Coal seam fires add to power plant emissions, mercury levels

Researchers at the South Dakota School of Mines already know most of the mercury in the state's lakes has precipitated from emissions released from coal fired power plants in North Dakota, Montana and Wyoming. 

And, if South Dakota had a Democratic attorney general she'd sue those states for the toxic legacy created by Colstrip, Basin Electric and Black Hills Energy. One of the most polluted reaches of the Belle Fourche River goes right through current Republican Attorney General Marty Jackley's boyhood ranch. 

In 2020 Minnesota Attorney General Keith Ellison sued ExxonMobil, Koch Industries and the American Petroleum Institute for lying to residents of that state about emissions levels. NorthWestern Energy owns 23.4% of the Big Stone Power Plant in northeastern South Dakota — a monster that consumes 3,500 tons of filthy sub-bituminous coal every hour then spews heavy metal oxides and carbon dioxide over Minnesota.

But, the volume of mercury and other heavy metals released by wildfires in Canada and United States is well-documented, too.

In 2012 the fast-moving Ash Creek Fire burned bridges on US212 near Ashland and Lame Deer, Montana while another blaze nearby on the Northern Cheyenne Reservation, the Coal Seam Fire spread to some 700 acres. In 2017 wildland fires on private ranch land in southeastern Montana dwarfed those on public ground in the western part of the state. In 2021 a smoldering coal seam started the Richard Spring Fire on the Ashland District of the Custer Gallatin National Forest that burned primarily in non-native cheatgrass beneath a ponderosa pine overstory. 

Within the Fort Union Formation under eastern Montana, North Dakota, South Dakota and Wyoming are maybe thousands of coal seams. The Box Car coal seam has been burning since 1913 and in Custer County, Montana there are some 320 that caused at least 51 wildfires in 2021 alone.

A burning coal seam might have ignited the Marshall Fire in Boulder County, Colorado that evaporated over a thousand homes, caused over two billion dollars in damage and released tons of deadly emissions.

The CO2 from these fires adds about 1% to the world’s total greenhouse gas emissions from fossil fuels. Added to all the other coal-seam fires in the world, this is a largely unreported global catastrophe. [Uncontrolled coal-seam fires are catastrophic polluters]

Because of mercury emissions from burning Wyoming coal Black Hills Corp. decommissioned its Rapid City plant in 2012 then converted it to natural gas and PPL Montana shuttered the JE Corette Plant in Billings in 2015. Black Hills Energy still operates five coal-burning brutes in Wyoming’s Powder River basin just a few miles upwind of Spearditch, South Dakota. 

In the spring, summer and sometimes in the early fall months the Black Hills Convergence Zone weather phenomenon creates supercells and concentrates particulates from Wyoming power plants in the northern Hills and northeast plains making area waterways more toxic like has happened in the Belle Fourche Reservoir, Newell and Bear Butte Lakes.

Learn more about fish consumption advisories for metals, pesticides and polychlorinated biphenyls in South Dakota linked here.

The @EPA is pushing to tighten standards for mercury emissions from coal-burning power plants—it'll improve public health, especially for those living near the power plants, often low-income communities. https://t.co/LA25zpZulk

— NRDC 🌎🏡 (@NRDC) May 13, 2023