What would make boiled water bitter?

The water in my home is bitter after it is boiled. I have no idea why either. We have only lived here a couple of months now and I noticed one day when boiling water for some tea.

We have had well water for the last 15 years or so and since we have moved we now have municipal water.

At first I thought it was the pots I was using. I tried it in several of them and after boiling the water it became bitter. I went out and bought some new cookware and no change at all. You boil the water it will turn bitter.

My neighbors have told me the same thing when I asked them. They say it had started a few months ago.

I have tried boiling it on the electric stove, electric kettle and even a freaking fire in the backyard. The water simply turns bitter when boiled and only when boiled. Out of the tap it is fine until you boil it.

Anybody heard of this or experienced this before?