Eagle Mine groundwater discharge permit renewed

March 27, 2015

For More Information
Steve Casey, 906-235-5771, caseys@michigan.gov
Brad Wurfel, 517-284-6713, wurfelb@michigan.gov

The DEQ today announced it has approved revisions to the groundwater discharge permit for the Eagle Mine near Marquette.

The permit provides conditions to safeguard all protected uses of groundwater and surface water in the vicinity of the mine.

Revisions made to the permit in response to public comment that are of particular interest include:
• The addition of wastewater influent sampling prior to treatment by the reverse osmosis treatment units. The reverse osmosis influent will be monitored twice each month.
• Provisions for investigating and addressing elevated vanadium concentrations in groundwater, including the installation of additional groundwater monitoring wells.
• A revision to the method for calculating the allowable operational range for specific conductance which is used as a measurement of treatment system effectiveness.
• Effluent monitoring has been increased from monthly to weekly (pH and specific conductance monitoring remain continuous).

In accordance with DEQ’s permitting process, a draft permit was placed on public notice Dec. 3, 2013, and a public hearing was held March 25, 2014. The DEQ prepared a responsiveness summary addressing comments received during the public hearing and comment period, and identifying revisions were made to the permit since the comment period.

Both the permit and the responsiveness summary can be reviewed online at www.michigan.gov/deq/0,4561,7-135-3313_4117-320096--,00.html.