For Immediate Release, December 8, 2020


Robert Ukeiley, Center for Biological Diversity, (720) 496-8568,
Anna McDevitt, Sierra Club, (952) 454-6867,

Legal Appeal Filed to Block Massive Expansion of Colorado’s Colowyo Coal Mine

DENVER— Conservation groups filed an appeal today of a district court ruling allowing an approximately 2,000-acre expansion of the Colowyo coal mine in northwestern Colorado.

The lawsuit challenges the state of Colorado’s omission of the majority of particulate emissions from the mine in its air permit calculations, allowing the mine expansion to qualify for a weaker, less protective minor source air permit.

The mine in northwest Colorado has been a source of dirty coal for more than 100 years. Tri-State Generation and Transmission Association Inc., which indirectly owns the mine, has proposed an expansion on state, federal and private land that would increase harmful air emissions by more than 10,000 tons per year.

“Expansion of this coal mine will directly result in more people breathing dirtier, dangerously unhealthy air,” said Robert Ukeiley, a senior attorney at the Center for Biological Diversity. “The coal industry must be forced to reckon with the true cost of the pollution it spews, and Colorado has left us with no choice but to sue to make sure that happens.”

Coal makes it harder to breathe and contributes to global warming, not just when it is burned, but also when it is extracted. Surface coal mines release a toxic soup of air pollution, including methane, nitrogen dioxide and particulates.

Coal pollution causes a range of health and environmental problems:

  • Surface mines account for more than 15 percent of coal mine methane emissions. Methane is a potent heat-trapping greenhouse gas, 25 times more destructive than carbon dioxide.
  • Nitrogen dioxide emissions make it difficult to breathe, including by causing and aggravating asthma. Nitrogen dioxide also reacts with other chemicals in the air to form both particulate matter and ozone, commonly referred to as smog, both of which are harmful to human health. Nitrogen dioxide also causes acid rain.
  • Particulate matter penetrates deep in the lungs where it can enter the bloodstream, impacting both the lungs and the heart.

“All of the emissions from the expanded surface mine and the coal crusher should be counted to determine the necessary controls,” said Anna McDevitt, a senior campaign representative with the Sierra Club. “To do otherwise is to turn a blind eye to significant air emissions that harm human health and our planet.”

The Clean Air Act requires that new sources of air pollution obtain permits based on the amount of pollution that will be emitted. More emissions mean more analysis and more protective measures, including protection for majestic places like the Flat Tops and Mount Zirkel’s wilderness areas.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.