The following article is by Jennifer Martin-Romme of the Duluth based Zenith City Weekly
Eight drinking wells in northern St. Louis County were found to contain levels of manganese in excess of up to 47 times the state health limit, according to a January 2009 memo from Barr Engineering, a Minneapolis–based environmental consulting company, to the Minnesota Pollution Control Agency (MPCA) and the state Department of Natural Resources (DNR).
The memo indicates that in December 2008 and January 2009, at the request of the MPCA and the DNR, Barr Engineering, whose clients include the fuel and mining industries, sampled residential wells within a 28–square–mile vicinity of mining waste on the Iron Range.
The company tested 15 wells for various metals. Some, like aluminum and manganese, exceeded standards; others, including arsenic and copper, did not.
Minnesota’s recommended limit for manganese in drinking water is 100 micrograms per liter. The 15 sampled wells ranged from 0.66 to 4,710. The other seven wells that exceeded standards had levels of 284, 432, 578, 583, 603, 654, and 1,400.
Manganese is a naturally occurring mineral, often found in iron deposits and thus a byproduct of extracting iron ore. In small doses, it is an essential dietary nutrient, but exposure to high amounts has been linked to “chronic manganese poisoning” since the 19th century.
A 1989 study of adult subjects by the University of Patras in Greece found that as little as 50 micrograms per liter in drinking water was progressively correlated with cognitive impairment and neurological symptoms resembling Parkinson’s disease.
A study last year at the University of Montreal found a six–point drop in IQ scores among children exposed to less than 400 micrograms per liter. The children’s verbal, visual–spatial, and concept–formation abilities were reduced by “a very big difference.”
Due to the sensitive nature of this situation, the Zenith is withholding the names of the well owners and any information that could be used to identify them, including nearby towns and the name of the mine.
None of the state officials interviewed knows whether anyone has continued to use the affected wells or if they have experienced symptoms of manganese poisoning.
According to Stuart Arkley of the DNR, who was a recipient of the 2009 memo, the first round of well testing was conducted to gather baseline information for environmental review of future mining projects.
The test results will be included in the Environmental Impact Statement for PolyMet, a proposed copper/nickel mine on the Iron Range that is not yet in operation.
Arkley says his task, as a project manager in the DNR’s Environmental Review Unit, was to make sure documentation of the testing was sent to the appropriate technical staff and to relay any questions or concerns back to Barr Engineering, but “not to understand every issue in the documents.”
Barr Engineering is one of PolyMet’s primary contractors. Arkley doesn’t feel it’s a conflict of interest that Barr also conducted these tests because “the documents come here and we have technical staff to review them and ask questions if something doesn’t look right.”
He says the DNR provided no written response to the well test results. “There may have been some questions, but we did not send written comments to Barr. But nor did we provide a written approval of the [2009] memo. I do not recall any issues with the analytical methods used by Barr. Typically, when we have significant comments on a document we will ask for a revised copy that addresses those comments. That was not necessary here.”
The Minnesota Department of Health (MDH) sets the state guideline for manganese, but the agency has no authority to enforce it, according to Pam Shubat and Kate Sande with the Health Risk Assessment Unit.
The 2009 memo does not indicate that anyone at the Department of Health was ever notified about the testing or given the results. Shubat and Sande said they had not seen the memo and are not familiar with its contents.
Even if they had been, the MDH health risk limits for chemicals in drinking water, which the agency is directed by state law to develop, function only as recommendations. The federal Safe Drinking Water Act doesn’t regulate manganese at all.
“We might get involved if there’s an enforcement issue involved,” Shubat says. “If we’re consulted and asked to participate, we might write a letter to someone with a well that needs attention.”
But there’s no regulation of residential drinking wells in Minnesota. “A well owner is responsible for their own well unless there’s contamination [by an outside party], in which case the MPCA may step in.”
Filtering is the best option for decontamination. “Manganese is in the groundwater,” says Shubat. “Once you find it, you would have to filter the water…It might enter from rock or from an industrial source [such as an underground storage tank, in which case the manganese would dissipate]. It won’t disappear if it’s coming from rock.”
Shubat and Sande don’t recall any well advisories on the Iron Range during the time period of the tests. Not having reviewed the data, they declined comment as to whether the levels found might be concerning.
“When we develop a health risk limit,” Shubat says, “we’re saying it’s safe to drink that water. That’s the value people can drink safely. We don’t create an upper limit. There’s only uncertainty above that.”
Generally speaking, MDH’s health risk limits are set protectively low and they are more concerned about high manganese exposure with infants, especially those fed reconstituted formula. “We still believe adults can tolerate higher levels.”
Last year, the agency considered raising the manganese standard to 300, which is the health risk limit set by the federal Environmental Protection Agency (EPA). However, after reviewing the scientific research and in response to public outcry, the recommendation in Minnesota remains 100 micrograms per liter.
“If I were the well owner, I’d probably be concerned,” says Richard Clark, a hydrologist with the MPCA, to whom Barr Engineering’s results were addressed.
However, Clark says his role was purely in the context of environmental review for future mining projects, not epidemiology. “We got a request from individuals in the area to have this done. I think there was general concern they were near [mining waste]. We contacted PolyMet and asked if they’d be interested in doing it.”
All the well owners in the area were contacted and “the ones that allowed [the testing] are the ones shown here.” PolyMet would otherwise have no authority to test residential wells.
“More than likely,” says Clark, “[the manganese levels found] were the result of local conditions around the individual wells [such as well construction, the availability of oxygen, etc.]…I think we looked at the results and decided which were affected and which were likely not affected.”
The MPCA has built additional wells near the mining waste “to more directly monitor the effects.” The results will be included in PolyMet’s Environmental Impact Statement, which is expected to be released this spring.
Clark doesn’t know if the well test results were provided to the Health Department nor whether the well owners have been evaluated for symptoms of manganese poisoning.
He is not aware of any agency policy that would prompt further intervention by the MPCA. “The results were provided to them. An explanation letter was sent by PolyMet’s consultant…In general, yes, [the explanation was provided in plain language].”
The Barr Engineering memo indicates that copies of its lab reports were provided to each well owner, but these reports, which are attached to the memo, are virtually incomprehensible without additional information.
Letters were also sent from PolyMet to the 15 well owners, providing the levels of each chemical tested for and a general description of the applicable standards. However, there is no mention of any potential health effects if those standards are exceeded.
The well with the highest manganese was retested six months later, “because of the values seen,” says Clark. This was due to high values overall, not just manganese.
A September 2009 letter from PolyMet to this well owner is very similar to the first notification letters. “The water in your well did not exceed any primary drinking water standard. However, the manganese content of your water was above the secondary drinking water standard and the [MDH] health risk limit.”
The “secondary drinking water standard” is a non–enforceable guideline from the EPA for “aesthetic effects.” For manganese, it is 50 micrograms per liter, mostly to prevent stains on clothing and household appliances.
A “primary standard” would be legally enforceable, except there is no legally enforceable standard for manganese at all—only the EPA’s guideline of 300 and the Health Department’s recommended level of 100—both of which are well below the levels found in this well.
In January 2009, the sample tested at 4,710; by July, it was down to 1,400. Based on Shubat’s statements, this would suggest the dissipation associated with an external source, rather than from the surrounding bedrock.
“It’s more complex than that,” says Clark. “When you look at some of the other parameters, you get a better picture of where the water from [the waste] is flowing.”
In its 2009 memo, Barr Engineering concluded, “The reason for the highly variable observed manganese concentrations is unknown,” dismissing the possibility that the nearby mine could be related because higher contaminant levels did not directly correlate with each well’s proximity to mining waste.
However, there is a consistent connection when factoring in the type of well in addition to its proximity. The highest manganese levels were found closest to the mine, in wells dug into “glacial drift”—a shallow layer of gravel, sand, or clay, saturated with groundwater.
Of the 15 wells tested, eight are in glacial drift. Only three of those did not exceed manganese limits, but they were either at a distance from the mine and/or separated from it by a body of water. Lower levels were also found closer, but only in wells dug into bedrock.
“I believe [Barr Engineering’s] conclusions make sense,” says Clark. “What’s ultimately going on will come from the monitoring wells. In order to make assessments, you need to look at the parameters…The manganese is subject to local conditions in and around the well. Without knowing more about the well, I can’t hazard a guess.”
St. Louis County no longer offers residential well testing and can only direct inquiries to private labs. More information on wells is available through the Well Management Division of the Health Department, 218–723–4642.
Thanks go to the Zenith City Weekly and to the author Jennifer Martin-Romme for this excellent article, without which we might believe the rhetoric of Minnesota politicians and agencies promoting “Minnesota’s STRONG regulations” for protecting it’s citizens and the world. You can read more or sign up for delivery by subscription at Zenith City Weekly
