Iron & Manganese Removal

Also see: Iron & Manganese Filter Selection Guide

The best place to start with an iron and manganese problem is to get an accurate water analysis. You can also fill out an online technical request form and one of our water technicians will assist you in finding the best system for your needs.

The maximum contaminant level (MCL) set by USEPA standards is 0.3 ppm, also referred to as 0.3 milligrams per liter of water. In concentrations above 0.3 ppm, iron in water can cause staining of fixtures and porcelain, and ruin laundry. A bittersweet astringent taste is detectable at concentrations above 0.5 ppm by many people.

Manganese is often found with iron, and causes black and tea-colored staining, and asphaltic, oily tastes, above .05 ppm. Some of the same filters used for iron, are used for manganese removal (see Iron and Manganese Filter Selection Guide for more information).

Iron and manganese are often found in a dissolved state in well waters, and the water appears clear when first drawn. Upon exposure to air, or after the addition of oxidants (such as chlorine bleach or ozone), this ferrous iron is oxidized ("rusted") to the ferric state to form insoluble particles. The water then looks orange or yellow, or in the case with manganese, brown or black. This can happen in toilet flush tanks and in the washing machine or dishwasher.

We also frequently find iron that is complexed or "bound up" with organic matter, in organic iron complexes that are dissolved in water. In this case, chlorination or ozone is injected prior to filtration.

Iron is commonly treated with automatic iron filters, which can remove both dissolved and oxidized iron compounds. There are several different types of iron filters used, depending on the type and quantity of iron, and the application. Often these systems are used after the water has been pretreated with aeration, chlorine or ozone.

The role of pH (low pH of less than 7.0 is considered acidic, 7.0 is neutral, over 7.0 is more alkaline) is very important in iron treatment. Generally, if the pH of the water is acidic, it must be corrected with a special type of neutralizing iron filter, or ahead of the iron filtration system. It is usually best to test for pH right at the water source, and not depend on laboratory analysis for pH, since in some cases the pH can raise after sampling, giving false results.

Water softening is sometimes used to remove dissolved iron in low levels (less than 2.0 ppm), although more commonly, we use iron filters in conjunction with water softening if the water is both hard, and high in iron or manganese.

Iron is generally not thought of as toxic, although there are some studies that show liver toxicity to men at low levels.