I'm sorry about the delay in commenting; there have been a run of emergencies here.
Back in the late 1960s I used to live in a city tower block where the water was ... odd. It was always very hard but the composition varied from day to day; the taste sometimes implied that there might
be some H2
O in the chemical supply, but probably not very much. I know that chemicals were occasionally added to control algae at the reservoir.
My family and I had to use it (and I also breed tropical fish and they just don't survive in water like that,) so I used two different filtering methods. I had a coffee-filter that was like a stainless steel tube with a very fine metal filter-mesh in the end. I packed that with the charcoal that is sold for aquaria. I rinsed the charcoal very, very thoroughly and ran the drinking/washing/livestock water through that.
(The beauty of that is that charcoal adsorbs impurities; later, heating it in the oven releases the impurities and the charcoal is ready to use again. It was a cheap way to do it and, by hindsight, it was environmentally friendly. I was surprised to read on-line that charcoal doesn't adsorb nitrates because it was very good for purifying the water; tea and cooking tasted much better.)
However, the Brita filter cartridges are more efficient and much easier to use. I wasn't sure if they could be obtained in the US, but I found this link - http://www.brita.com/?locale=us
There are filter jugs and filter kettles on sale here and I find the jug is most useful. The filter cartridges seem to take out most of the chemicals and impurities and they are recommended for making a really good cup of tea.
There is only one disadvantage that I know of. The filters really do take the chemicals out so if you start filtering all the drinking and cooking water you may need fluoride toothpaste; there won't be any in the water.
(Incidently, if you ever want to keep rarish fish that need pure water a high percentage of the spawn will hatch in it.)