I have broken out concrete to access the rebar in the footing but I am not sure it is a good idea for the structural integrity.
As many of you know I am a big supporter of the CEE. This is a section that is interpreted differently in different areas. Around here it is basically ignored even if there is rebar. The reasoning is that the rebar is not available when the EC gets there.
I think that is a bogus interpretation and wish the code would make this a "you shall" deal......
Read 250.50 again it says:
that are present at each building or structure served shall be bonded together
That being said, it would my opinion that if there is a new footing going in, with or without steel, then a CEE needs to be installed.
I would do it regardless of the local rules.[/quote]
There are times when reinforcement is not required in the footing or coated reinforcement is used. I have seen concrete with fiberglass strands mixed in it and it supposedly does not need extra reinforcement.