Mercury and Air Toxics Standards

From Global Energy Monitor

The Mercury and Air Toxics Standards (MATS) (also known as the Utility MACT) are EPA standards for all hazardous air pollutants (HAPs) emitted by coal- and oil-fired electric generating units (EGUs) with a capacity of 25 megawatts or greater. The regulations were issued under a Consent Decree of the D.C. Court of Appeals requiring EPA to issue a proposal by March 16, 2011, and a final rule in December 16, 2011. According to the EPA, "Until now there have been no federal standards that require power plants to limit their emissions of toxic air pollutants like mercury, arsenic, and heavy metals - despite the availability of proven control technologies, and the more than 20 years since the 1990 Clean Air Act Amendments passed."[1]

The EPA estimates that between 4,000 and 11,000 premature deaths can be prevented each year by the Standards, with total economic benefits measured at between $37 billion and $90 billion annually. The pollution control upgrades are expected to create up to 45,000 temporary construction jobs and 8,000 permanent jobs.[2]

Members of the Senate, led by James Inhofe of Oklahoma, brought a Congressional Review Act (CRA) in June 2012 to try and overturn MATS and block the EPA from passing similar standards in the future. The measure failed, with 46 senators voting for it and 53 against it. The CRA was passed as part of Newt Gingrich's Contract With America after the 1996 elections, to “impose new restraints on the so-called ‘independent’ Agencies.”[3]


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.[4] 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.[5]

The 2011 Environmental Defense Fund report, "Mercury Alert: Cleaning up Coal Plants for Healthier Lives" found that 25 plants alone are responsible for nearly a third of all mercury emissions in the power sector, while providing only eight percent of U.S. electricity. Twenty of them are located within 50-100 miles of some of the largest metropolitan areas in the country, including Chicago, Dallas, Houston, Atlanta, Minneapolis, Detroit, Pittsburgh, Cleveland, St. Louis and Austin. Texas led the nation in mercury air pollution from coal-fired power in 2009.[6]

Regulation and Litigation under the Bush Administration

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."

Columnist Paul Krugman charged: "On mercury, the administration didn't just take industry views into account, it literally let the polluters write the regulations: much of the language of the administration's proposal came directly from lobbyists' memos. ... In other words, the administration proposal would perpetuate mercury pollution where it does the most harm. That probably means thousands of children born with preventable neurological problems." [7]

According to the New York Times, the Bush administration worked closely with the coal industry to craft its regulations on mercury:[8]

Coal and utility groups lobbied intensively to help shape the regulations, which will cost billions of dollars. Paragraphs in the proposed rules are inserted nearly verbatim from memorandums from the firm of Latham & Watkins, where two top political officials in the E.P.A.'s office overseeing air regulations, Bill Wehrum and Jeffrey Holmstead, once worked.
While working with Environmental Protection Agency officials to write regulations for coal-fired power plants over several recent months, White House staff members played down the toxic effects of mercury, hundreds of pages of documents and e-mail messages show.
The staff members deleted or modified information on mercury that employees of the environmental agency say was drawn largely from a 2000 report by the National Academy of Sciences that Congress had commissioned to settle the scientific debate about the risks of mercury.
In interviews, 6 of 10 members of the academy's panel on mercury said the changes did not introduce inaccuracies. They said that many of the revisions sharpened the scientific points being made and that justification could be made for or against other changes. Most changes were made by the White House's Office of Management and Budget, which employs economists and scientists to review regulations.
The proposed regulations are available on the E.P.A. Web site ( The proposed rules would limit mercury emissions by an estimated 70 percent over decades and would also allow power plants to buy and sell among themselves the rights to create mercury pollution.
While it is standard for the White House to review federal agency testimony and reports, E.P.A. staff members say the Bush administration also minimized the amount of mercury that comes from power plants. Over agency staff objections, the White House on several occasions in the past year added the statement that coal burning produces 'roughly one percent of mercury in the global pool.
According to the E.P.A. staff, the 1 percent figure was added to an agency report on children's health; Senate testimony by Christine Todd Whitman, who was the E.P.A. administrator; and Senate testimony of Mr. Holmstead, who is the assistant agency administrator for air.
While that figure is cited in the E.P.A.'s 1997 report to Congress, agency staff members and independent scientists say it is misleading because much of the mercury that ends up in the nation's water and soil comes from nearby sources.

Regulation Under the Obama Administration

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."[9]

In a motion filed on December 7, 2010, the EPA asked for an extension in the current court-ordered schedule for issuing rules that would reduce harmful air emissions from large and small boilers and solid waste incinerators, which would cut emissions of pollutants, including mercury and soot. EPA is under a current court order to issue final rules on January 16, 2011 and is seeking in its motion to the court to extend the schedule to finalize the rules by April 2012. The agency said the additional time is needed "to re-propose the rules based on a full assessment of information received since the rules were proposed."[10]

March 2011: New EPA Standards for Mercury and Air Toxics Proposed

On March 16, 2011, the U.S. Environmental Protection Agency (EPA) announced its proposed emissions standards to limit mercury, acid gases and other toxic pollution from power plants, to prevent an estimated 91 percent of the mercury in coal from being released to the air. The EPA estimates that there are approximately 1,350 units affected by the action, including 1,200 existing coal-fired units.[11]

There are currently no existing national limits on the amount of mercury and other toxic air pollution released from power plant smokestacks. The 1990 Clean Air Act Amendments mandated EPA control toxic air pollutants, and the EPA took action to reduce mercury emissions from the highest-emitting sources, except power plants, as the Clean Air Mercury Rule passed under President George W. Bush was vacated by a court.[11]

The proposed toxics rule would reduce emissions of heavy metals, including mercury (Hg), arsenic, chromium, and nickel, and acid gases, including hydrogen chloride (HCl) and hydrogen fluoride (HF). EPA is also proposing to revise the New Source Review performance standards (NSPS) for fossil-fuel-fired plants. This NSPS would revise the standards new coal- and oil-fired power plants must meet for particulate matter (PM), sulfur dioxide (SO2), and nitrogen oxides (NOx). The proposed standards should reduce mercury emissions from power plants burning coal and oil by 91 percent, acid gas pollution by 91 percent, direct particulate matter emissions by 30 percent, and sulfur dioxide (SO2) emissions by 53 percent, down to 2.1 million tons of annual SO2 emissions.[11]

The EPA's proposed standards are projected to save as many as 17,000 lives every year by 2015; prevent up to 120,000 cases of childhood asthma symptoms and 11,000 fewer cases of acute bronchitis among children every year; avoid more than 12,000 emergency room and hospital visits annually; and prevent 850,000 lost work days every year. The monetized benefits from the improved health standards are estimated to be $59 billion to $140 billion annually, compared to annual compliance costs of approximately $10.9 billion. The EPA also projects that the proposed standards will create up to 31,000 short-term construction jobs and 9,000 long-term utility jobs.[12]

Requirements of the new standards include:[11]

  • For all existing and new coal- and oil-fired electric utility steam generating units (EGUs), the proposed standards would establish numerical emission limits for mercury, PM, and HCl.
  • For all existing and new oil-fired EGUs, the proposed toxics rule would establish numerical emission limits for total metals, HCl, and HF.
  • Actions available to power plants to meet the emission limits include wet and dry scrubbers, dry sorbent injection systems, activated carbon injection systems, and baghouses, all part of Maximum Achievable Control Technology (MACT).
  • The proposed standards would establish work practices, instead of numerical emission limits, to limit emissions of organic air toxics, including dioxin/furan, from existing and new coal- and oil-fired power plants.
  • The proposed revisions to the NSPS would include revised numerical EGU emission limits for PM, SO2, and NOX.

December 2011: New rule announced

In December 2011, the Obama administration announced the new rule to limit emissions of mercury, arsenic and other toxic substances from sources such as power plants. Under the new rule, power plants can emit 1.2 pounds of mercury per million BTUs of energy produced. Industry had sought a limit of 1.4 pounds, but the EPA arrived at its figure based on a formula set out under the Clean Air Act, and analysts said the agency could not deviate from it. Companies would have three years to clean up their emissions of mercury and about 70 other toxic substances, and utilities could appeal for at least one more year as they install the necessary equipment.[13]



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