Removing Iron From Well Water With A Manganese Greensand Filter

Users of water wells sometimes notice a buildup of rust stains on porcelain fixtures. A reddish copper-colored stain along the path of flowing water may be indicative of excessive iron. Owners of water well systems can reduce the level of iron in well water by installing a manganese greensand filter.

Iron is a common element and is naturally dissolved in groundwater. Although water appears perfectly clear when pumped from a well, the iron content undergoes oxidation when exposed to open air. The outcome of oxidation is similar to the rusting process and causes stains on water fixtures. Although not usually a health concern, you may detect a metallic taste to your water.   

A manganese greensand filtration system oxidizes the iron content in water and then filters out the solid particles. The filter is placed on your incoming water line. The typical manganese greensand system consists of two separate tanks. One tank adds a chemical solution to oxidize the iron, and the second tank catches the solid particles in a specialized filter.  

Adding an oxidative solution

An oxidative solution such as potassium permanganate is mixed with the incoming water supply. The oxidative solution reacts with the iron content in the water to create solid particles. Potassium permanganate is a compound of potassium and manganese, and it is continuously added to the flow of water ahead of the filter.

Catching iron in the filter

Water containing the oxidized iron flows through a canister filter containing manganese greensand. At that point, the iron content is essentially rust particles and is trapped within the filter. Greensand is a natural sedimentary material. Greensand is coated with manganese to produce the effective iron filter. Once the system is installed, it requires relatively little maintenance.

Minimal upkeep

Because the filter traps solid iron particles, it must be periodically cleaned through a process referred to as backwashing. The backwash water is drained out through an attached drain as wastewater. The potassium permanganate used as the oxidative solution is replenished when the supply tank is low in volume.

Excessive iron in water may lead to problems worse than porcelain stains. A buildup of iron deposits can occur in appliances such as a water heater. Unexpected stains on washed clothing may be another indicator of excessive iron in a well water system.

When your water filter system is installed, you may prefer to include a bypass valve so that untreated water is diverted to uses where iron is not an issue. Contact a specialist in water filter services (such as one from Friot's Water Treatment CO) for more information about removing the excessive iron from your water supply.