Uphold MN Manganese Rule

MANGANESE DRINKING WATER STANDARD retained, with citizen pressure

By the end of the day November 17, 2010, thirty citizens had submitted comments pertaining to proposed changes in Minnesota Department of Health Rules. Of these comments, 28 were citizens opposing the proposed repeal of Health Risk Limits preventing excessive manganese in drinking water.  See the MDH web page.

With staff assurance that the numerical standard would not be repealed in this rulemaking and the corresponding revision of the MDH website made, a hearing on the repeal of the Health Risk Limit for manganese that had been set for December 8, 2010 was canceled.

Comments written by WaterLegacy were circulated to support additional citizen participation.  The Department of Health is now taking a closer look at concerns raised regarding manganese for possible future rrule revisions.

Key Points made in WaterLegacy and other environmental health comments included:
1.    The Health Department should not repeal the manganese Health Risk Limit;
2.    Manganese is dangerous to human health, causing impacts to the nervous system;
3.    Repealing the Health Risk Limit will eliminate an important Rule protecting Minnesota citizens from environmental pollution;
4.    There is a real and present danger of manganese toxicity in drinking water resulting from sulfide mining and processing;
5.    The Health Department should be protecting Minnesotans from industrial pollution, not eliminating standards that would require pollution to be controlled.

Over-exposure to manganese is known to cause Parkinson’s-like symptoms.  A recent National Institutes of Health article published in Environmental Health Perspectives in September, 2010 sent to the Health Department by citizen scientists provides additional evidence supporting the preservation of Minnesota’s 100 ug/L limit on manganese in drinking water. This NIH study found impairment in the IQ of school-age children exposed to manganese from drinking water.  NIH Manganese Drinking Water Study September 2010

Sulfide mining leaches metals into water that are dangerous to human health as well as to the ecosystem.  Among the metals leached by sulfide mining and processing is manganese.  Existing mine tailings at the LTVSMC tailings basin leach manganese above Minnesota’s current Health Risk Limits, and the PolyMet Project anticipates additional manganese seeps and discharge. 

Near Emily, MN, a bulk sample (test mine) manganese-mining project is under way, anticipating  full-production using previously the unproven injection well technology; the mobility of groundwater in this location is a significant feature, suggesting that it will be nearly impossible to sequester any pollution from the operation.

Regulators must require mining companies and all other industrial polluters to comply with water quality standards, rather than repealing or weakening pollution limits adopted to protect human health.