BUT that it hadn't always been like that.
If it hasn't always been this way, there may be a leak in the municipal system. Ask the water department to come take a sample and test it. If it's from a municipal leak they should be able to tell from the amount of fluoride. A lot of MI water has fluoride added and it won't dissipate quickly. I would certainly rule this out before I built a pond based on this water.
I did a couple summers with the local water department during college. We used the fluoride testing a couple times to find and fix problems that we wouldn't have found otherwise.
