Manganese is a naturally occurring element found in rock, soil,
water, and air. It is an essential nutrient for all forms of
life. The primary source of manganese for most people is food.
Daily intake typically ranges between 1,000 and 10,000
micrograms (μg) per day. There is no federal regulation for
concentrations of manganese in drinking water for health
reasons. However, there is a federal secondary standard of 50
ppb (ppb = μg/L) based on aesthetic considerations such as taste
and color. The EPA recommends that infants under six months of
age and people with liver disease not consume water with more
than 300 ppb for more than 10 consecutive days. A recent
research article has suggested a possible link between manganese
in drinking water and the impairment of intelligence in school-
age children. The levels at which impacts on IQ were seen are
higher than those routinely observed in Madison tap water.
Nevertheless, the Water Utility will continue its efforts aimed
at lowering the amount of manganese in Mad