With new state health department advisory limits on manganese in drinking water and with notice given Mound last December that its levels were above these limits, the city’s rusty water situation that was formerly just aesthetic inconvenience is now an almost $20 million problem.
With that change in status, though, comes the potential for state funding to fix it.
City officials are requesting that Mound be added to the projects priority list at the state Public Facilities Authority, which maintains a revolving fund for aiding cities and towns with drinking water infrastructure improvements.
The application submitted end of April outlines a potential project in Mound of one new manganese filtration plant plus watermain improvements and the drilling of a third municipal well for a total estimated cost of $19.96 million. It would be just over two years until the new plant comes online.
Officials had met in March this year to discuss options available for fixing the manganese problem after Minnesota Department of Health found elevated levels of the contaminant at both of the city’s wells last December.
Spot testing had revealed manganese levels between .45 mg per liter and .72 mg per liter. Subsequent testing in January and February, by both MDH and the city, then affirmed that these results were not an anomaly. MDH has recently set advisory limits of .30 mg per liter for adults and .10 mg per liter for infants following changes made at the federal level in 2018.
Mound city officials had also in March this year initiated an engineering study, the results of which are due next month. That study will help determine best course of action as well as sharpen the cost estimates for those options.
But a fast-approaching deadline on applying for state aid and a spot on next year’s priority list required the city to give some kind of project outline ahead of the study’s recommendation. Officials had already been preferring the filtration plant option when the engineering study was commissioned, having rejected a full treatment plant as too costly and a system for manganese sequestering as ineffective.
The elevated levels of manganese do not pose an immediate health risk but could lead to health problems in future through continued exposure, said Karla Peterson, supervisor of the Community Public Water Supply Unit at MDH.
According to MDH, extended exposure to high levels of manganese in drinking water has been linked to problems with memory, attention and motor skills. There is no risk associated with using water contaminated in this way for bathing, laundry or cleaning.
The recent testing in Mound is part of MDH’s new line of testing throughout the state of Minnesota. MDH only began to pursue comprehensive, city-by-city testing for manganese last year, although it had updated its health guidance values for manganese in 2018 to match changes made by the federal Environmental Protection Agency.
Because manganese testing is still a new phenomenon, not every city’s wells have yet been tested and comprehensive data for Minnesota is not yet available, but information retrieved from MDH shows that Mound is not alone in having levels of manganese above the new advisory limits.
Testing conducted at wells in Chaska and Waverly have shown that these cities have similar levels to Mound of manganese in their systems, while tests in Montrose turned back readings of more than four times the advisory limit, at 1.4 mg per liter.
“There’s a lot of communities on it and it’s going to continue to grow,” said Mound city engineer Brian Simmons, referring to MDH’s list of those areas with elevated levels of manganese.
HOME TESTING: WHAT TO KNOW
Want to know how the water from your own tap fares?
Or if your water softener is doing much of anything for manganese? Because not all of them do.
MDH has posted to its website a list of local and regional testing labs. It is recommended that those curious just about the level of manganese in their water ask the lab in advance about this kind testing since not all labs are equipped to test for manganese. The list can be found at https://eldo.web.health.state.mn.us/public/accreditedlabs/labsearch.seam
Officials for Mound are not endorsing any one lab but did caution residents who decide to have their own tests done against selecting a lab that is also in the business of selling filters, softeners or other products because of the potential for the lab to offer these as an upsell, even if they’re not needed or are ineffective at removing manganese.
A fact sheet about manganese in drinking water can also be found on MDH’s website at https://www.health.state.mn.us/communities/environment/water/docs/contaminants/mangnsefctsht.pdf.