The sewer system is ancient and poorly designed, combining storm water runoff with sewage in the same piping system.
下水道系统是古代和设计不当，结合雨水径流污水在同一管道系统。
2
Pipe corrosion come mainly from outside -pipe corrosion and corrosive medium transported inside the pipe. Serious inside -pipe corrosion exists in petroleum and sewage transportation piping.
管道腐蚀主要来自管外腐蚀及管内输送的腐蚀介质，输送石油及输送污水的管道内腐蚀更严重。
3
Alternatively, many homes, as well as businesses and hotels, have their wastes carried by water and pressure through a piping system to a sewage treatment facility.