Manganese and water quality
Manganese: Manganese is a transition element which is gray, white or silver in color. It is soft
and ductile if pure but usually occurs in compounds. In natural waters it rarely exceeds 1 mg/L.
At 0.1 mg/L, taste and staining problems may occur. Manganese forms a number of salt
compounds and these compounds can include KMnO4 (potassium permanganate) and 2KMnO3
(potassium manganate). Frequently, manganese salts will occur in association with iron salts.
The primary uses of manganese are in metal alloys, dry cell batteries, and micro-nutrient
Environmental Impact: Manganese is a vital micro-nutrient for both plants and animals. When
not present in sufficient quantities, plants exhibit a yellowing of leaves (chlorosis) or failure of
the leaves to develop properly. Inadequate quantities of manganese in domestic animal food
result in reduced reproduction and deformed or poorly maturing young. In humans, very large
doses of ingested manganese can cause some diseases and liver damage, but these are not known
to occur in the United States. Permanganates have been reported to kill fish in 8 to 18 hours at
concentrations of 2.2 to 4.1 mg/L. Manganese is not known to be a
problem in water consumed by livestock. No specific criterion for manganese has been proposed
for agricultural waters. Consumer complaints arise when high levels of manganese are found in
drinking water or domestic water because of the brownish staining of laundry and objectionable
tastes in beverages which may occur.
Criteria: Water to be used as a domestic water source should contain less than 0.05 mg/L