Mercury is known as god of commerce in Roman mythology as well as protector of thieves in Greek mythology, not to mention conveyer of souls to the underworld. In the real world, mercury is a neurotoxin that enters the blood stream through the lungs and digestive tract. It is also one of the many gifts of coal.
All coal releases some mercury into the air when it is burned. Some coal, like the lignite coal from Texas, produces a great deal of it. The mercury in the particulate matter going up the stacks of coal-fired plants contaminates soil and streams, where it accumulates in the flesh of fish. The technology exists to remove it from the emissions, but no progress has been made during the past decade to cleaning up yet another dirty byproduct of coal energy.
Like many issues surrounding coal, the state and federal officials have dithered rather than protect the public.
Here are a few background points on coal and mercury. As noted by the EPA, "coal-burning power plants are the largest human-caused source of mercury emissions to the air in the United States, accounting for over 40 percent of all domestic human-caused mercury emissions." Thanks largely to coal, nearly half of the nation's streams, lakes, reservoirs, and coastal waters have mercury levels in excess of safe limits. And as a result of high levels of mercury in our waterways, the EPA has also found "mercury concentrations in game fish exceeding EPA’s recommended levels at 49 percent of lakes and reservoirs nationwide."
Exposure to mercury in the air, water, and consumption of tainted fish can have very serious health consequences. The Centers for Disease Control conducted a large scale population study in 2003 and found that 8% of women of child-bearing age had high levels of mercury in their bloodstream, which puts more than 300,000 infants each year at risk for learning and other developmental problems due to the neurotoxic effects of mercury transmitted in utero or in breast milk. Consumption of mercury-tainted fish is hazardous and has led many states to issue warnings to limit consumption of wild-caught fish. The classic example of mercury poisoning via fish consumption is the Minamata disaster in Japan where thousands developed severe neurological disorders or died. The culprit in this case was mercury discharged into the sea from a chemical company. For more information on methylmercury toxicity see this EPA fact sheet.
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The Environmental Integrity Project shines a light on coal-fired mercury pollution
The Environmental Integrity Project (EIP) has lead the fight against toxic contamination from coal combustion waste, raising public awareness of groundwater contamination at 31 coal ash impoundments. A new EIP report documents mercury emissions at coal-fired power plants. This report examined mercury emissions reported to the EPA's Toxic Release Inventory with detailed examination of data for the years 2007 and 2008.
Key findings from the EIP report:
(1) Mercury emissions have remained essentially unchanged over the past decade despite the availability of scrubber technology to eliminate most of the emissions.
(2) Texas is the leading state for mercury emissions from coal-fired plants. It is home to 5 of the top 10 mercury-emitting plants and 7 of the top 50.
(3) Much of the mercury emissions in Texas can be traced to four plants run by Luminant (formerly TXU). These four plants account for 6% of the mercury emissions in the United States. Luminant is bringing two more plants on line this year using similar technology and coal sources as the four high emissions plants.
(4) American Electric Power's Gavin plant in Gallia County, Ohio, more than doubled its mercury emission rate between 2007 and 2008.
The top 10* mercury emissions plants:
- Martin Lake facility in Rusk Country, TX, operated by Luminant
- Big Brown facility in Freestone County, TX, operated by Luminant
- Scherer facility in Monroe County, GA, operated by Southern Company
- Labadie facility in Franklin County, MO, operated by Ameren
- Monticello facility in Titus County, TX, operated by Luminant
- Limestone facility in Limestone County, TX, operated by NRG
- Miller facility in Jefferson County, AL, operated by Southern Company
- Monroe facility in Monroe County, MI, operated by DTE
- Pirkey facility in Harrison County, TX, operated by American Electric Power
- Keystone facility in Armstrong County, PA, operated by American Electric Power
[*For the list of the top 50 mercury emissions plants see pages 6-7 of the EIP report.]
Each of these plants dumped more than 1000 pounds of mercury into the air and contaminated water in the surrounding areas. Microbial action transforms the mercury released by coal-fired plants into methylmercury, a highly toxic soluble form that accumulates in fat tissue. Mercury levels in the air, soil, and water around these and other coal-fired plants far exceed safety standards set by the EPA.
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Additional points
Mercury composition of coal varies so I decided to examine the source of coal for the top 50 mercury-emitting plants. The plants in east Texas burn lignite coal from strip mines near the plants. Several other plants burn lignite from the Dakotas and Mississippi. The rest use coal from the Powder River Basin (eastern Wyoming, eastern Montana, western South Dakota) - map of coal seams here. Lignite and Powder River Basin coal are low in sulfur which can be burned without installing scrubbers to meet sulfur dioxide emission caps. Lignite and Powder River Basin coal also have low chlorine content, which limits the effectiveness of scrubbers unless the coal is subjected to a special process before burning.
The mercury content of the coal ash when burned is also high, providing yet another source of mercury in the waste stream linked to coal energy. Further, secondary uses of mercury-tainted coal ash can be problematic. For example, the use of mercury-tainted coal ash in cement allows additional mercury contamination. Here is a story about mercury contamination in the Albany, NY area that can be traced to cement plant using mercury-tainted ash.
Ward Stone, a wildlife pathologist with the state Department of Environmental Conservation, will discuss his findings Tuesday in Ravena, where he will report elevated mercury levels in wildlife, including a possum and shrews; high mercury levels in trees and soils, including in Mosher Park in the village of Ravena, and high levels of calcium, possibly from rock dust stemming from nearby limestone quarrying at the cement plant along Route 9W close to the Ravena-Coeymans-Selkirk school.
DEC officials are considering a renewal of Lafarge's air pollution permit, and last year proposed a permit that would allow mercury emissions of up to 176 pounds a year -- a level that still would keep the plant as the state's second-largest airborne mercury polluter.
Mercury is a potent neurotoxin that is dangerous to developing fetuses and pregnant women. It can enter the food chain through water.
In 2008, Lafarge announced that it expected to modernize the plant by 2016 by converting its wet-kiln process, which includes mercury-tainted coal fly ash as an ingredient in cement-making, to a less-polluting dry kiln. DEC has promised to stop Lafarge from using fly ash, but that has not happened yet.
Albany Times Union
Note that the mercury emissions from the LaFarge cement plant are only 10% of the high mercury-emitting coal-fired power plants, yet mercury levels are readily detectible in soils and wildlife.
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The EPA emission standards for mercury emissions from power plants
Utilities have been exempted from mercury emission limits under the Clear Air Act since 1990. The Bush administration attempted to create a worthless cap-and-trade scheme that would have removed the exception but allowed utility companies to continue to emit high levels of mercury from some plants as long as most of the plants were within standard. It was essentially a business-as-usual scheme but was struck down by the D.C. Circuit Court in February, 2008. The Bush administration had petitioned the Supreme Court to review the Circuit Court decision. When Obama took office, the Justice Department asked the Supreme Court to dismiss the petition from Bush administration. EPA intends to propose air toxics standards for coal- and oil-fired electric generating units by March 10, 2011 and finalize a rule by November 16, 2011.
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Some final thoughts
When Luminant brings on two additional coal-fired plants on line this year that will also burn lignite coal, these plants will account for nearly 10% of mercury emissions in the United States. That concentration of mercury in eastern Texas will put local residents at risk for neurotoxic complications, especially infants exposed in utero or in breast milk because of high levels of mercury in their mother. Mercury disrupts nervous system development at critical periods. Luminant is going to resist changing the fuel source for these plants because lignite is cheap, particularly when obtained from nearby strip mines owned by the company. The plants were built in proximity to the lignite mines because lignite cannot be shipped long distances (it is prone to spontaneous combustion).
And did you know that a major owner of Luminant is none other than Goldman Sachs? This gives new meaning to the term 'toxic assets.'