A recent Harvard study draws attention to hard water which contains toxic minerals that can create a dangerous buildup inside the body if consumed for a longer period of time. Millions have improper tap water caused by poor and aging water & pipe infrastructure.
Most, of age, people that have topped up the kettle or perhaps a clothes iron probably will have eventually seen the mineral buildup on the metal parts of the kettle or iron. To remedy that mineralisation requires using filtered town water all the time when filling them up.
According to the above website, the same goes for using filtered town water for making drinks (tea, coffee, chocolate, water bottle), so as to not eventually impair our urinary tract, prostate for men, etc.