Exposed: Coal Combustion

Coal is currently the largest source of global energy. When coal is burned, its carbon, hydrogen, oxygen, sulfur, nitrogen and trace metals combine to form greenhouse gases such as carbon dioxide, methane and nitrogen oxides. Other emissions include sulfur dioxide gas, which can contribute to acid rain and respiratory diseases, particulate matter, which can cause lung and heart disease and mercury gas, a neurotoxin.

Photo courtesy of Appalachian Voices

Clean Air Act regulations have pressured power plants to reduce certain emissions such as sulfur gases, but ultimately, once devices known as scrubbers remove these pollutants from the air, the resulting toxic sludge instead pollutes our water. This scrubber sludge is often mixed with coal ash — another byproduct of burning coal for electricity — and contaminants such as arsenic, lead, mercury and selenium are much more concentrated in coal ash than in coal itself.

Disposal of this toxic waste is highly controversial. According to a 2007 study by the nonprofit Clean Air Task Force, coal ash is the largest source of industrial waste in the United States, yet there a few state rules and — at press time — no federal rules directly regulating its disposal. Due to this, no matter whether the waste is mixed with water and stored in open-air, unlined ponds, injected into abandoned mines, or dried out and shipped to municipal landfills, contamination of air and water can — and does — occur daily.

Though exact numbers remain unknown, a 2010 investigation of 137 of the more than 1,300 coal ash ponds across the nation revealed that “when adequate monitoring systems are established and their results are publicly accessible, contamination is invariably found at virtually every coal ash pond and landfill currently operating.”