I never, in a million years, would have thought that there would be this kind of connection between iron and cancer: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4036554/
My husband and I drink water from a spring on the top of a mountain in the Green Mountain National Forest. I happened to be up there one day collecting the water, as I drive up with our dozen or so bottles to periodically fill, when there was a local guy up there filling his bottles. He said that the water had been tested at some point and found to be completely, 100% pure EXCEPT for having high iron content.
I will be requesting that MSK test my husband's ferritin level. Hope that he has average storage and we can presume that the elevation in the water is not excessive.