By Shereen Siewert
WAUSAU — A temporary spike in iron and manganese in Wausau’s drinking water does not pose a health risk to residents, according to health officials.
Marathon County Environmental Health and Safety Director Dale Grosskurth said state toxicologists consider manganese at levels above 300 micrograms per liter of water (ug/L) a health risk only in instances of long-term exposure. For iron, there are no health-related concerns, Grosskurth said.
Some Wausau residents have expressed concern over green- or brown-tinged water blamed on a change in clarifiers in the city’s water treatment system. The clarifiers were switched June 14, according to Public Works Director Eric Lindman, leading to increased iron and manganese in the city’s water. During the week the clarifiers were switchd, manganese levels had peaked at 400 ug/L, Grosskurth said, but the city’s water treatment system should now be resolved and the water treatment system is effectively removing manganese down to the 50 ug/L level.
At 50 ug/L, issues of laundry or fixture staining, odor and taste, and safety are resolved within DNR and EPA standards, Grosskurth said.
“Iron does not have any health related concerns and the week-long period when manganese levels were elevated represents a short-term exposure and would not be expected to result in adverse health effects in infants, children, or adults,” Grosskurth said.
A number of residents have taken to Facebook in recent days to post photos of discolored water in bathtubs, swimming pools and drinking glasses. A post in the Facebook group “You know you’re from Wausau if…” showed two photos of a bathtub filled with yellow-green water. The post attracted more than 300 reactions and dozens of comments.
Lindman last week acknowledged that the city is dealing with an ongoing issue regarding the water’s color.
“Wausau has had a slight color in the water for a long time and this is associated with iron and manganese and the treatment process,” Lindman said.
The city uses a patented polymer as part of the treatment process and the remaining iron in the water is typically seen in a white bathtub or toilet bowl, Lindman said. Residents can avoid staining by installing an in-home charcoal filter.