1. Turn off the water supply to prevent further leakage and drain the affected pipe section. 2. Access the leaking waste pipe by removing any obstructions, possibly including the toilet if necessary. 3. Repairing the leak by tightening joints, replacing damaged seals or washers, sealing joints with plumber’s putty or silicone, or replacing damaged pipe sections. 4. Reinstall any removed fixtures and secure them properly, applying sealant around bases to prevent future leaks. 5. Test the repair by flushing or running water through the pipe and checking for leaks. 6. If the pipe is underground or involves larger pipelines, excavation and more extensive repair techniques such as welding, caulking, and embedding the pipe in concrete may be required. 7. Maintain records of repairs for future reference and monitoring.