2017 Volume 5 Issue 1 Pages 298-304
Minami-Gamo Wastewater Treatment Plant (MGWTTP) is the most important facility for the Sendai City sewerage system. The plant treats about 70 percent of the municipal wastewater from Sendai City. On March 11th, 2011, the plant was devastated by the Great East Japan Earthquake and the ensuing tsunami. Its foundation was heavily damaged. Sedimentation and aeration tanks were bent. Most of the mechanical and electrical equipment became flooded by seawater and were washed away. MGWTTP completely lost its wastewater treatment function. Due to this damage, the Sendai City Government decided that MGWTTP could not be repaired and instead should be rebuilt as a brand-new wastewater treatment plant (WTTP). In order to maintain a sanitary environment in Sendai during the construction of the new WTTP, a temporary municipal wastewater treatment was required to meet the effluent standard BOD of 60 mg/l as proposed by the National Sewerage Disaster Countermeasures Committee of the Ministry of Land, Infrastructure, Transport and Tourism. Therefore, the government implemented a mid-level treatment employing a contact oxidation with string media. MGWTTP became the largest WTTP that adopted this method in Japan. Operating the mid-level treatment facility, the new MGWTTP was completed five years after the Great East Japan Earthquake. In this paper, the process until the completion of the new MGWTTP is outlined. The Sendai Declaration of Sewerage Works Disaster Risk Reduction, which was adopted at the 2015 Sendai Symposium, is also introduced.
