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.
- Minnesota was the first state to prohibit using mercury in dry-cell batteries.
- The mercury from thermostats, thermometers, gauges, medical and scientific equipment, electrical devices, motor vehicles, and household appliances must be removed for reuse or recycling before these products can be disposed of or scrapped.
- Fluorescent lamps must be disposed of at special facilities licensed to recycle mercury.
- Certain toxic substances, including mercury, are prohibited in inks, dyes, pigments, paints, or fungicides as well as in any packaging products.
- MPCA permits limit the amount of mercury incinerators may release.
The federal government has banned using mercury as an agricultural fungicide and in latex paints. The U.S. Environmental Protection Agency has adopted national standards for controlling mercury emissions from coal-fired power plants. Minnesota has joined other states in urging the federal government to work through the United Nations to negotiate a binding treaty to reduce mercury pollution worldwide.
Almost all the mercury in Minnesota’s lakes and rivers is delivered by the atmosphere. Mercury can be carried great distances on wind currents before it is brought down to earth in rain and snow. About 90% of the mercury deposited on Minnesota comes from other states and countries. Similarly, the vast majority of Minnesota’s mercury emissions are carried by wind to other states and countries. It's impossible for Minnesota to solve this problem alone; the United States and other countries must greatly reduce mercury releases from all sources.
Statewide mercury plan
The MPCA prepared a Statewide Mercury Total Maximum Daily Load study (TMDL) that evaluated the sources of mercury and quantified the reductions needed to meet water-quality standards. With substantial stakeholder input, the MPCA prepared a plan to further reduce mercury releases in Minnesota. It includes strategies to keep mercury in water discharges below 24 pounds per year and mercury air emissions below 789 pounds per year.
Minnesota’s Statewide Mercury TMDL was approved by the MPCA Citizens’ Board in December 2006 and by the U.S. Environmental Protection Agency in March 2007. The implementation plan described above details specific strategies that will be employed to achieve the goals of the TMDL.
Minnesota’s mercury reduction rules
To accomplish the reductions specified in the TMDL, the MPCA proposed and later adopted rules regarding mercury reduction plans in Minn. R. 7007.0502. These rules established mercury emissions reductions for certain sources of mercury air emissions to bring both public and privately owned facilities into line with the Statewide Mercury TMDL reduction goals. Described below are the three main parts of the rule amendments the MPCA adopted to accomplish these reductions.
- Mercury reduction plans. Affected facilities must prepare mercury reduction plans for approval and inclusion in a permit or other enforceable document. The rules identify what the reduction plan must include, and establish a schedule for plan submittal for each source category to identify how they will reduce mercury emissions.
- Performance standards. Certain facilities are required to meet performance standards for mercury control. In general, these facilities are already required to meet federal performance standard requirements. This portion of the rules did not impose any new emission reductions or costs beyond what was already required by state statutes or federal standards.
- Emission inventory for mercury. The rule requires facilities to submit a mercury emission inventory to the MPCA. This impacted 35 or fewer facilities. The MPCA currently compiles a voluntary mercury inventory every three years. The rule requires annual emission reporting from the largest sources; small sources with actual emissions less than three pounds per year will continue with the three year inventory.
For additional information about the rulemaking process, visit the Minnesota Revisor’s webpage for the rulemaking and see the additional documents identified below.
- Documents related to the proposed mercury emission inventory and reduction requirements
- Proposed amendments to Minn. R. ch. 7005, 7007, 7011, and 7019
- Statement of Need and Reasonableness (SONAR)
- Estimated Costs Related to the Implementation of the Mercury Reduction Rule, MPCA, July 2013
- Taconite Plant Mercury Rule Compliance Cost Estimate
- List of SONAR attachments (contains webpage links to attachments)
- Fact sheet – Draft Rule on Mercury Air Emissions Reporting and Reduction
- Revised MPCA Response to Comments
- Report of the Administrative Law Judge
- Order Adopting Rules
- Amended Rules
Guidelines for new and modified mercury air emission sources
The Mercury TMDL Implementation Plan included guidelines for increased mercury emissions that result from new sources and modifications to existing sources. The original guidelines were revised in 2012 with stakeholder input. The Guidelines for New and Modified Mercury Emissions Sources are applied to ensure that increases to mercury emissions will not jeopardize the state-wide reduction goal needed to meet water quality standards.
- Guidelines for New and Modified Mercury Air Emission Sources, December 6, 2012
Mercury reduction planning
The requirement to prepare and submit a mercury reduction plan is a result of rules to reduce mercury emissions, Minn. R. 7007.0502, adopted to help make fish safe to eat for all of us. 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 Reduction Plan submittal (aq-ei2-04)
- Mercury Reduction Plan submittal: Ferrous mining/processing (aq-ei2-04a)
Minnesota facilities had the option to avoid submitting a mercury reduction plan if they had an enforceable emissions limit or schedule of mercury reductions that achieved equivalent reductions or reduced emissions below the threshold requiring plan submittal.
Minnesota facilities were also provided the ability to submit an alternative plan to reduce mercury emissions if it was determined that the required mercury reductions are not technically achievable.
A number of Minnesota facilities that emit mercury performed additional testing, modified operations, and/or amended their air quality permit such that mercury emissions were below thresholds and avoided the need to submit a plan.
Reduction plans required by December 30, 2018
Owners or operators of ferrous mining or processing facilities were required to submit a mercury emissions reduction plan by December 30, 2018.
- Ferrous mining or processing facilities are required to reduce mercury emissions by 72% from 2008/2010 emission levels, whichever is greater as determined by the MPCA, by January 1, 2025.
The mercury emissions reduction plan rule allows the facilities to accomplish these reductions at each furnace, across all furnaces at one facility, or across furnaces at multiple facilities (essentially allowing for over-control of one furnace and under-control of others as long as the 72% reduction was met overall).
The mercury emissions reduction plans submitted by the ferrous mining or processing facilities are identified below. MPCA staff will be conducting a thorough review of each plan over the next several months. To date, only a cursory review has been conducted. Based on MPCA staff review of each plan, further discussion may be necessary with individual ferrous mining or processing facilities (or industry as a whole) to discuss the submitted plans and/or revised plans submitted to the MPCA for review and approval.
Two ferrous mining/processing facilities submitted plans with proposed reductions meeting the required 72% reduction specified in the rule:
- Mesabi Metallics Co LLC (formerly known as Essar Steel MN) proposed to use activated carbon injection to reach an expected 74.4% reduction.
- Northshore Mining Company - Silver Bay proposed to utilize work practices and establish a source-wide emissions cap to reach an expected 72.1% reduction.
Two ferrous mining/processing facilities submitted alternative plans with proposed reductions less than the required 72% reduction specified in the rule:
- Mesabi Nugget Delaware LLC proposed to use raw material substitution to manage the amount of mercury emitted to reach an expected 50% reduction.
- ArcelorMittal Minorca Mine Inc. proposed to utilize the existing wet scrubber controls with solids removal to prevent the reintroduction of mercury into the induration process to reach an expected 22% reduction.
Four ferrous mining/processing facilities submitted alternative plans with no proposed reductions. Hibbing Taconite Company, United Taconite LLC - Fairlane Plant, and U.S. Steel Corporation - Keetac and Minntac proposed no further reductions were technically achievable and proposed to conduct further literature and engineering review beginning in mid-2020.
- Mercury Reduction Plan: Hibbing Taconite Company (aq-ei2-12a)
- Mercury Reduction Plan: United Taconite, LLC - Fairlane Plant (aq-ei2-13a)
- Mercury Reduction Plan: US Steel Corporation - Keetac (aq-ei2-14a)
- Mercury Reduction Plan: US Steel Corporation - Minntac (aq-ei2-15a)
Reduction plans required by June 30, 2015
Owners or operators of an existing mercury source (those with an air emissions permit issued as of September 29, 2014) were required to submit a mercury reduction plan by June 30, 2015.
- Boiler owners/operators with individual emissions greater than 5 pounds were required to comply with the applicable federal regulations and ensure that a reduction of at least 70% was achieved by January 1, 2018.
- Iron and steel melters were required to reduce mercury emissions to less than 35 milligrams per ton of iron/steel produced by June 30, 2018.
- Mercury emission sources with processes that individually emit three or more pounds of mercury per year were required to reduce emission emissions by at least 70% by January 1, 2025.
American Crystal Sugar - East Grand Forks was the only industrial boiler facility required to submit a reduction plan for their boilers. The submitted reduction plan proposed to limit mercury emissions from their two boilers to less 10 pounds per year total to meet the rule exemption in Minn. R. 7007.0502, subp. 6(C)(1)(a) that states further reductions, above and beyond federal requirements, are not required for boilers with mercury emissions that are less than five pounds per year. American Crystal Sugar - East Grand Forks’ mercury reduction plan is available below.
Gerdau Ameristeel, an iron and steel melter, proposed to install a new activated carbon injection control system to meet the required mercury reductions. This system was proposed to be used alongside the existing fabric filter controls to meet the target 35 milligrams of mercury emitted per ton of iron/steel produced. Gerdau Ameristeel’s mercury reduction plan is available below.
- Mercury Reduction Plan: Gerdau Ameristeel Submittal
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 expects to meet annually from 2009 through 2025. The MPCA expects to annually convene this group (in the fall), allowing time for monitoring information, emission estimates and reporting from the previous year to be gathered and analyzed.
Below are the presentations and emissions inventory documents from the three most recent meetings of the Statewide Mercury TMDL Implementation Plan Oversight Committee.
- Agenda - Statewide Mercury TMDL Implementation Plan Oversight Committee Meeting (wq-iw4-02j1)
- 2021 MPCA mercury updates (wq-iw4-02j2)
- Taconite iron ore processing NESHAP (wq-iw4-02j3)
- MATS compliance retrospective (wq-iw4-02j4)
- 2020 mercury TMDL emissions inventory update (wq-iw4-02j5)
- Minnesota mercury emissions inventory methodology (wq-iw4-02j6)
- Mercury isotopes - A new tool for understanding mercury sources and cycling (wq-iw4-02j7)
- 2020 statewide mercury TMDL emissions inventory (wq-iw4-02j8)
- Agenda: Statewide mercury TMDL implementation plan oversight committee meeting (wq-iw4-02i1)
- Mercury TMDL emissions inventory update (wq-iw4-02i2)
- Mercury TMDL for the St Louis River (wq-iw4-02i3)
- Understanding and reducing mercury impacts to Lake Superior (wq-iw4-02i4)
- MPCA review - Taconite mercury reduction plans (wq-iw4-02i5)
- Federal taconite ore processing RTR overview (wq-iw4-02i6)
- Path forward discussion questions (2020) (wq-iw4-02i7)
- 2018-2019 Statewide mercury TMDL emissions inventory (wq-iw4-02i8)
- Agenda - Statewide mercury TMDL implementation plan oversight committee meeting (wq-iw4-02h1)
- 2019 Welcome presentation (wq-iw4-02h2)
- 2019 State of the knowledge on mercury (wq-iw4-02h3)
- Minnesota Department of Health updates on mercury surveillance and outreach (wq-iw4-02h4)
- Taconite industry mercury research, testing, and technology evaluation (wq-iw4-02h5)
- Mercury and wastewater treatment (wq-iw4-02h6)
- 2017 Statewide mercury TMDL emissions inventory (wq-iw4-02h7)
For more information about mercury pollution in Minnesota and how the MPCA is addressing the problem, contact MPCA Statewide Mercury Reduction coordinator, Hassan Bouchareb, 651-757-2653.
Other states with mercury TMDL studies
- North Carolina
- Northeast region: Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island, Vermont
- San Francisco Bay Mercury TMDL
- South Dakota