Dunka Mine Water Pollution
What are the concerns about the (closed) Dunka mine?
When the Dunka Mine went bankrupt, the Minnesota Department of Natural Resources (DNR) allowed the LTV Steel Mining company to shutter its on-site active water quality treatment facility and rely on “passive” treatment, provided by constructed wetlands, for control of sulfate and toxic metals.
Research by retired chemist Bruce Johnson documented the Dunka mine’s continuing pollution and the role of specific conductance in harming fish and other aquatic life. WaterLegacy requested that MPCA issue a new permit and control Dunka Mine pollution.
The U.S. Environmental Protection Agency (EPA) has also entered into Performance Partnership Agreements with MPCA to make issuance of updated mining water pollution permits, including a new permit for the Dunka Mine, a high priority.
What’s the status of Dunka mine water pollution permits?
Despite advocacy by WaterLegacy and the MPCA’s agreements with EPA, no updated Dunka mine permit has been reissued. There has been no new review of the variance MPCA granted in 2000 to allow the Dunka mine to exceed water pollution limits. In 2015, after WaterLegacy asked EPA to withdraw MPCA’s NPDES permit authority [link to Petition to EPA due to MPCA Failure to Regulate – not drafted yet], WaterLegacy submitted a supplement to the petition to EPA focusing on MPCA’s continuing failure to regulate pollution at the Dunka mine.
What are the benefits from work on Dunka mine pollution?
Bruce Johnson’s research on harm to aquatic life from Dunka Mine pollution was incorporated into the specific conductivity report that he and Maureen Johnson, a retired biologist, prepared in collaboration with WaterLegacy. This report documents the effects of specific conductivity mine pollution on fish and aquatic life in northeastern Minnesota. The Johnsons’ report supported important EPA research on implementing specific conductance limits in Minnesota.