Abstract: The sewage discharge during the construction of railway tunnel affects the environment sensitive area, hence, it is necessary to set up a sewage treatment station. Onsite investigation of the construction of tunnel sewage treatment stations is carried out on several projects. Some conclusions are drawn as follows: (1) The diversion of clean water and sewage can be realized in the construction period of the railway tunnel to reduce the discharge of sewage and control the construction scale of the tunnel sewage treatment station. (2) On the basis of the engineering measures such as the production of sewage and the diversion of clean water during the construction period and the reduction of the water inflow caused by the tunnel lining and grouting, the sewage treatment scale of the tunnel sewage treatment station can be determined by multiplying the normal water inflow per unit length determined by different geological conditions by the length of the unlined section and the variation coefficient of the water inflow. (3) It is suggested that, on the basis of the charging scope stipulated in the current general (budget) compilation method, the project cost of clean water and sewage diversion, the installation, dismantling and amortization cost of sewage treatment station equipment, and the operation and maintenance cost of sewage treatment station should be included in the estimate.

Key words: railway tunnel, sewage treatment station, scale