Have a couple friends in AZ with wells & they’re from Nebraska & they talk about the poor quality of the AZ water. I believe it even contains low levels of arsenic.
Arsenic is found in most areas of former volcanic activity. Selenium is also found in most of theses areas. Selenium flushes the arsenic from the body, making the arsenic harmless. New Mexico has the highest est amounts of arsenic in the water of all the states in the US, it also has the lowest rate of the bladder cancer that is supposed to be caused by the arsenic.
I know this because, I read it in the Harvard Arsenic study, which was posted on-line in full before it was re-written to fit Democrat purposes.