Coal Ash – What You Need to Know
The 1.05 billion tons of coal burned each year in the United States contain 109 tons of mercury, 7884 tons of arsenic, 1167 tons of beryllium, 750 tons of cadmium, 8810 tons of chromium, 9339 tons of nickel, and 2587 tons of selenium. On top of emitting 1.9 billion tons of carbon dioxide each year, coal-fired power plants in the United States also create 120 million tons of toxic waste. That means each of the nation’s 500 coal-fired power plants produces an average 240,000 tons of toxic waste each year. A power plant that operates for 40 years will leave behind 9.6 million tons of toxic waste.
This coal combustion waste (CCW) constitutes the nation’s second largest waste stream after municipal solid waste.
When coal is burned, toxins in the coal are released into the smokestack. With modern air pollution controls, airborne toxins are captured through filtration systems before they can become airborne, and contained in a fine ash called coal ash, fly ash, or coal combustion waste. As a result, heavy metals such as mercury are concentrated in what the EPA considers “recycled air pollution control residue.”
Coal ash contains large quantities of toxic metals, including 44 tons of mercury, 4601 tons of arsenic, 970 tons of beryllium, 496 tons of cadmium, 6275 tons of chromium, 6533 tons of nickel, and 1305 tons of selenium. In 2006, coal plants in the United States produced almost 72 million tons of fly ash, up 50 percent since 1993.
Sulfur dioxide scrubbers also create coal waste. The flue-gas desulfurization (FGD) process creates a wet solid residue containing calcium sulfite (CaSO3) and calcium sulfate (CaSO4). Often dry material such as fly ash is added to stabilize the sludge for transport and landfill storage.
Most often coal waste is disposed of in landfills or “surface impoundments,” which are lined with compacted clay soil, a plastic sheet, or both. As rain filters through the toxic ash pits year after year, the toxic metals are leached out and pushed downward by gravity towards the lining and the soil below. An EPA study found that all liners eventually degrade, crack or tear, meaning that all landfills eventually leak and release their toxins into the local environment.In a best case scenario, the EPA study determined that a 10-acre landfill would leak 0.2 to 10 gallons per day, or between 730 and 36,500 gallons over a ten-year period, an amount guaranteed to infiltrate the drinking water supply.
On February 24, 2010 Environmental Integrity Project and Earthjustice released a report that indicated that at least 31 “new damage cases” were not listed by the EPA in its end of 2010 tally that included 70 coal-ash pollution sites. Coal ash-waste ponds and coal waste landfills are leaching toxins into streams and drinking water, the report noted. As reported in the Christian Science Monitor:
- The groups identified the sites by assembling contamination data from state files using “similar criteria” to those sites the EPA had already identified, the report says. Arsenic, selenium, and boron were among the dangerous chemicals found to have “migrated off” nearly half of the 31 sites where coal-fired power plants store their coal ash…
- The 31 identified sites are spread across 14 states, including Delaware (1), Florida (3), Illinois (1), Indiana (2), Maryland (1), Michigan (1), Montana (1), Nevada (1), New Mexico (1), North Carolina (6), Pennsylvania (6), South Carolina (3), Tennessee (2), and West Virginia (2).
The report concluded that the EPA must regulate coal ash waste in order to protect the public and the environment from the negative effects of coal waste.