Iron and manganese are two common contaminants of drinking water in the United States. Neither mineral represents a significant health risk at the levels generally present in water, but they can cause unpleasant aesthetic effects. Water testing and treatment are available if you think excess minerals are in your water.
Mineral Sources
Both iron and manganese are common metals found in soil and rocks. Water dissolves these elements while percolating through the ground, carrying them along as just two of many possible contaminants in groundwater. Deep wells and springs are more likely to have high concentrations of iron and manganese than surface streams or reservoirs. Groundwater pollution can increase the levels of both metals, with rusty pipes an additional possible source of excess iron.
Allowable Levels
The Environmental Protection Agency classifies iron and manganese as secondary water contaminants, meaning they are not considered hazardous to your health at the levels normally found in drinking water. Public water sources are not required to test for the presence of these contaminants, but guidelines are issued by the EPA for use in assessing the aesthetic qualities of the water. Iron's maximum contaminant level is set at 0.3 mg/L, or parts per million, and manganese at 0.05 mg/L.
Iron
Iron levels above 0.3 mg/L in your water can result in red-orange discoloration and a metallic taste, but no adverse health effects at commonly found levels, according to the Pacific Northwest Extension. In fact, about 5 percent of your daily iron requirement is met from drinking water. High iron levels can give coffee, tea and alcoholic drinks a bad taste and cause dark discoloration of cooked vegetables. Bottled water or a variety of in-home water treatment systems are available if you find high iron levels in your water. Simple faucet attachments can be an inexpensive solution if the iron levels aren't too high.
Manganese
Manganese levels over 0.05 mg/L lead to black-brown discoloration and a bitter metallic taste of drinking water. Although not considered a health hazard at levels up to 10 times this high, heavier exposure over a period of years has been associated with nervous system toxicity characterized by abnormal body movements, according to the Connecticut Department of Public Health. Young children and pregnant women should avoid high manganese levels in drinking water, since some baby formulas and dietary supplements include extra manganese. Both in-home water treatment systems and bottled water are options for avoiding high manganese in your water.
What to Do
If you suspect your water has high contaminant levels, the first step is to determine the water source. For public water sources, get in touch with the local water department and ask about contaminant monitoring and testing results. If the local department can't help, contact your state's division that regulates public water quality and compliance for assistance. For private water sources such as wells, look for a certified laboratory that performs drinking water analysis and can guide you through the testing process.
Member Comments