Mercury and coal

Background
Coal-fired power plants are the largest source of mercury in the United States, accounting for about 41 percent (48 tons in 1999) of industrial releases. According to the Centers for Disease Control and Prevention, eight percent of American women of childbearing age had unsafe levels of mercury in their blood, putting approximately 322,000 newborns at risk of neurological deficits. Mercury exposure also can lead to increase cardiovascular risk in adults. When mercury is deposited on land or in water, microorganisms convert part of it to a highly toxic form called methylmercury. When fish and animals eat these microorganisms, the toxins accumulate and can interfere with reproduction, growth, and behavior, and can even cause death.

Regulation and Litigation
The regulatory framework for mercury from coal plants derives from the 1990 Clean Air Act Amendments. Its basic requirement was that coal plants utilize Maximum Achievable Control Technology (MACT), defined as the emissions level of the best performing 12 percent of coal plants. Studies and regulations needed to implement that requirement were slow in coming, and the process was sidetracked entirely when the Bush Administration began pushing a new approach known as the Clear Skies Initiative.

Even though the legislation to enact Clear Skies was not approved by Congress, the U.S. Environmental Protection Agency (EPA) nevertheless attempted to bring via regulatory amendments. In 2005 EPA issued rules exempting coal plants from MACT requirements and instead setting up a “cap and trade” system, allowing plants with stronger controls to sell pollution credits to plants with weaker controls.

Environmentalists objected that the EPA's “cap and trade” system was a backdoor attempt to evade the plain language of the Clean Air Act. Furthermore, because "cap and trade" systems are designed to optimally allocate emissions of a pollutant within an overall national ceiling, they argued that such a system was not suitable for protecting the public from a highly toxic pollutant such as mercury whose uneven deposition patterns tended to create dangerous "hot spots." In February, 2008, the U.S. Court of Appeals for the D.C. Circuit agreed with the Natural Resources Defense Council (NRDC) and other litigants in New Jersey v. U.S. EPA, overturning the cap and trade system for mercury as well as other hazardous air pollutants (HAP) including arsenic, lead, and chromium.

A basic feature of the Clean Air Act is that it allows states to enact their own rules that exceed federal standards. While the EPA delayed regulating mercury, a number of states enacted stiffer regulatory requirements of their own. Compared to the permits for new coal-fired power plants between 2001 and 2005 issued by several states, federal limitations would have allowed from 4 to 20 times more mercury from new coal-fired power plants.

Coal Plants Affected by New Jersey v. U.S. EPA Ruling
According to NRDC, the February, 2008, U.S. Court of Appeals ruling "will increase the pollution control obligations for new coal-fired power plants, raise the already considerable expense of these projects, and add to the weight of arguments that the public deploys to oppose conventional coal-fired plants."

According to NRDC, prospects for the following plants "have been shaken" by the decision:

Georgia
 * Longleaf

Illinois
 * Prairie State Energy Campus
 * Taylorville Energy Center
 * Franklin County Power Plant

Iowa
 * Dairyland Chickasaw/Mitchell Plant
 * LS Power Elk Run Energy Station

Kentucky
 * Cash Creek Generation
 * Spurlock Power Station Unit 3
 * Spurlock Power Station Unit 4

Louisiana
 * Little Gypsy Repowering
 * Big Cajun II Unit 4

Michigan
 * Wolverine Clean Energy Venture
 * Karn/Weadock Generating Complex Expansion
 * Midland Power Plant

Nevada
 * White Pine Energy Station
 * Ely Energy Center, Phase I
 * Toquop

New Mexico
 * Desert Rock

North Carolina
 * Cliffside Plant

Ohio
 * American Municipal Power Generating Station
 * Great Bend IGCC
 * Lima Energy

Pennsylvania
 * River Hill Power Project
 * Beech Hollow Energy Project

Texas
 * Limestone 3
 * Twin Oaks Power Unit 3
 * Sandy Creek Plant

Wyoming
 * Buffalo Energy Project
 * Two Elk Energy Park Unit 1
 * Two Elk Energy Park Unit 2
 * Dry Fork Station
 * Wygen Unit 3

EPA to establish air pollution regulations by 2011
In October 2009, EPA announced it will set standards to require oil- and coal-fired power plants to reduce air pollution. The move settles a lawsuit filed by environmental groups to push EPA to issue limits on mercury emission. Although the Clean Air Act required EPA to issue its rules by 2002, the Bush administration had deemed such regulations unnecessary. Now the EPA has agreed to set pollution standards by March 2011 on mercury and other harmful emissions from power plants. Many power plants will be required to install expensive scrubber equipment to capture heavy metals and particulates. Currently only about a third of power plants use scrubbers. Environmentalists estimate that the new rules could save 35,000 lives per year by 2025. Jim Pew, an attorney at Earthjustice, hailed the agreement as "the Holy Grail of pollution control."

Mercury and fly ash
Coal fly ash is a fine gray powder residue produced by coal-fired power plants and used to make cement. Modern pollution controls in coal plants capture the fly ash before it becomes airborne. As a result, heavy metals such as mercury are concentrated in what the EPA considers "recycled air pollution control residue." In 2006, coal plants in the United States produced almost 72 million tons of fly ash, up 50 percent since 1993.

The use of fly ash in cement kilns in the U.S. has grown from about 1 million tons in 2001 to more than 4 million tons in 2006. Mercury and other metals in fly ash are transformed into vapor and released out of the kiln's smokestack. A 2007 EPA study found that mercury content in ash had increased by up to 850 percent as power plants met stricter federal rules for mercury emissions. The EPA estimates that cement plants produce about 23,000 pounds of mercury per year. In New York's Hudson Valley, the Lafarge cement plant releases between 380 and 400 pounds of toxic mercury per year, equivalent to the four largest coal plants in the state.

The EPA reclassified fly ash from waste to a reusable material in the 1980s. The agency adopted rules favoring cement produced with fly ash in 1983. In 1988, it reported that fly ash was not a hazardous material. The agency exempted ash from regulations for hazardous waste beginning in 1993. With new findings of increased toxic mercury levels, states including New York, Virginia, and Maryland are considering stricter rules to regulate mercury emissions from cement plants.

Tracking the origin of mercury deposits
In October 2008, researchers at the University of Michigan announced they had developed a tool that uses natural "fingerprints" in coal to trace the source of mercury emissions in the environment. The new method is expected to distinguish mercury pollution caused by coal plants from that caused by other industrial activities, as well as to differentiate between different coal deposits. The researchers hope to be able to detect mercury coming from specific coal plants in the United States, and track the movement and deposition of mercury produced by coal plants overseas. The group is currently studying which mercury sources in the San Francisco Bay area are most responsible for the contamination of fish and wildlife.

Mercury in eagles
In November 2008, a study found that eagles in the Catskills region of New York contain more toxic mercury than those in other areas of the state. A quarter of eaglets had elevated blood mercury levels from eating contaminated fish, increasing the likelihood of reproductive or developmental problems in the birds. A quarter of adult birds had elevated levels of mercury in their feathers. The study, conducted by the BioDiversity Research Institute and the New York Department of Environmental Conservation, found that coal-fired power plants in the upper Ohio River basin were the most likely source of the mercury.

Minnesota Pollution Control Agency finds mercury increase in fish from state lakes
In February 2009, the MPCA released a study showing that methylmercury levels in large Minnesota fish including northern pike and walleye had increased unexpectedly. Mercury levels had declined by 37 percent between 1982 and the mid-1990s, but have since increased by 15 percent. The analysis, which was based on tissue samples from fish collected from over 800 state lakes, concerns scientists because the mercury is toxic to humans and wildlife. The agency said that a local source of mercury is not likely to be responsible. Instead, mercury pollution from coal-fired power plants outside the state and factors related to global climate change are probably to blame.

Extensive government study finds mercury contamination in every fish tested
In August 2009, the U.S. Geological Survey released a study of mercury contamination in fish in 291 streams around the country. The study, which is the most comprehensive to date, was conducted from 1998 to 2005 and tested over 1,000 fish. Every fish tested, including those from isolated rural waterways, contained had at least trace amounts of toxic mercury. About 25 percent of fish had levels exceeding what the EPA considers safe for human consumption. According to the researchers, the majority of mercury contamination in the streams tested comes from coal plant emissions. In response to the study, Interior Secretary Ken Salazar commented, "This science sends a clear message that our country must continue to confront pollution, restore our nation's waterways, and protect the public from potential health dangers."

Related SourceWatch resources

 * Mercury pollution