Even small amounts of mercury can have big impacts. Minnesota is a national leader in keeping mercury out of the environment, and was one of the first states to develop a statewide mercury reduction plan.
The MPCA prepared a report that evaluated the sources of mercury and quantified the reductions needed to meet water-quality standards. It includes strategies to keep mercury in water discharges below 24 pounds per year, and mercury air emissions below 789 pounds per year. Learn more:
The MPCA adopted Minn. R. 7007.0502 to accomplish the reductions outlined in the TMDL:
- Mercury reduction plans. Affected facilities must prepare mercury reduction plans.
- Performance standards. Certain facilities are required to meet performance standards for mercury control.
- Emission inventory for mercury. The largest sources of mercury submit an annual mercury emission inventory to the MPCA.
Facilities that are a “mercury source” by definition in the rule and emit more than 3 pounds of mercury (or 5 pounds for industrial boilers) must complete a mercury reduction plan.
Mercury and ferrous mining
Facilities for ferrous mining or processing were required to reduce mercury emissions by 72% from 2008/2010 emission levels by Jan. 1, 2025. In January 2023, after lengthy review and discussions with each taconite facility, MPCA issued deficiency letters to each of the taconite facilities that submitted alternative plans, having found that each facility’s conclusion that a 72% reduction was not technically achievable had not been adequately demonstrated and that their submitted plan was deficient. In these letters, MPCA required that the facilities submit a revised mercury reduction plan by Sept. 2024. MPCA is currently reviewing the revised submittals.
At the federal level, EPA revised the national standards for taconite iron ore processing in 2024, setting a new mercury emissions limit that facilities must meet by March 2027.
- EPA’s new mercury emissions limit represents a reduction of 0-47% for the taconite industry, depending on the individual indurating furnace.
- EPA expects taconite facilities could meet the new limit by using activated carbon injection with high efficiency wet scrubbers.
While the revised federal standards achieve a moderate reduction in mercury emissions, they don’t go far enough for Minnesota to reach its statewide mercury reduction goal. Achieving this goal will require greater reductions, like those contemplated in the state rule, from the taconite mining sector in particular.
To accelerate development of mercury controls at taconite facilities, MPCA sought and received funding in 2023 to find innovative solutions to protect our environment and support Minnesota mining. The funding provides $16.7 million to taconite facilities in the state to support pollution reduction actions and research on mercury emissions, sulfate discharges, and greenhouse gas emissions. The funding is available to taconite facilities through June 2027.
Two facilities submitted plans that meet the emission-reduction requirements:
Two facilities submitted plans with proposed reductions of less than 72%:
Four facilities asserted that no further reductions are technically achievable and submitted alternative plans proposing to conduct further literature and engineering review beginning in mid-2020:
Other sources of mercury
Minnesota facilities with air-quality permits that emit mercury over certain thresholds were also required to submit mercury reduction plans. American Crystal Sugar in East Grand Forks proposed ways to limit mercury emissions from its two boilers to less than 10 pounds per year, to comply with Minnesota rules.
Gerdau Ameristeel, an iron and steel melter, proposed strategies for reducing its mercury emissions to less than 35 milligrams per ton of iron/steel produced, as required by Minnesota rules.
Emissions inventories
Oversight committee updates
In 2008, stakeholders recommended that an oversight group be established to review and evaluate progress toward achieving the goals of the Statewide Mercury TMDL, provide advice to the MPCA on implementation, and determine if additional measures are needed to meet these goals. This group has met annually since 2009.
For more information about the oversight committee and/or documents from previous meetings, contact MPCA Statewide Mercury Reduction coordinator, Hassan Bouchareb, 651-757-2653.
2024
2023
There was no group meeting in 2022.