Pure water is a neutral substance, with a pH of 7. Neutral water found in the U.S. generally has a pH between 6.5 and 8.5. Fresh water sources with a pH below 5 or above 9 are considered unhealthy and unsuitable to sustain plant and animal species. When substances of extreme pH come in contact with living organisms, reactions such as itchy skin and red eyes may occur. Along with manganese, it is fairly common in well water.
Iron poses no health risk to humans, in fact trace concentrations of iron are necessary for humans.
It does however pollute water in terms of taste and color. When iron gets into domestic water supplies it stains laundry, etc. It can also coat pipes and other tubing causing a thin slime to appear over them. Set standard levels of iron differ for certain situations. Water containing this much iron has a bitter or astringent taste.