Onshore natural gas and hazardous liquid pipeline Natechs in the USA: Analysis of PHMSA incident reports

Natural hazards can be initiating events for accidents in oil and gas pipelines. Severe past incidents bear testimony to the risk associated with pipeline accidents triggered by natural hazards (natechs). Post-incident analysis is a valuable tool for better understanding the causes, dynamics and impacts of such accidents. To identify the main triggers of onshore transmission pipeline natechs in the USA, natural gas and hazardous liquid incident reports collected by the Pipeline and Hazardous Materials Safety Administration were analyzed. Potential natech incidents were identified by automated data-mining followed by expert review. The analysis covered ~21,000 incidents, about 6% of which were identified as natechs. Geological hazards triggered 50% of the identified natechs, followed by meteorological (25%), climatic (11%), and hydrological (11%) hazards. Landslides are the main geological hazard with 43% of the incidents within the category. Among meteorological hazards, lightning is the major hazard with 36%. 84% of the hydrological hazard related natechs were found to be due to floods. Cold-related hazards make up 93% of the natechs caused by adverse climatic conditions. Some preliminary qualitative results on consequences are provided as well.