how to purify the water?!
you need to install a little filtration plant at home, it works and purify the water approx 99 percent
boiling will ONLY kill bacteria/viruses
it won't take out any chemicals
the only way to completely purify water is to distill it... but another choice which will help, is a reverse-osmosis water filtering system
Boiling it will sterilize it if that is what your asking.
You need a filter.