Abstract: An improved device (10) is arranged to drill one or more holes through the wall of a subterranean sewer (11). The device includes a frame (13) adapted to be positioned within the sewer and moved to a desired location relative thereto. Three plate-like members (40) are mounted on the frame for movement inwardly and outwardly in a radial direction. An actuator (56) is mounted to the frame, and is selectively operable to move the plate-like members radially outwardly. Each plate-like member carries a motor (18) and a chuck (16) grasping a drill (19). When the motors are energized, the drills rotate. When the actuator is energized, the drills move radially outwardly to bore holes through the conduit wall. The apparatus is used prior to application of grout or sealant in the repair of ground water leaks.