Controlling Power Plant Emissions: Chronology
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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.
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 appropriate and necessary determination.
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.
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)
1 (PDF) (502 pp, 5 MB)
2 (PDF) (295 pp, 796 K)
Errata (PDF) (2 pp, 17K)
sheet (PDF) (5 pp, 30K)
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.
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.
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. Learn about and review the public comments EPA received on the proposed and supplemental Clean Air Mercury Rule.
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. Learn about and review the public comments EPA received on the proposed and supplemental Clean Air Mercury Rule.
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.
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.
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.
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.
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 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)
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.
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.
We are currently awaiting a response from the U.S. Supreme Court concerning petitions for certiorari filed late last year by EPA and the Utility Air Regulatory Group (UARG), seeking review of the D.C. Circuit’s vacatur of the Section 112(n) Revision Rule and the Clean Air Mercury Rule (CAMR).