The Damage and Recovery Measures of Sewage Treatment Systems Caused by the Great East Japan Earthquake

A large number of sewage facilities were severely damaged by the Great East Japan Earthquake in March 2011, mainly by the tsunami caused by the massive earthquake. At the many sewage treatments, the systems were shut down by the tsunami, numerous building structures were toppled by the wave force of the tsunami and electrical and mechanical machines were damaged by submersion. The many pipelines damaged by liquefaction throughout the region lost their ability to carry sewage as a result of plugging by sand after the occurrence of the earthquake. In order to solve technical problems and quickly restore sewage systems, a technical review committee of experts and specialists was set up to consider ways to prevent damage to sewage systems by earthquakes and tsunami. This Committee analyzed the characteristics of the damage and made four proposals on emergency response, emergency restoration, full-scale restoration, and new policies for tsunami countermeasures.