I would dig up the pipe only if it leaks enough to lose alot of water. If it is a small seepage I would let it go until it must be dug up and replaced. Do you have any history on the pipe? Is the leak the same or has it gotten worse? You can email or call me directly at my office mon thru fri 8 to 12 940.665.2258 or mikeotto@ottosdirtservice.com