View of the Salmon Trout River. Lundin Mining Corporation, present owner of the Eagle Mine, with permits obtained by former owner Rio Tinto/Kennecott, hopes to mine an ore body below this trout stream for copper and nickel. Treated wastewater is to be discharged into groundwater rather than directly into the surface water of the stream. (Keweenaw Now file photo)
The department prepared the proposed permit after an extensive review of the mine's wastewater treatment system, which began operation in 2011. The new permit includes minor revisions reflecting actual water conditions at the site.
According to Steve Casey, Michigan DEQ Water Resources Division Upper Peninsula District Supervisor, the DEQ has decided to hold a public hearing on the permit "to address public concerns," though the time and place for the hearing are not yet set.
A public comment period on the proposed groundwater discharge permit renewal for the Eagle Mine in Marquette County began on Dec. 3. It has been extended through Dec. 20; but, when the time and place for the hearing are announced, the DEQ will announce a new deadline for public comments, Casey explained.
With the renewed discharge permit, the DEQ is working to address the following local conditions:
- Independent of any activity from the mine, naturally occurring background basicity and concentrations of vanadium in the groundwater exceeded the original permit standards, according to a recent assessment. Revised, site-specific limits for vanadium and pH were established in accordance with the groundwater quality administrative rules. These revised limits account for the naturally occurring conditions.
- A new standard requires monitoring for uranium in the wastewater produced by the mine. If it ever is detected at even a fraction of the safe drinking water standard, the mine must take steps to reduce or eliminate the source of uranium.
Previously, some uranium was discovered in a leak detection sump at the mine, likely originating in rock brought to the mine from another site in the Upper Peninsula. Nearly 70 percent of Upper Peninsula drinking water wells contain detectable levels of uranium. However, the leak detection sump in question produces little water, all of which is treated in the reverse osmosis water treatment plant at the Eagle Mine.*
"It's really clean water," Casey said of the water from that treatment plant.
Additionally, copper and lead levels in one well were higher than the permit allowed on three occasions, but the issue has been resolved. The well was disturbed during construction and has since been reconstructed. In the most recent sample, copper and lead levels were in compliance with the permit.
According to the public notice on this permit, the Eagle Mine proposes to discharge a maximum 504,000 gallons per day (184,000,000 gallons per year) of mine contact water only to the ground and groundwater from their discharge areas located in the NW 1/4 of the NE 1/4 of Section 12, T50N, R29W, Michigamme Township, Marquette County.
Mine contact water consists of mine dewatering water, contact storm water from the main operations area, water from the temporary development rock storage area; with small volumes from the truck wash and the crusher operations.
Public comment on the proposed permit must be received by Jan. 20, 2014, until a new comment deadline is announced.
For more information regarding the proposed permit (permit number GW1810162) or procedures for providing comment or requesting the public hearing, contact the DEQ's Water Resources Division, Permits Section at P.O. Box 30458 in Lansing or at 517-284-5570.
Copies of the permit can be viewed at the Water Resources Division in the Upper Peninsula District Office, 1504 W. Washington St. in Marquette. Contact them by phone at 906-228-4853 or by fax at 906-228-4939.**
* Click here to read our Aug. 4, 2012, article on the water treatment plant at the Eagle Mine.
** The proposed groundwater discharge permit was previously available on line. Keweenaw Now is requesting that the DEQ make it available again on their Web site for the extended comment period.