If we had a finished basement and the gas line was not exposed, our technician told me that another option would be to ground the black iron pipe from outside the house and burying it eight feet into the ground.
We have a gas water heater. There is a yellow, flexible corrugated gas line coming from our water heater. If you do not have a #6 gauge copper wire connected to the pipes and going into your electrical box or outside your home, your gas line is not grounded.
I wasn’t even sure how to tell if our gas line is grounded.. Find two black iron pipes on either side of the aluminum regulator. Once I knew what I was looking for, I saw many yellow gas lines in the ceiling of our basement