|Ask The Expert: Iron in my water
|Question: Q: What is the best method for removing iron from my well water? Thanks!
Owls Head, Maine
Answer: A: Oftentimes, iron may appear in a soluble (dissolved) or insoluble (precipitated) state in your water. To significantly reduce the iron, you may need to chlorinate—or otherwise oxidize—the iron such that it comes out of solution and is more easily filterable. An oxidizing iron filter is very effective and a local dealer can recommend that for you. If your iron levels in your water aren't too high, a softener will be very effective at removing iron as well. Some suggest that you shouldn't rely on a softener as it tends to foul the ion exchange resins used to reduce unwanted constituents from your water, but others have experienced effective removal without negative side effects on waters with more than 25 ppm of iron using softeners.
If you're looking at a water quality analysis, soluble iron—also referred to as "clear water" iron—will be represented as Fe+2 (ferrous). Insoluble iron—also referred to as "red water" iron—will be represented as Fe+3 (ferric). Because iron can combine with other elements, it also can be present in an organic complex, which can appear as colorless, yellow or brown. A more daunting problem is when iron bacteria may also be present, which can create reddish brown or yellow slime, clog plumbing and cause a nasty odor that's fishy or oily. A rotten egg odor is generally associated with hydrogen sulfide (H2S), which can be associated with sulfate-reducing bacterias (SRBs) and is a whole other issue (see www.dnr.state.wi.us/org/water/dwg/sulferb.pdf).
For more information, see the following pages from the Wisconsin Department of Natural Resources website regarding iron and iron bacteria in drinking water: • www.dnr.state.wi.us/org/water/dwg/iron.htm • www.dnr.state.wi.us/org/water/dwg/febact.htm • www.dnr.state.wi.us/org/water/dwg/bacti.htm
You can also search www.wcponline.com archives by entering "iron" in the FIND box. While not every article will appear as only select ones are included online, you can ask that a copy of any article appearing in WC&P be sent to you through a simple email request that includes your address and/or fax number. No more than two articles per request, please, or there will be a small fee.
PS: John Beauchamp's articles "Ironing It Out (Part 1 and Part 2)" from July and August 1997 were perhaps the most comprehensive in WC&P on this subject in recent years. In discussing this item, he mentioned that he has seen iron significantly reduced with a softener up to 35 ppm and has heard of removal up to 150 ppm without negative consequences to the unit. Such performance, he admits, may be limited by water quality, particularly pH and oxygen levels. Unfortunately, our online archive only goes back through 1998. If you'd like copies of these articles, email back with your address and we'll be happy to send them to you.
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