Summary of the USEPA Clean Air
Mercury Rule
(Federal Register- January
30, 2004)
Click to See Council's Position on the
Rule
On March 15, 2005, the United
States Environmental Protection Agency (USEPA) issued the Clean
Air Mercury Rule, the nation’s first-ever rule to regulate
mercury emission from coal-fired power plants. The new regulations
requires reductions in mercury (Hg) for new or existing coal-fired
power plants and nickel (Ni) for new or existing oil-fired power
plants. USEPA predicts that the new rule would cut mercury emissions
forty percent by 2010 and seventy percent by the year 2018.
Outlined below is a brief summary of the rule prepared by the
staff of the Adirondack Council. Readers are encouraged not to
rely solely on this summary. More information and links to the
text of the rule as published in the Federal Register and the
technical documents upon which it relies are all accessible through
USEPA's website at http://www.epa.gov.
Background
Coal and oil-fired utilities
emit a wide variety of metal, organic, and inorganic Hazardous
Air Pollutants (HAP) depending on the type of fuel combusted.
Exposure to mercury (Hg) and Nickel (Ni), both of which are HAP,
above certain thresholds has been demonstrated to cause adverse
health effects.
In 1998, USEPA issued a Report
to Congress on its study of HAP from electric utilities. The
Utility Report had examined 67 of the 188 HAP listed in the Clean
Air Act, which USEPA believed to have the greatest potential
for adverse health effects from utility emissions. Mercury was
identified to be of greatest concern. In December 2000, USEPA
issued findings that major coal-burning utilities are the single
largest source of man-made emissions of Hg in the United States,
and that there was a plausible link between methyl mercury concentrations
in fish and Hg emissions from coal-fired utilities. The Agency
further found that it was appropriate and necessary to regulate
those emissions as hazardous air pollutants under Section 112
of the Clean Air Act (CAA).
The Clean Air Mercury Rule
Under the new rule, USEPA revised
its earlier finding that it was necessary to regulate mercury
emissions under Section 112. USEPA contends that decision was
based, in part, on the assumption that there was no other appropriate
means to regulate these emissions, but for the standards found
in section 112. USEPA now asserts that Hg emissions can be effectively
reduced by a cap and trade approach under section 111(CAA) ,
and it is not necessary to employ the Maximum Achievable Control
Technology (MACT) approach in section 112, which would have required
EPA to set plant by plant emission standards for existing and
new plants.
The distinctions between section
111 and 112 of the Clean Air Act and the Agency's authority under
each section consume a considerable portion of USEPA analysis
in the posted regulatory notice. In the alternative, USEPA argues
that it has the authority to adopt a cap and trade approach for
existing plants, even if they do not revise their earlier finding
that it is necessary to regulate these emissions under the authority
of Section 112. In a lengthy analysis, USEPA determines that
a cap and trade approach is acceptable even under the language
of section 112. One benefit from that approach -according to
USEPA-is that a cap and trade program under section 112 would
allow a national program that would not be dependent on each
state modifying its own state implementation plan. USEPA states
that a national program cap and trade program would be more predictable
and economical to administer as well.
Regardless of how it proceeds
on existing coal-fired facilities, USEPA intends to regulate
nickel emissions from all oil-fired utilities and nickel and
mercury emissions from new coal-fired utilities on a plant by
plant basis, using an output-based standard. The regulation of
nickel emissions will be based, for example, on a floor of the
average performance of a particular pollution control device--
the electrostatic precipitator (ESP).
USEPA defends its decisions in
part, on the finding that the Agency cannot currently quantify
whether adverse health effects occur in communities around these
facilities, nor can it quantify the relative contribution of
these facilities to any health problems or to the concentrations
of mercury in fish. USEPA estimates that U.S anthropogenic Hg
emissions account for 3% of the global total and that coal-fired
utilities account for 1% of total global emissions.
USEPA also considered the fact
that existing coal-fired utilities combustion units are usually
designed to specifically burn one coal rank (type), which is
usually dictated by what type of coal is readily and economically
available in the region. Within the specific coal ranks, the
Hg content can vary significantly. The differences in facility
design, according to USEPA, make a retroactive output-based emission
standard more difficult.
USEPA also finds that there will
be a co-benefit from a separate new rule regulating sulfur and
nitrogen emissions from coal-fired plants, in that the same pollution
control devices that are effective on those pollutants are also
somewhat effective for mercury. USEPA is basing its first phase
of mercury cuts on the assumption that the use by coal-fired
utilities of fabric filters and ESP's (the most common pollution
control equipment) to control sulfur and nitrogen emissions will
result in approximately a 40% reduction in mercury emissions
as well. USEPA proposes that the first cap for mercury reductions
in 2010 would be equivalent to a 40% reduction from current emission
levels.
The Agency also maintains that
the technology for more efficient mercury removal is not readily
available at this time. USEPA specifically takes issue with a
2003 report from the environmental organization, Environmental
Defense, that the experience gained from the regulation of municipal
waste incinerators and medical waste incinerators indicates that
coal-fired utilities can achieve 90% mercury emission reductions.
USEPA says that the report underestimates the variability of
Hg in different coals and the technical differences between the
types of facilities. USEPA therefore asserts that a second phase
of controls, which it proposes to be a 70% reduction from existing
levels, should be delayed until 2018. The Agency believes that
2018 is a reasonable target date that will be technology-forcing
as companies seek early controls that can free up credits to
sell to other plants.
The Agency does not expect "hotspots"
to develop from trading. The forms of mercury that are most likely
to fall close to the stack, and thus create local pollution problems
according to USEPA, are also the mercury types that are most
readily captured by pollution equipment commonly used for the
control of sulfur and nitrogen emissions.
USEPA is proposing a cap and
trade program for Hg in which one pollution credit would equal
the right to emit one ounce of mercury. As in the acid rain program,
mercury allowances would be distributed among major coal-fired
utilities based on their output for a baseline year. Hg emissions
would be counted on a rolling 12 monthly average. Each of these
allowances will have a discrete serial number and all coal-fired
facilities will be required to install continuous emission monitoring
(CEM) devices.
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