Technological accidents caused by floods: The case of the Saga prefecture oil spill, Japan 2019

This study investigates an oil spill which involved an ironworks factory in Saga prefecture, during the severe flooding that hit southwestern Japan in late August 2019. The aim of the study is to provide an overview of the accident, highlighting the causes and the consequences of this compound disaster. Furthermore, the study analyses the emergency response and clean-up activities in order to identify lessons learned, and propose recommendations for future flood triggered oil spills. The work presented is based on the integration of information available in newspaper articles, government documents and reports, and data and interviews collected during two field trips in the affected area. The permanence of oil and the strong oil odour in adjacent crops as well as on irrigation canals and citizens' houses was revealed during the first field trip, about one month after the accident. The analysis of the documentation on metal working oil revealed that it might have long-lasting impact in terms of environmental pollution. The presence of oil impacted also the implemented emergency response actions, since vertical evacuation, practiced by many residents during the disaster, actually put many of them in more danger as they ended up trapped in oil-covered floodwaters with strong vapours that were reported to cause nausea and skin irritation. Remarkably, it was also found that a previous oil spill had already occurred at the same site following a severe flooding event, highlighting the need to improve preparedness and develop more effective strategies for accident prevention. Disaster preparedness that specifically considers both the natural hazard and the potential for related technological scenarios should be enhanced, in particular regarding chemical accidents triggered by floods. Japan, as well as other parts of the World, is experiencing stronger rainfall events due to a changing climate leading to unprecedented flooding. Therefore, industry, government and citizens should consider the possibility of an increase of weather-related compound disasters in planning and implementation of climate change adaptation strategies.