Generally mistaken. See, eg,
https://www.metabunk.org/threads/debunked-shasta-snow-and-water-aluminum-tests.137/
and
https://www.metabunk.org/threads/what-are-the-normal-levels-of-barium-in-soil-and-water.247/
If you've got a specific test in mind, have a search, and then start a new thread if...