©2018 Mahoning Valley Water Inc.  IRON      Iron is the earths’ fourth most abundant element and is found, to some extent, in nearly all water supplies.  Levels of iron above 0.3 ppm can cause unsightly, rusty-colored staining in sinks, bathtubs, dishwashers, and other water using appliances and can cause laundry to yellow or stain.  At higher concentrations, an unpleasant, metallic taste may be noticed in drinking water or other beverages made with water.  Iron can also lead to blockage in water pipes.      Rainwater and surface waters contribute to the groundwater supply and collect iron in several ways.  Iron can be picked up by rainwater as it falls to the ground by picking up small quantities of airborne iron oxides from atmospheric dust as it falls.  Rainwater and surface water absorb carbon dioxide increasing the potential for dissolving iron from mineral deposits in the earth as these waters flow to the groundwater table. STATES OF IRON      Soluble Iron—Also called dissolved, clear water, or ferrous iron.  Commonly found in well water supplies.  When the water is first brought to the surface, it is usually clear and colorless.  The iron will remain dissolved in the water until exposed to the air.  After its exposed to the oxygen, the iron begins to oxidize and turns into ferric iron. Because soluble iron is dissolved, it can not be filtered.  Soluble iron is prevalent in well waters in our area.      Oxidized Iron—Also called red water or ferric iron.  Commonly found in surface supplies.  Oxidized iron water is red or yellow when first drawn from the tap.  Red water iron will precipitate and settle to the bottom of a container if enough alkalinity is present.  Oxidized iron can be filtered because it is not dissolved.      Bacterial Iron—Living organisms that feed on iron in the water.  Iron bacteria forms reddish-brown growths which may clog pipes and reduce flow rates. Iron bacteria is visible as growths in the back of the toilet tanks where it is exposed to oxygen.  Common names of iron bacteria are Crenothrix, Gallionella, and Leptothrix. PREFERRED METHODS FOR TREATING IRON      Air Induction—Air Induction systems convert soluble iron to insoluble iron then traps the particulate into a filter.  Backwashing the filter removes the accumulated particulate matter.      Ion Exchange (softening) - For small concentrations of soluble iron.  Softeners will generally remove up to 2.5 ppm of ferrous iron.  The key to removing iron with a softener is to keep the resin as clean as possible because iron can coat the resin beads and interfere or stop the ion exchange process.  This is achieved by making sure the unit backwashes frequently and thoroughly. Timer valves are preferred to demand valves unless set with an override.  The drain line flow control may be increased to the next higher level which will increase the backwash rate.  Using a resin bed cleaner in liquid or powder form will scrub the resins beads clean and using red-out or rust-remover type salts will provide some continuous light resin bead cleaning.      Oxidizing Filter—For medium concentrations of iron (up to 8 ppm).  Oxidizing filters use a base material such as Manganese Greensand that is coated with manganese dioxide.  The manganese dioxide converts the ferrous iron to ferric iron which is trapped in the tank.  The filter needs to be regenerated frequently to remove the trapped iron particles and to regenerate the media.  Potassium permanganate is used to regenerate the filter.    Oxidizing filters may only be used on water with a pH above 6.8. If the pH is below this level, oxidation is inhibited and iron removal will be greatly diminished.      Chemical Feed System—For high concentrations of iron, or if iron bacteria is present.  This system consists of a chemical feed pump that injects chlorine into the water.  From the injection point, the water goes into a 120 gallon retention tank to allow a 20 minute contact time to oxidize the iron and to kill bacteria.  The water from the retention tank then goes through a whole-house carbon filter to remove the chlorine and backwash the oxidized iron from the filter. OTHER TREATMENT OPTIONS      Cartridge Filters—Can be utilized when very small amounts of  insoluble iron is present.  Soluble (dissolved) iron is not filterable by cartridge filters.  Cartridge filters are generally used in conjunction with a softener so that both types of iron, if present, are removed.  Cartridge filters should be 4” filters rated at 20 gpm capacity when used on 3/4” household plumbing lines.  Filters ranging from 20 microns down to 5 microns can be used when a 4” filter housing is employed.      Automatic Backwash Filters—These filters can be used where the insoluble iron is great enough to cause frequent cartridge filter changes (and thus increased cost), or when the simplicity of an automatic filter is desired.  Soluble iron is not filterable by backwashing filters.  Media ranging in filterability from 20 microns down to 5 microns can be used depending upon the size of the iron particulate to be filtered.      Birm Filters—These filters contain a media which converts soluble iron to insoluble iron under certain conditions.  Their advantage is that they do not require any chemicals to regenerate. Unfortunately, in Northeast Ohio and Western Pennsylvania, the preconditions which are required in the influent water are not readily available.