POWER November 2010 - 24

Steven F. Greenwald
Angela Neville, JD
M
EPA's Mercury Rule:
Another Incarnation Coming
uch like the shape-shifting substance it regulates,
the mercurial enforcement rule that governs mercury
emissions from coal-fired power plants has changed
unpredictably several times in recent years. During the past
decade, the rule has undergone a number of major revisions
driven by political pressures from environmentalists, public
health entities, electric utility advocacy groups, and other interested
stakeholders.
Mercury's Impact on Human Health
The U.S. Environmental Protection Agency (EPA) is mandated to
regulate mercury emissions based on concerns about the contaminant's
effect on human health. Exposure to mercury can occur
from breathing contaminated air and ingesting contaminated
water and food. Mercury exposure at high levels may damage
the brain, kidneys, and developing fetuses, according to the U.S.
Agency for Toxic Substances and Disease Registry.
The most common mercury exposure route for the majority of
people is not through inhalation of air-borne fumes but, rather,
through the consumption of fish and shellfish that contain large
quantities of mercury. After mercury is released into the environment
as part of the emissions from coal-fired power plants, it
enters the air and then rains down into streams and other water
bodies, where it can be ingested by microscopic organisms that
convert it into methylmercury. This form of mercury can accumulate
in the tissue of fish and other organisms. Currently, the U.S.
Food and Drug Administration has set the maximum permissible
level of methylmercury in seafood at 1 part per million.
The Mercury Rule's Recent Roller Coaster History
In February 2008, the U.S. Court of Appeals for the District of Columbia
Circuit threw out the EPA's Clean Air Mercury Rule (CAMR).
The 2005 CAMR required coal- and oil-fired power plants to cut
their mercury emissions by 70% by 2018 and created a national
emissions trading program to cut industry compliance costs.
A companion rule issued at the same time as CAMR reversed
the 2000 Clinton-era determination that utility emissions of mercury
and other hazardous air pollutants (HAPs) must be regulated
under the maximum achievable control technology (MACT) standard,
which is a much stricter requirement than the 70% reduction
required under CAMR.
Once the appeals court's order went into effect in 2008, the
Clinton EPA's finding was reinstated as the law governing mercury
emissions, pending the EPA developing a new MACT standard. In
February 2009, the Obama administration's EPA asked the U.S.
Supreme Court to dismiss a petition brought by the Bush EPA in
2008 asking the high court to review and overturn the U.S. Court
of Appeals' 2008 ruling that struck down CAMR.
EPA's Current Efforts to Develop a New Rule
Now the EPA is working on a new air toxics emissions standard for
power plants under the Clean Air Act (Section 112), consistent
24
with the D.C. Circuit's opinion regarding CAMR. The EPA intends
to propose air toxics standards for coal- and oil-fired electric
generating units by March 10, 2011, and finalize a rule by November
16, 2011, as ordered under the court's consent decree.
On December 24, 2009, the EPA approved an Information Collection
Request requiring all U.S. power plants with coal- or oilfired
electric generating units to submit emissions information
The EPA intends to propose air
toxics standards for coal- and
oil-fired electric generating units
by March 10, 2011, and finalize
a rule by November 16, 2011.
for use in developing the agency's proposed air toxics emissions
standards.
Based on mercury controls in place or proposed for power
plants, the new federal standard is likely to be in the range of
85% to 90% mercury removal, according to many industry analysts.
If the EPA moves to adopt the MACT standard for utility
HAPs, including mercury, that will probably mean that all U.S.
coal-fired plants will either have to install scrubbers and particulate
controls by 2015, dramatically cut their hours of operation,
or shut down.
Seeking Certainty in Mercury Regulation
As quirky as quicksilver, the mercury rule has moved all over
the regulatory landscape in recent years and left electric utilities
guessing what steps they might need to take in order to
comply. Now electric utilities once again are waiting to see what
the latest version of the rule will be. In particular, power companies
seeking to build new coal-fired units have to deal with
the hurdle of changing laws driven by the political agendas of
diverse groups. Many projects are on hold until utility management
has some certainty about what their facilities' compliance
obligations will be under the new rule that is scheduled to go
into effect in late 2011.
Fortunately, some utilities, such as Southern Co., are finding
that one possible cost-effective approach to complying with the
upcoming revised mercury rule may be to use " co-benefits " from
air quality control systems already in service that are designed
to remove other pollutants (see " Determining AQCS Mercury Removal
Co-Benefits " in our July 2010 issue).
The U.S. electric power industry needs regulatory predictability
in order to operate efficiently. Hopefully, once the EPA takes
action next year, its new mercury rule will allow utilities to act
with certainty as far as implementing effective mercury control
measures to protect human health and the environment. ■
-Angela Neville, JD, is POWER's senior editor.
www.powermag.com
POWER| November 2010
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POWER November 2010

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