Does Chongqing really need to install a water purifier?

It is necessary to install a water purifier to solve the problem of secondary pollution of tap water. After chlorine disinfection, tap water can kill viruses and bacteria, but it can't remove heavy metals and volatile substances. Tap water is vulnerable to secondary pollution after long-distance transportation through pipelines, so tap water is basically boiled before drinking. But boiling can only solve the problem of bacteria, but can't solve the problems of sediment, rust, heavy metals, volatile substances, bacterial carcasses and so on. Moreover, after the tap water is boiled at high temperature, the residual chlorine will produce chloroform, which is a standard carcinogen, so it will only be boiled, and the quality of drinking water will not be fundamentally improved, which will also cause serious hidden dangers to health.