Colorado has had a problem of PFCs in the water for a couple years at least (that we know of). It’s theorized that the PFCs are coming from the many Colorado military air fields.
Haven’t heard of Dioxin, but PFCs are turning the fish gay.
https:// www.denverpost.com/2016/06/15/colorado-widefield-fountain-security-water-chemicals-toxic-epa/