SUMMARY: On June 21, 2004, the Research and Special Programs Administration¿s Office of Pipeline Safety (RSPA/OPS) issued Advisory Bulletin ADB¿04¿01 to owners and operators of gas and hazardous liquid pipelines to consider the hazards associated with pipeline de-watering operations. This advisory bulletin was originally issued jointly with the Department of Labor¿s Occupational Safety and Health Administration (OSHA) as Safety and Health Information Bulletin SHIB 06¿21¿2004. Operators are strongly encouraged to follow the recommended work practices and guidelines to reduce the potential for unexpected separation of temporary de-watering pipes.