Lino Lakes seeks solutions for high manganese levels in drinking water

The Minnesota Department of Health tested all of the wells in Lino Lakes for manganese levels. The results were received in December 2019. 

LINO LAKES — Following tests of two randomly selected public water wells in the city conducted by the Environmental Protection Agency (EPA), it was determined that some of the city’s wells have high levels of manganese. 

Greg Johnson, of WSB, and Public Services Director Rick DeGardner explained the findings and some possible solutions at the Jan. 6 City Council work session.

“The quality of our water hasn't changed. It has been that way for years and years,” DeGardner said. “This isn't something that is unique to Lino Lakes, it is common throughout the metro area; we just happened to be selected, and some people think that is a bad thing, but I think it is a good thing so we can correct it.”



The EPA sets safe drinking water standards (primary and secondary). Primary standards are regulated through the establishment of maximum contaminate levels (MCL). “The EPA's secondary standards have always been treated as more aesthetic quality issues,” said Brian Norma, Minnesota Department of Health (MDH) field engineer for the Lino Lakes area.

The Safe Drinking Water Act requires that public drinking water supplies be evaluated for the presence of secondary unregulated contaminants every five years. The Unregulated Contaminant Monitoring Rule (UCMR) is used by the EPA to specify no more than 30 unregulated contaminants to be monitored by public water systems during that time period. Public water suppliers are required to test for the possible presence of those contaminants of concern; the data, compiled through a nationwide survey, is useful in developing regulations that protect public health.

“There are dozens of contaminants that we test for, and any contaminants that have a high occurrence or elevated concentrations, that is usually the first step of moving towards a federally enforceable standard, but the process takes a long time to create a MCL,” said Karla Peterson, supervisor of MDH’s  Community Public Water Supply Unit. The latest list of contaminants includes manganese.

Every public water supply system is required to publish its manganese results in a consumer confidence report, which typically comes out in between May and July. “The city is being very proactive in notifying residents before that consumer confidence report (is issued) and working toward solutions,” Peterson said.



The city was randomly selected to be tested in October 2019 and was notified about its manganese levels in November 2019. The test results from MDH concluded that Well No. 3 contains 367 micrograms of manganese per liter of water (µg/L); Well No. 4 contains 82.7 µg/L. A safe level of manganese for an infant is 100µg/L. That level goes up to 300µg/L for children older than 1 and for adults.

“We presented the information to them and they really wanted to be ahead of the curve and say, 'Once this information is released, what potential issues will the customers have?'” Norma said. “They took it a step further and wanted to test their other wells so that they knew where those are at. The city wants to be forthcoming with the information that they have. If they withhold this information, they are not really serving their constituency very really well.”

The test results for all wells came back Dec. 31, 2019. (See the full results in the above graphic.) 


Health effects 

Certain levels of manganese, which is naturally occurring in groundwater, can be useful for the body. However, there is research to suggest that too much of it could be harmful.

Said MDH Toxicologist Helen Goeden, “Young infants tend to absorb higher levels of manganese and they are also less able to get rid of it, so that leads to higher retention in body. When they are exposed to higher levels, that can end up leading to some problems. Health effects that have been seen in toxicity studies show it can cause some neurological or behavioral effects and changes in learning.”

Children and adults who drink water with high levels of manganese for a long time may have problems with memory, attention and motor skills. It is important to note that simply bathing or showering in water with high levels of manganese is not dangerous. Manganese in your water can stain your laundry, cause scaling on your plumbing, and make your water look, smell, or taste bad. Manganese can also create a brownish-black stain on your toilet, shower, bathtub or sink.



The city is looking into both short-term and long-term solutions. Currently, Johnson said the city has already reduced the manganese levels in the water supply by limiting the use of wells with high levels of manganese. That solution will not work, however, during the city’s peak usage during the summer. Since the city is not using all of its wells, current manganese levels are below 300µg/L. It is still recommended that residents consider using bottled water for formula-fed infants under the age of 12 months.

The city is also in the process of sending out letters to households and businesses and will hold a public informational meeting at 6 p.m. Wednesday, Jan. 22. Both city staff and an official from MDH will be present to provide information and answer questions. 

“We are trying to provide as much information as we can to residents so they can be informed and determine what, if any, action should be taken to address the issue,” DeGardner explained. 

Future solutions could include modifying the city’s existing watering ban ordinance, utilizing water from neighboring municipal water systems, drilling new wells or constructing a water treatment plan, which could cost upwards of $20 million, DeGardner said. 

Ultimately, DeGardner said city staff will likely come back to the council to request it authorize WSB to complete a water supply and treatment feasibility study in the future. Mayor Rob Rafferty suggested delaying action on the item until after the informational meeting Jan. 22. 

“I think it is wonderful that we are trying to get ahead of the issue rather than creating an issue,” Rafferty said. “We are not hiding anything. We are trying to address a possible problem.” 

In the meantime, the city encourages residents to stay up to date on the issue by visiting the city’s website at and clicking on the “public water advisory” on the homepage. Concerned residents can filter manganese out of their drinking water by utilizing a variety of products such as a refrigerator water filter or pour-through pitcher. 


Editor Shannon Granholm can be reached at 651-4107-1227 or

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