You might want to look at water testing kits available from your local aquarium supply shop that has instructions on use. That will give you a basic water quality test that should prove it safe for fresh-water aquatic life.
If you want to get the next level, contact your water-department in your town / city to find out what kind of kits they use and find out what the tests are that they do to make sure that the water is safe for use. They might even be able to supply you with the company's name that you can purchase from.
Naekid, aquarium supply shop, great suggestion!:beercheer: I have wondered about just setting up a still at my BOL (when I get it) to purify water for use. Maybe boiling to steam and then condensing back to water may be the best way to go to be safe. I am reading Foxfire 1, and the end of the book is about stills, can't wait to get there.