Disaster Waste Incineration
The Great Hanshin-Awaji Earthquake occurred on January 17, 1995. This earthquake was an extremely catastrophic event that produced a significant amount of disaster waste in big cities. The disaster waste was incinerated at makeshift incinerator locations containing some level of infrastructure improvement. Sixteen years later, the Great East Japan Earthquake happened on March 11, 2011, creating a different aspect as a result of the tsunami originating off the pacific coast of Tohoku.
Marine waste was present because of the devastated areas located along the coast. There were also tsunami-related sediments mixed with seawater. Furthermore, the earthquake caused an interregional disaster including the radioactive waste. Most of the impacted areas were small and medium cities. The infrastructure was also different from that of the Great Hanshin-Awaji Earthquake.
Measures have been taken to dispose of the disaster waste generated by March 2014. Consideration is being given on how to approach disaster waste incineration in preparation for the Nankai Trough Earthquake, which is expected to occur in the near future, based on studies of the processes and outcomes of the disaster waste incineration at the makeshift incinerators.
Regarding the response to the disaster waste generated by the Great East Japan Earthquake and future preparations for further potential similar events, we have realized that establishing systematic and strategic guidelines for feasible disaster waste solutions is required in order to examine how much we actually understand about disaster waste and incineration and to plan proper disposal based on the data obtained.
The Great East Japan Earthquake generated more than 30 million tons of disaster waste. With regard to the amount of incineration, about 30 million tons of the disaster waste generated by the earthquake was disposed mostly as expected. About 13% was incinerated at the makeshift incinerators less than two years after incinerator construction. Incineration adhered to environmental criteria including those for the amount of contained radioactive materials. The waste went through a volume reduction and expeditious process. The amount of waste that needed wide area treatment was 650,000 tons, 610,000 tons of which was disposed. The disposal cost of the disaster waste included the cost of transportation, intermediate processing (segregation, crushing and incineration), recycling, and final disposal. A disposal unit cost tends to rise as the waste incinerator rate increases. The average cost for disposal is 41,390 JPY/ton.
The heat volume of the makeshift incineration facilities had to be controlled and monitored. Precautionary action of hard to manage materials for disaster waste disposal was also required because of the waste quality changes caused by rainwater and seawater. An incinerator design was needed that considers maintenance and repair caused by sand and salt infiltration, and also mechanical failure caused by oversized waste. Operational planning for the incinerators was also required. In addition, ensuring a supply of power, recycling discharged water, and securing operating engineers and establishing a framework for operations were also needed. It took four to eleven months (an average of 7.3 months) to begin the trail operation concerning facility construction. Further issues that need to be resolved include efforts to shorten construction period, simplification and quickness of procedures, and evaluation of the living environment.