The exact type of final treatment will vary depending on location.
In soft water areas, the disinfected water may be artificially hardened.
In areas with very hard water, the disinfected water is sometimes artificially softened, though this process is going out of fashion.
In areas with a high level of pesticides in the water or where chlorination creates an unacceptably high level of chlorinated organic matter, the activated carbon process may be used to reduce the amount of organic mater (chlorinated and otherwise) in the water that is sent to the consumer.