CT Basement Systems Radon Blog by Matthew A. Bednarz V.P.

Manganese in well water

Posted by Matthew Bednarz on Thu, Dec, 04, 2014 @ 11:12 AM
remove manganese from well water
Manganese in well water is oftentimes mistaken for iron.  It is not uncommon to find an elevated level of manganese in conjunction with an objectionable level of iron in the same water supply.  Although possible, it is not common to find an elevated level of manganese by itself in a private well water supply.
manganese and iron out of faucet resized 600
While iron will leave yellow to reddish and brown stains on fixtures; manganese in well water will typically leave a brown to black stain on fixtures.  Manganese in water can also emit a foul smell.  When present in levels exceeding the .05 mg/l limit, manganese can make the water unpalateable.
Manganese is most often found in a "dissolved" state (manganous), which is clear water manganese.  When oxidation is added via chemical or physical means; the water turns color and the oxidized manganese is (manganic). 
Manganese and iron are the two "stainers" that we typically find in New England well water.  Both have positive charges and are heavy metals. Manganese and iron are governed by EPA secondary water quality standards...which means the standards are based on aesthetic impact and are not health related.  Both leave stains and both can induce an odor in the water supply they're present in.  Manganese removal from water is accomplished by much of the same processess utilized to remove iron from water.
manganese in drinking water
Despite the many similarities between iron and manganese; manganese in well water can be more difficult to remove when compared with iron.  It takes significantly less manganese (.05 mg/l) presence in a water supply to cause problems with staining of fixtures and odor in comparison to iron (.3 mg/l).
 Manganese removal typically requires a significantly higher pH to be efficiently precipitated out of water as compared to iron.  This can potentially translate into more complicated or elaborate treatment schemes such as a
chlorination / filtration system. 
Chlorination Filtration System resized 600
Yet; as is the case with much of water treatment, it depends on the particular water well source to be treated. When the water is acidic, water softeners can prove to be a viable treatment option for manganese since it (manganese) carries a positive charge similar to typical hardness ions in well water.  However; more often than not; effective manganese removal will usually involve some form of oxidation (chemical or physical), followed
 by filtration.  Chemical oxidation is usually done with chlorine or hydrogen peroxide injection.  Physical oxidation is done with air and is oftentimes      accompanied with some form of agitation.
aerator precipitator system resized 600manganese clogged filters resized 600
It is critical to ensure maganese in water levels are within acceptable limits when considering the installation of a reverse osmosis system, ultra violet light, or any other final stage "polisher" filter product.  This is because excess amounts of manganese will quickly foul membranes and carbon filters, or coat UV quartz tubes, requiring them to be replaced prematurely...which increases overall cost per gallon of treated water produced. 

Topics: manganese removal, manganese in well water, brown to black stain