Underground pipes supply water from the city water meter to the house, or, in some cases, to an irrigation system. They also carry waste water from the house to the city sewer. Older homes usually have metal supply and drain pipes, while newer homes have PVC lines. Both types occasionally spring leaks resulting in soggy lawns and, with supply lines, high water bills. Repairing an underground leak is inconvenient, but no more difficult than stopping a leak above ground. The job requires basic plumbing skill and tools found in a moderately equipped do-it-yourselfer's garage.
Cut off the water at the city water meter by twisting the shutoff valve with a water key. Dig a hole that allows easy access to the leaking pipe. Mark a cut line several inches from the leak on each side.
Cut out the leaking section with the reciprocating saw. Measure and cut a piece of PVC 1/2-inch shorter that the leaking section. (reference 1)
Slip a coupling band and neoprene sleeve onto each end of the remaining in-ground pipe. Turn back the ends of the sleeves to expose the molded separator rings. Place the PVC against the rings and roll the neoprene ends onto the PVC.
Slide the coupling bands over the sleeves and tighten the clamps with the screwdriver. Refill the hole, and turn on the water at the meter.