By Karen Mancl
A metallic taste in the water and stains on fixtures and clothing are all signs of iron in well water. While not a health issue, even a small amount of iron can make water unpleasant to use.
Iron is naturally occurring in much of Ohio’s well water. Iron is in the rocks, sands and gravels that rural homeowners drill down to so they can pump up ground water. A confusing array of options awaits those trying to decide how best to remove iron. The best option depends on the amount and chemical form of the iron.
Iron can be in the household plumbing in the form of iron bacteria, that forms a slime layer inside pipes and water tanks. Shock chlorination of the well and plumbing will kill iron bacteria. Unfortunately, the iron bacteria will grow back, so continuing to chlorinate the well every few months to few years will be necessary to keep the nuisance growth under control.
Iron can be colorless and dissolved in water as it first comes out of the tap, because deep in the ground, no oxygen is present and under these conditions, iron easily dissolves in water. The most familiar chemical form of iron are tiny, rust colored particles suspended in water as the dissolved iron is exposed to the air, just as iron or steel starts to rust.
A water test at an independent lab is the first step to finding a solution, as it can reveal how much iron is in a water system, which is important information to have when shopping for water treatment equipment. For small amounts, a water softener can be used to remove iron. For greater amounts an iron filter work best. For large amounts of iron, a chlorinator with a sand filter may be needed to get the job done. For all treatment systems, regular maintenance is required. Some maintenance can be do-it-yourself. For complex systems, a water treatment service can be used to exchange and clean used filters.
To find out more about iron removal, check the OSU Extension Fact Sheet AEX 323 Iron in Drinking Water. It is available on the website for the Soil Environment Technology Learning Lab at SETLL.osu.edu. There you can also find information on water testing and other water treatment equipment.
Karen Mancl is a Professor in the Ohio State University Department of Food, Agricultural & Biological Engineering. This column is provided by the OSU Department of Food, Agricultural and Biological Engineering, OSU Extension, Ohio Agricultural Research & Development Center, and the College of Food, Agricultural and Environmental Sciences. For more information, Mancl can be reached at 614-292-4505 or Mancl.firstname.lastname@example.org.