Controlling Power Plant Emissions: Decision Process and Chronology

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Controlling Power Plant Emissions

Decision Process
Chronology of Actions to Date

Decision Process

EPA issued the final Clean Air Mercury rule on March 15, 2005 after more than a decade of discussion. In determining the best approach for regulating mercury emissions from coal-fired power plants for the first time in our nation’s history, the Agency remained committed to an open, inclusive and rigorous decision process. This comprehensive mercury web site was launched in 2004 to provide the public with a broad range of information on mercury and to present information on the Agency’s deliberations during the decision phase.

In choosing a regulatory approach, EPA followed five Guiding Principles that provided a context for additional inquiry and narrowed the focus of Agency deliberations. EPA studied mercury health impacts, control technologies, economic consequences of regulation and domestic and international emission sources. We met with a wide range of experts and stakeholders to understand the many complex perspectives on these issues.

The chronology below outlines more than a decade of work leading to the March 15, 2005 rule.

Top of page

Historical Summary of Mercury Decision-Making

The Clean Air Act Amendments of 1990 promulgated.
Deadline passed:
EPA missed November 15, 1993 deadline for submitting to Congress study on risks of hazardous air pollutants (HAPs) from power plants.
Litigation and settlement:
- Natural Resources Defense Council (NRDC) sued EPA in 1992 for not including power plants on initial section 112(c) list of sources to be regulated under 112.
- Sierra Club sued EPA in 1994 for missing deadline to complete report to Congress.
- EPA settles both suits in 1994 and, in 1997, submitted Mercury Study Report to Congress.
Regulatory determination:
On December 20, 2000 EPA published a determination to proceed with the regulation of mercury emissions from power plants and committed to first proposing specifics by December 15, 2003.
Proposed rule:
On December 15, 2003 the Administrator signed a proposal to reduce mercury emissions from coal-fired power plants.
Extended comment period and decision deadline:
At the request of NRDC, EPA extended the comment period two months and extended the deadline for a final decision three months.
Final rule issued
On March 15, 2005, EPA issued the Clean Air Mercury Rule to permanently cap and reduce mercury emissions from coal-fired power plants for the first time ever. This rule makes the United States the first country in the world to regulate mercury emissions from utilities.
Clean Air Mercury Rule (CAMR) Reconsideration Granted
On October 21, 2005, EPA granted reconsideration of its regulatory finding on utility emissions and on the CAMR.
Final Decision on CAMR Reconsideration
On May 31, 2006, EPA issued a final rule to reconsider its regulatory finding on utility emissions and on the CAMR. The Agency reaffirmed its regulatory decision and made technical changes and clarifications to the CAMR.

Chronology of Actions to Date

You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more.

EPA's Clean Air Mercury Rule (CAMR) Web site also provides a reverse chronology of regulatory actions relating to CAMR.

Early 1990s

The Clean Air Act provides that EPA must take several steps before regulating air toxics emissions (such as mercury) from power plants. Deadlines for these steps were specified in a legal settlement of related litigation filed in the early 1990s.

October 1994

EPA enters settlement agreement providing that by November 15, 1995, it would complete its "Utility Air Toxics Study" to Congress; determine whether its is "appropriate and necessary" to regulate power plants under Clean Air Act section 112; and, if so, to issue such regulations by November 15, 2000. The parties subsequently agreed to extend the deadline for completing the Utility Air Toxics study until February 1998. EPA also agreed to solicit additional information from power plants and to use such information for making its ppropriate and necessary determination.

December 1997

EPA analyzed mercury emissions from power plants and other industrial sources, the health and environmental impacts of those emissions and available control technologies. These findings were issued as a "Mercury Study Report to Congress" in December 1997
URL: http://www.epa.gov/airprogm/oar/mercury.html

February 1998

In the "Utility Air Toxics Study" report to Congress, issued in February 1998, EPA focused on power plants, analyzing emissions of toxic air pollutants, including mercury.
Executive Summary (PDF) (28 pp, 109K)
URL: http://www.epa.gov/ttn/atw/combust/utiltox/utilexec.pdf

Volume 1 (PDF) (502 pp, 5 MB)
URL: http://www.epa.gov/ttn/atw/combust/utiltox/eurtc1.pdf

Volume 2 (PDF) (295 pp, 796 K)
URL: http://www.epa.gov/ttn/atw/combust/utiltox/eurtc2.pdf

Errata (PDF) (2 pp, 17K)
URL: http://www.epa.gov/ttn/atw/combust/utiltox/addendum.pdf

Fact sheet (PDF) (5 pp, 30K)
URL: http://www.epa.gov/ttn/atw/combust/utiltox/utilfs.pdf

November 1998

Deadline for EPA to determine whether it is "appropriate and necessary" to regulate power plant emissions under CAA section 112 is extended until December 15, 2000. EPA further agrees to issue proposed and final power plant mercury emission standards by December 15, 2003 and December 15, 2004, respectively.

December 2000

EPA announced its finding that it was "appropriate and necessary" to regulate coal- and oil-fired electric utilities under section 112 of the Clean Air Act. This finding, known as the Utility Air Toxics Determination (PDF) (7 pp, 160K), triggered a requirement for EPA to propose regulations to control air toxics emissions, including mercury, from these facilities by December 15, 2003.
URL: http://www.epa.gov/ttn/oarpg/t3/fr_notices/utilfind.pdf

January 2004

On January 30, 2004, EPA proposed a rule with two basic approaches for controlling mercury from power plants. One approach would require power plants to meet emissions standards reflecting the application of the "maximum achievable control technology" (MACT) determined according to the procedure set forth in section 112(d) of the Clean Air Act. If implemented, this proposal would reduce nationwide mercury by 14 tons or about 30 percent by early 2008. A second approach proposed by EPA would create a market-based "cap and trade" program that, if implemented, would reduce nationwide utility emissions of mercury in two phases. When fully implemented mercury emissions would be reduced by 33 tons (nearly 70 percent). EPA proposed to pursue the cap and trade approach either under Section 111 or Section 112 of the Clean Air Act.

The January 30, 2004 EPA proposed rule also also proposed to revise the Agency's December 2000 finding that is "appropriate and necessary" to regulate utility hazardous air emissions using the MACT standards provisions (section 112) of the Clean Air Act. This action would give EPA the flexibility to consider a more efficient and more cost effective way to control mercury emissions.

EPA also proposed to revise its December 2000 finding that it is "appropriate and necessary" to regulate utility hazardous air emissions using the MACT standards provisions (section 112) of the Clean Air Act. This action would give EPA the flexibility to consider a more cost effective way to control mercury emissions.
URL: http://www.epa.gov/air/mercuryrule/rule.htm

March 2004

On March 16, 2004, EPA proposed a supplement to its January 2004 proposal. This action provided details on the proposed mercury trading program and methodologies for measuring mercury emissions.
URL: http://www.epa.gov/air/mercuryrule/rule.htm

April 2004

To afford the public with an additional opportunity to comment on EPA's proposal, EPA agreed to extend the deadline for issuance of the final power plant mercury rule from December 15, 2004 to March 15, 2005.

December 2004

On December 1, 2004, EPA issued a Notice of Data Availability (NODA) summarizing the modeling analyses presented by EPA and the commenters, and soliciting comment on the inputs and assumptions underlying those analyses. The NODA also sought comment on EPA’s benefits assessment. The public comment period closed January 3, 2005.

March 2005

On March 15, 2005, EPA issued the final Clean Air Mercury Rule, which builds on EPA’s Clean Air Interstate Rule ( CAIR) to significantly reduce mercury emissions from coal-fired power plants. When fully implemented, these rules will reduce utility emissions of mercury from 48 tons a year to 15 tons, a reduction of nearly 70 percent.

The Clean Air Mercury Rule establishes “standards of performance” limiting mercury emissions from new and existing utilities and creates a market-based cap-and-trade program that will reduce nationwide utility emissions of mercury in two distinct phases. In the first phase, due by 2010, emissions will be reduced by taking advantage of “co-benefit” reductions – that is, mercury reductions achieved while reducing sulfur dioxide (SO 2)and nitrogen oxides (NOx) under CAIR. In the second phase, due in 2018, utilities will be subject to a second cap, which will reduce emissions to 15 tons upon full implementation.

May 2005

On May 31, 2005, EPA received two Petitions for Reconsideration of the Clean Air Act Section 112 final rule regarding regulation of mercury and nickel from power plants. One petition was from 14 states and another was from 5 environmental groups and 4 tribes. The petitions requested an opportunity for further public comment on parts of the final Section 112 rule.

June 2005

On June 24, 2005, EPA sent a letter to the petitioners (PDF) (3 pp., 3.69M) to inform them that EPA has decided to initiate a reconsideration process for parts of the Section 112 rule in order to ensure ample opportunity for public comment. EPA will not stay the rule pending the reconsideration process.

October 2005

October 21, 2005 - EPA will reopen for public comment two recent actions governing how the Agency regulates mercury emissions from utilities. The Agency is taking this action in response to petitions filed by several states, tribes, industry, and environmental groups.

EPA will seek additional comment on the March 15, 2005 Clean Air Mercury Rule (CAMR) which established the cap-and-trade approach EPA is using to regulate mercury air emissions from utilities.
In a separate notice, EPA seeks additional comment on portions of its March 15, 2005 rule in which the Agency determined that it was not appropriate or necessary to regulate hazardous air emissions from utilities under Section 112 of the Clean Air Act. (the Section 112 rule)

The comment period for both actions will last until December 19, 2005. EPA will hold a hearing on both actions on November 17, 2005 in Research Triangle Park, North Carolina.

May 2006

May 31, 2006 - EPA issued a final rule to reconsider its March 15, 2005 actions governing how the Agency regulates mercury emissions from utilities:

Its determination that regulation of electric utility steam generating units under section 112 of the Clean Air Act was neither necessary nor appropriate (the section 112 rule); and
The Clean Air Mercury Rule (CAMR)

The Agency took this action in response to petitions filed by several states, tribes, industry, and environmental groups.

February 2008

The United States Court of Appeals for the District of Columbia Circuit in State of New Jersey, et al. v. Environmental Protection Agency (PDF) (18 pp., 51K, about PDF) vacated (i.e., voided) EPA's rule removing power plants from the Clean Air Act list of sources of hazardous air pollutants. At the same time, the court vacated the Clean Air Mercury Rule. EPA is reviewing the court's decisions and evaluating its impacts.