I am using an existing wire that was used for a dryer. I have changed the breakers to 2-20 amp single pole breakers and am splitting the line to make two 110volt GFI outlets for a whirlpool tub (1 for pump and 1 for heater). I have a red, white, and black wires, however, there is no bare copper wire to gound to. I do have access to a cold water line that I can ground to. Would this be an acceptable form of ground.
Thanks,
rgallrn

If it was Dryer. Old days was 2 hots and a ground.
New Construction and remodel require 4 wire. 2 hots, green for ground, and white for neutral.
Sounds like you have no ground, If you have metal conduit, That was probably where it got its ground.
Not all cold water pipes are grounded.PVC, CPVC could be in the middle and may not be good ground.
If in conduit, Pull white out with white and green attached. You now have the 4 wires.
Make sure black and red are on opposite phase, to keep from overloading neutral.
You should read 220 volts between the 2 breakers. 0 volts means on same phase.
Verify both have 120 volts from ground/Neutral.