These tests are for pH, not GH (or KH) so it would be best not to use the term "hard" until we know the GH. The question you need to ask of the water authority is how they are achieving a pH of 9. You should be able to get the GH of the water from them as well. Check if they have a website (Boston certainly should), this info may be there. I know New York City has very soft water, yours may be as well, which means they are adding something to increase the pH [this occurs with my water here] and once we know what it is, we will have a better idea of what if anything may be necessary.