KEETAC Mercury Air Pollution

U.S. Steel proposed to increase production at its Keetac taconite plant by 60 percent. A second taconite processing line will be started and plant production capacity will be increased from 6 million tons per year to 9.6 million tons per year.

Information on the Keetac Expansion is available in the final environmental impact statement.

The Minnesota Pollution Control Agency (MPCA) provided notice on June 2, 2011 that an air emissions permit would be issued. On June 27, 2011, WaterLegacy submitted comments objecting to the increased mercury air emissions allowed by the draft permit and requested both a fact-finding hearing and changes in the permit. The Minnesota Pollution Control Agency Board approved the permit at a public meeting on September 13, 2011.

WaterLegacy’s work

WaterLegacy and other concerned groups highlighted concerns about mercury emissions resulting from the Keetac Expansion:

  • The Keetac air pollution permit would allow increased mercury emissions as a result of modifying and re-activating its idled Phase I indurating furnace to allow for an increase in taconite pellet production by 3.6 million tons per year (MTPY) to a facility-wide potential production level of 9.6 MTPY. The modification also included expansions in mining, ore crushing, concentration, agglomeration, and finished pellet handling to accommodate production from the new indurating furnace.
  • The Keetac air pollution permit would allow up to 75.5 pounds per year of additional mercury emissions into the air. The permit sets an 80 percent mercury reduction “goal” after a year with respect to these emissions, but does not require a step down in the permitted mercury emissions.
  • The Keetac air pollution permit does not require any specific or enforceable offset of the additional mercury emissions from the facility. The failure to provide an offset (comparable reduction of mercury from another mining facility) conflicts with Minnesota’s Statewide Mercury TMDL and Implementation Plan.
  • The Keetac air pollution permit and supporting documents allow studies and potential loopholes as emissions expand, rather than requiring a demonstration of mercury reduction in existing facilities, stating that mercury reduction may not be “achievable.”
  • Mercury is a potent neurotoxic that causes brain damage in the fetus, infants and children as well as in animals at the top of the food chain, like the common loon. Minnesota’s lakes and rivers, especially in Northern Minnesota are already impaired for mercury so that eating fish is dangerous to human health.
Key Documents

WaterLegacy’s advocacy on the Keetac Air Pollution Permit included:

WaterLegacy Comment Letter (June 27, 2011)

WaterLegacy Advocacy to MPCA Board (September 13, 2011)



Ongoing work

Minnesota’s mining sector is projected to increase mercury emissions from 2005 to 2018 by nearly 100 pounds per year. During this period, mining grows from 22 percent to 57 percent of Minnesota’s mercury emissions, increasing the risk of mercury contamination of fish, particularly in Northern Minnesota waters. (Data is from MPCA’s 2009 TMDL Implementation Plan).  The statewide TMCL calls for mercury reductions in every sector, including mining.

WaterLegacy and other stakeholders continue to review how waters in the Lake Superior Basin can be protected from increases in mercury resulting from mining expansions.