I've just recieved a quick accurate response to a question about a new meeting room circuit. I'll try for two. None of the branch circuits in the building are grounded and I want to ground my new circuits. I've found the main water pipe at it's entrance into the basement. The electric service into the building is located within a foot of this 1 1/2" copper pipe.The service disconnect is grounded to this pipe. I would like to run a #6 copper wire from this pipe above a dropped ceiling to a JB of my circuit about 20 feet away. I'd like to attach the new ground to my new circuit. Is this proper procedure. Thanks again