Coldwater bond ?

[Wireworks]

I'm installing a 320amp main service on a residential detached garage. Main house (120' away). Installing 225amp sub panel in main house. Do I need to run cold water bond from 400 amp main panel all the way to main water supply of main house ?
225 amp subpanel will be externally mounted on main house, will install ground rod for subpanel . Or can I just take coldwater bond to sub panel ?

 

[david]

Of the two ways this is commonly done you can bond the water system to the service disconnect (neutral) at the house if you ran service entrance conductors from the meter at the garage.

If you ran a 4 wire feeder from the service panel at the garage to a main distribution panel at the house you can bond the water pipe to the equipment ground bus at your main panel located at the dwelling

Either way the bonding of the water system can be done at the dwelling location