Asian Network of Major Cities 21 　Best practices

Best Practice

Rehabilitating Aged Sewers: The SPR (Sewage Pipe Renewal) MethodTokyo

Topics

Tokyo's sewers have been constructed for over 120 years, and the total length of sewers past their statutory useful life (50 years) stretches approximately 1,500 kilometers. In addition, the sewers developed in concentration since Japan's period of high economic growth (1960s-1970s) will all be exceeding their useful life in the near future.
As aged sewers are one cause of sagging roads and can adversely affect the lives of local residents, their systematic and efficient renewal is essential. In Tokyo that has achieved a high-level of urbanization, however, it is desirable to avoid inspection and installation of sewers with excavation of roads because these works can cause residents inconvenience.
Measures

We investigate sewers conditions via television camera and construct as necessary based upon the results.
The sewers are rehabilitated by using the SPR (Sewage Pipe Renewal) Method, which lines the interior of the pipes, by spiral winding PVC profile thus allowing effective renewal without digging up the road.

・ The SPR Method allows renewal while letting wastewater run and without digging up the roads.
・ As there is no need to dig up the road, the traditional problems associated with construction such as noise, vibrations, and traffic restrictions can be mitigated.
・ Compared with traditional methods of construction in which roads are dug up, disposal of waste soil is not needed and costs and construction period can be cut.
・ The SPR Method can adapt to a variety of sewage pipe shapes such as circular, rectangular, and etc.

・ We have rehabilitated approximately 360 kilometers since 1986.
・ The SPR method has results of about 33㎞ in foreign countries such as Singapore, North America, and etc.

General Affairs Section, General Affairs Division, Bureau of Sewerage, Tokyo Metropolitan Government
（Tel.）　+81-3-5320-6506
（Mail Address） S4000001@section.metro.tokyo.jp