Serving Gogebic, Iron and Ontonagon Counties
Serving Gogebic, Iron and Ontonagon Counties
By TOM LAVENTURE
MERCER, Wis. — A groundwater study of 11 Northwest Wisconsin counties looked at naturally-occurring minerals and raises awareness on the importance of testing unregulated wells.
“It’s important to focus on northwest Wisconsin because there has not been a lot of focus here,” said Kelsey Prihoda, researcher and Great Waters Research Collaborative program manager for the Lake Superior Research Institute at the University of Wisconsin-Superior.
The U.S. Environmental Protection Agency regulates public wells and water systems, and states can also enforce higher standards on disinfection byproducts, metals and inorganic contaminants. But there is virtually no data on 48,000 unregulated private wells in 11 northwest Wisconsin counties. The study creates a snapshot with spikes and patterns for researchers.
“On average, the preliminary results show that Iron County had the highest maximum fluoride and iron levels, and manganese levels were also at or above preventive action limits,” Prihoda said. “The average arsenic concentration was relatively low.”
Aluminum concentrations were relatively low throughout northwest Wisconsin, she said. Lead was at or above preventive action limits, she said.
Approximately 64% of private wells are not using water treatment of any kind, she said. Any home with a well, especially homes with pregnant women, small children, elderly or people with immunocompromised conditions, should be testing water quality annually, she said.
Out of the 704 sample kits for the presence of fluoride and metals distributed through county health departments and UW Extension offices, county fairs and other participating organizations, Iron County was among the top four counties to return the samples picked up in Hurley and Mercer.
“Overall, we’re pretty happy with the representation that we got from the 11 counties,” Prihoda said.
The residents just had to run their tap water long enough to be getting fresh water from the well and not water that had sat in the pipes for any amount of time to avoid external contamination, she said. Other residents tested from the well itself to avoid contamination at all, she said.
Around 50 area residents who picked up test kits last spring in the Mercer area, attended Prihoda’s presentation on the preliminary results of the study on Wednesday, said Teresa Schmidt, director of the Mercer Public Library, where Prihoda gave a presentation on Wednesday. Many were from lake associations and other groups who work on these issues, she said.
They were curious to find out about possible contamination levels and how that might affect the state’s decision for mandatory testing or supplementing fluoride for children growing up in northwest Wisconsin, Schmidt said.
“The health department doesn’t have enough people to do regular testing and so the study had the residents send in the kits giving them a lot more information on the local level,” Schmidt said.
The study measured the levels of fluoride and other naturally occurring metals including arsenic, iron, manganese and aluminum, Prihoda said. Lead was also looked at as a human source contaminant, she said.
Iron and Ashland counties had fairly high averages of fluoride in well water. The 2 milligrams per liter average is enough to require treatment in many cases.
“People should test for fluoride in these counties,” she said.
A fluoride concentration between 0.7 and 1.5 milligrams per liter is essential to building strong bones and teeth in children, she said. If levels are lower than 0.7 mg then it would be necessary to add fluoride treatment, she said.
“That is the sweet spot,” Prihoda said.
Fluoride levels that exceed 1.5 mg and go as high as 4.0 mg can cause dental fluorosis, which damages teeth enamel in children. Levels over 4.0 mg promote dental and skeletal fluorosis, and over 10.0 mg can lead to crippling fluorosis and possibly cancer.
There were some high readings in Iron County that the researchers plan to revisit, she said. But most were in the 2.0 mg range, she said.
Iron County had the highest iron content average of the samples from 11 counties, Prihoda said. This meant it was also not a surprise that manganese levels were also high, she said.
“When this happens it creates a situation that promotes growth of bacteria that is not harmful to health but can make the water smell and taste bad,” she said. “Iron and manganese are not actually toxic but it’s sort of a quality of life issue because of the red or brown staining of the water, which also stains fixtures and clothing and makes it so that people do not want to drink the water.”
Extremely high levels of iron are associated with development of diabetes and cardiovascular disease. Seven of 11 counties had iron concentrations at or above standards, she said.
These levels can be controlled through home water treatment systems or an iron filter alone, she said. The study did not reveal what people with iron and manganese problems are doing, such as buying bottled water to drink, she said.
Arsenic levels in the study were low, which is expected in northwest Wisconsin, but testing wells for the presence of nitrates is important, she said. Where there is agriculture or other land use that lends to toxicity there is a chance for higher arsenic or nitrate levels, she said.
“Nitrates and arsenic are the major concerns for wells,” Prihoda said. “High nitrate levels affect the blood’s ability to carry oxygen and can result in methemoglobinemia and Blue Baby Syndrome.”
Newly constructed wells should test for nitrates every five years when the presence is below 5 mg per liter. This is also recommended if there are pregnant women or infants in the household if levels are between 5 mg and 10 mg per liter.
Private well users should test annually for bacteria including Escherichia coli and total coliform bacteria, she said. Annual testing is recommended when changes are detected in the water quality.
The project was possible with support from the UW System, U.S. Geological Survey, and a $55,626 grant from the Wisconsin Department of Natural Resources through the Groundwater Coordinating Council.
Prihoda said she will apply for another grant to do followup work on areas of concern including in Iron County.
“It was exciting to get citizen-scientists samples from private well owners over such a large area,” Prihoda said. “It provides a better picture of water quality issues and will help with the objective to promote awareness of well water and ground water quality.”
