Ground Rod Question

I want to install a ground rod to connect to my breaker panel but am scared to drive this rod into the ground for fear of hitting something. I have underground utilities and realize I can have them marked by the utility companies but I also have a sprinkler system which of course is PVC. How would I make sure I'm not going to hit something? Any ideas? Thanks, Joe in Texas...

JW wrote:
  Quoted Text Here  
We have Miss Utility to call. It is a local government organization that keeps track of underground utilities. Try calling your local city officials.

  Quoted Text Here  
Doesn't your sprinkler system have a bonded 'wire' on it to locate the underground runs? We had that on our sprinkler system as well as on our nonmetallic gas lines in our previous home! You can check your yellow pages for the free service that the utilities in your state support to do this - here you are subject to massive fines and penalties if you hit anything and didn't have the area you were working in marked before you started - this goes even for things like digging to plant shrubs! If you got it marked first the utility eats the cost of repairs or damage!

JW wrote, wondering if this is really what he meant?
  Quoted Text Here  
Dig down and locate the utilities first. Your sprinkler should be no deeper than 18" your cable and phone 36" and power 48-52" nothing past that. I believe a ground rod needs to be at least 8 foot to do any good. We have a service out here called Underground Alert Service and it's free as long as you give them 48 hours advance notice. Believe me the last thing you want to do is hit a power line. One of my employees did it and it burnt a housedown. Lucky the power was mismarked and the service had to pay for the damage.
Rich