Water - needs at least ten minutes of boiling at sea level to kill the evil bugs, more at altitude. All cooking does that, too, so cooking vegies is ok. The 3 minutes will get rid of a lot, but not the nasties. Simply boiling the water and turning it off instantly only kills the germs responsible for minor ailments.
Filtering water doesn't get rid of metals, and leaves a lot of poisons. Filtering is mostly a joke. Bought bottled water has more bacteria in it than tap water in Oz.
Only distilled water has got rid of all the stuff. I buy it here.
Tea is an antibiotic. Hot water doesn't kill the germs, the tea does. Tea also has plenty of fluoride in it for teeth. Many govts are worried about the recent obvious increase in dental caries (especially in kids) with the increase in drinking of bottled water in countries with fluoridation, since it has none, thus defeating the whole purpose. Australia included.
According to info I have seen, many major cities here in China already have drinkable water. HK has for decades. No one trusts this. I don't either. However, if the water was really dangerous, then brushing your teeth in it every day would definitely make you sick, as would drinking ice made from tap water, or eating off ice, such as sushi in restaurants.