Walk along the discharge pipe starting where it connects at the sump pump and going all the way to where it exits the building. Identify any leaks by looking for water stains or feeling the pipe for water droplets. If needed, fill the sump pump hole with water and turn it on so water flows through the pipe during testing.
Circle all leak locations with a dry erase marker so you can locate them later. Turn the pump off before proceeding with the patch.
Hold a PVC compression fitting up to the pipe centering it over the hole. Draw a line on the pipe where each end of the fitting lays, which is where you must cut the pipe to attach the fitting.
Place a pair of PVC pipe cutters on top of the left line, and cut through the pipe until it breaks in two. Slide the pipe cutters to the marked location on the right side of the PVC hole. Cut through this area as well until the center section containing the hole breaks off. Discard the center damaged section.
Unscrew each end cap from the fitting by turning each one counterclockwise. Slide the caps over each end of the PVC pipe with the rubber side facing the gap.
Slide the center pipe portion of the compression fitting into the gap with the ends over the cut ends of the PVC pipe. Slide each of the fitting end caps back toward the fitting, and screw them tightly clockwise to seal the fitting.
Twist each cap an additional one turn using pliers to ensure a tight seal.