Contaminant Level (MCL)
Simazine is an organic chemical used as an herbicide to control broad-leafed and grassy weeds. It's used on a wide range of crops and non-crops, according to the World Health Organization: “artichokes, asparagus, berries, broad beans, citrus fruits, coffee, cocoa, hops, [corn], oil palms, olives, orchards, ornamentals, sugar-cane, tea, tree nurseries, turf, and vineyards, as well as in non-crop areas.”
Simazine arrives in drinking water primarily through runoff from its herbicidal uses.
Simazine is not acutely toxic via oral exposure, but the World Health Organization reports that simazine has caused dermatological reactions in factory workers exposed via skin contact. The EPA warns that long term oral exposure could lead to blood issues:
Some people who drink water containing simazine well in excess of the maximum contaminant level [0.004 milligrams per Liter] for many years could experience problems with their blood.
The EPA recommends granular activated carbon (GAC) for the treatment of simazine.
(whole house & well units)