EPA proposes mercury limits from iron ore processing

Agency is accepting public comments through June 29 on proposed regulations that supporters say would help protect the environment

The U.S. Environmental Protection Agency is accepting public comments until June 29 on proposed revisions to emission standards for mining operations that process taconite, a low-grade iron ore.

The EPA estimates the standards will reduce mercury emissions by approximately 57 percent — mercury emissions were not included in emission standards adopted 20 years ago — and will further reduce hydrogen chloride and hydrogen fluoride emissions.

Hydrogen chloride and hydrogen fluoride emissions are acid gasses that have been demonstrated to cause adverse health effects, including “chronic and acute disorders of the blood, heart, kidneys, reproductive system, respiratory system and central nervous system,” the EPA reported.

Several tribal nations and the environmental law organization Earthjustice welcomed the mercury emission standards — they sued EPA to set the limits — but say the standards don’t go far enough to protect the environment and human health.

The new standards would apply nationwide, but taconite is currently mined in only three states – Michigan, Minnesota and Wisconsin.

Tribal nations in those states have treaty rights to harvest fish in their usual and accustomed areas, and fish is a critical and historical part of the Indigenous diet. All of the mines in Minnesota and Michigan are located near rivers, streams or lakes. Tribes submitted data showing elevated levels of mercury in the fish they eat.

“The State of Minnesota has issued mercury fish consumption advisories for 1,239 water bodies, including 820 lakes and 419 rivers,” Joy Wiecks, the air coordinator for the Fond du Lac Band of Lake Superior Chippewa, wrote in comments submitted to the EPA.

“Similarly, the State of Wisconsin has safe-eating guidelines for ‘most’ Wisconsin waters, although 146 waters are singled out for stricter guidelines. The State of Michigan also has advisories that cover all state water bodies.”

Taconite is a rock that contains iron. Rock crushers and magnets are used to extract the iron, which is ground into a powder in rotating mills and mixed with water and clay to form pellets that are heated in blast furnaces until they are white hot. The pellets become solid when cool, and are then transported to steel mills by rail car or ship.

The largest source of taconite in the U.S. is the Hull Rust Mahoning Mine in Hibbing, Minnesota. According to the Minnesota Department of Natural Resources, the mine is the world’s largest open-pit iron ore mine and made its first iron ore shipment in 1895. The mine’s owners began crushing and processing taconite ore when the supply of high-grade natural iron ore decreased.

The Hull Rust Mahoning Mine is operated by the Hibbing Taconite Co., which is co-owned by Cleveland-Cliffs and U.S. Steel. The Hibbing Taconite Company produces about 7.8 million tons of standard iron-bearing pellets, and mines about 29 million tons of ore annually, according to the company website.

Six companies own or co-own iron mines in Minnesota: ArcelorMittal, Cleveland-Cliffs, Kobe Steel, Magnetation, Steel Dynamics, and U.S. Steel. The mines are located along a 110-mile, ore-rich swath of northeast Minnesota’s Mesabi Range — in the towns of Babbitt, Chisholm, Forbes, Hibbing, Hoyt Lakes, Keewatin, Mountain Iron, Silver Bay and Virginia.

Cleveland-Cliffs also owns the Empire and Tilden mines near Ishpeming, Michigan, within the historical territory of the Keeweenaw Bay Indian Community.

Cost is less than 1 percent of revenue

The EPA believes electrostatic precipitators effectively capture mercury particles from exhaust gasses produced by blast furnaces in which taconite pellets are made.

EPA estimates the annual cost of operating and maintaining the additional emission controls would be $8 million per facility — “less than 1 percent of annual sales revenue per owner,” EPA reported.

Meanwhile, the revised standards are projected to reduce total hazardous air pollutants by 751 tons per year and reduce mercury emissions by 497 pounds per year, EPA reported.

In a comment letter, the American Iron and Steel Institute and U.S. Steel wrote that the EPA set its standards based on an inflated daily fish consumption rate, and that the operation and maintenance of electrostatic precipitators “would impose staggering costs on the industry, which are not justified in light of the relatively small reduction they would lead to.”

ICT reached out to Cleveland-Cliffs for comment on June 20. The company’s reaction to the proposed emission standards and revisions were not known, but the company states in documents available online that it is committed to reducing greenhouse gas emissions 25 percent by 2030 from 2017 levels. It reported that it is using porous iron briquettes in its blast furnaces to reduce carbon emissions, upgrading its onsite energy recovery for power generation, and using renewable energy.

Concerns beyond emissions

The Great Lakes Indian Fish & Wildlife Commission represents 11 Ojibwe tribes in Michigan, Minnesota and Wisconsin who reserved hunting, fishing and gathering rights in 1836, 1837, 1842, and 1854 treaties with the U.S. government. The commission produced a report on taconite mining in its spring/summer 2012 magazine that told of the region’s prolific production — and laid out the organization’s concerns that go beyond emissions.

“A taconite mine that produces 8 million tons of taconite pellets per year could generate approximately the following amounts of material: 24 million tons of ore mined per year (3 tons of ore per 1 ton of taconite pellets), 24 million tons of waste rock per year, 16 million tons of tailings per year, and 8 million tons of taconite pellets per year,” the commission reported. “An iron mine of this scale could generate approximately 560 million tons of tailings and 840 million tons of waste rock over a mine life of 35 years.”

Tailings are the rocks that are left over after the resource is extracted. Tailings can contain heavy metals, sulfides and radioactive content that can be carried away by stormwater, contaminating aquifers, streams and lakes. Tailings are often stored in man-made ponds where contaminated stormwater can be contained.

The commission reported that mines in Michigan and Minnesota “show that elevated levels of selenium (e.g. Tilden Mine, Mich.), sulfate (e.g. Minntac Mine, Minn.), manganese (e.g. Cliff Erie Mine, Minn.), and asbestos-like fibers (e.g. Reserve Mining, Minn.) can be a problem in water discharges.”

Fond du Lac Band Chairman Kevin Dupuis said in a statement issued by Earthjustice, “We welcome limits on taconite plants’ emissions of mercury, which are badly needed and long overdue. EPA needs to go further, however, and set stronger limits for mercury as well as limits for dioxins and other persistent pollutants that are poisoning our fish and waterways.”