Your water lines run underground, so fixing them generally requires exposing the pipes. However–some repairs can be done with trenchless water line excavation, a cutting-edge technique that basically involves running a new pipe through the old one. Trenchless water line repair is a great way to avoid a complete excavation. Here are four methods of trenchless excavation that can be used to repair your water line: Horizontal Boring: also called directional boring, this technique involves using special drilling equipment. A plumbing excavator can dig a new channel for a water line without disturbing the surface of your yard. Trenchless Pipe Bursting: a special tool is threaded within the pipe. As it moves through, it destroys the old pipe, all while running a new pipe behind it. Cure-in-Place: a new pipe covered in an adhesive is inserted into the old one, and then expanded. Once the adhesive (typically a type of resin) dries, the pipe is bonded to the old one. Point Repair: a small hole in the ground is dug, right where the repair is needed. This avoids having the entire pipe being excavated.