Iron, Manganese and Corrosion in Groundwater Supplies
Why these two topics belong together
Both are consequences of the same fact: groundwater has been in contact with rock in the absence
of oxygen, so it arrives chemically reduced. That means dissolved metals it would not hold
if it were aerated, and an oxygen and carbon dioxide balance that determines whether it attacks
the pipes carrying it. Neither is a pathogen problem, and both generate more customer complaints
than anything else a well system operator deals with.
Iron and manganese - dissolved at the wellhead, visible at the tap
In the reduced conditions of an aquifer, iron exists as ferrous iron and manganese as
manganous manganese, and both are soluble and colourless. Water drawn from the well can
therefore look perfectly clear. On exposure to oxygen or to a chemical oxidant they convert to
ferric