Point 1: the facility waste omitting backwards
    The current waste omitting was installed in the 1990s. At that time the population was small. All the pipe diameter was small for saving, so it met the demands of the waste. But with the growing population, nearly 70000, this pipe obviously cannot meet the demands. More littering waste always stops the pipe. Sometimes the waste comes out to the street.
    The above picture is one entrance of the pipe. It stopped for several days so that the waste water came out the street. The citizens reflected strongly, and then the government opened the pipe to find out it is a plastic bag which stopped it.