Water Line Ground Strap?
You might remember the washing machine at the house where you grew up had a green wire running to a clamp on the water line.
Today, the National Electric Code ( NEC ) has strict language for grounding. Today, that ground strap connected to the water line might still be OK - but it can't be just ANY water line. It has to be a metal cold water supply line that comes into the building from underground where it is buried for at least ten feet. The strap must be secured in an approved manner to the water line very close to where the water line enters the building from underground.
In addition, the washing machine outlet must be a three-prong outlet which is properly grounded. And, GFI ciruits are required when electrical outlets are near a water source.
Always check the National Electric Code. Grounding Codes are covered in NEC Article 250.