Had new service put in. The old galvanized rod was about a 1' away from the new one. Electricians just left it in place. I needed to do landscaping so I mearly chopped it off at ground level with a sawzall. Is that sufficient or does it need to be totally removed?

 

I suggest you "Bond" the old GR to the new GR with a bare stranded copper conductor. The Bonding " Jumper and the clamps that bond the conductor to the GR's can be implaced beneath to soil-surface.

The "objective" is to reduce the impedance of the Grounding path; the more metallic Grounding surface in contact with the earth at the depth of moist soil , the better.

 

Does having an unbonded rod so close effect the resistance to earth of my new rod? Is it necessary to remove or bond for this reason?

My reasoning not bonding it was that the old one is galvanized, surely rusted out I imagine after 60 years in service. I doubt its technically "compliant" as a ground rod anyhow.

Also a friend told me some AHJ's don't want two rods despite what it says in the NEC (local codes)... not saying that's an issue here but might be a concern to someone if you simply say 'bond the two'.....

 

You can abandon the old rod as is. It it too close to the new rod to add any additional benefit as it is within the sphere of influence.