POWER December 2012 - 78

MERCURY EMISSIONS
Mercury Regulations Up in the Air
U.S. Environmental Protection Agency efforts to regulate mercury emissions
from coal- and oil-fired power plants have spanned nearly two decades. In
February of this year the agency promulgated the Mercury and Air Toxics
Standards, but changes to the standards continue.
By Brandon Bell PE, KBR Power & Industrial
T
he Mercury and Air Toxics Standards
(MATS) formally impose limitations on
mercury, filterable particulate matter, and
hydrogen chloride emissions from electric generating
units (EGUs) firing coal (including integrated
gasification combined cycle, or IGCC,
facilities), solid oil, and liquid oil. In addition
to a variety of available control technologies to
meet MATS, new technologies that allow measurement
of more minute quantities of mercury
will be necessary to ensure compliance.
Regulatory History
The basis for MATS dates back to two studies
funded by the Environmental Protection Agency
(EPA) and required by the Clean Air Act
(CAA). In 1995, as directed by Congress, the
National Institute of Environmental Sciences
(NIEHS) issued a report detailing the threshold
of mercury exposure below which adverse human
health effects are not expected to occur.
Several years later, the National Academy of
Sciences (NAS) was commissioned to perform
an independent evaluation of the health impacts
from methyl mercury. The results of this study
were finalized and released by 2000, thus satisfying
the CAA Section 112 (n)(1) requirement
to evaluate the hazards to public health from
mercury emissions.
In total, the expected number of units that
will be affected by this regulation is large. There
National Institute of
Environmental Sciences
study commissioned
National Academy of
Science study commissioned
EPA
decision to regulate
mercury
EPA promulgates
Clean Air Mercury Rule
(CAMR)
CAMR vacated
Mercury and Air Toxics
Standards promulgated
u
u
u
u
u
u
are approximately 1,100 coal-fired units and
300 oil-fired units that would need to meet compliance
by three years from the finalization of
this rule. Each facility may request a one-year
compliance extension, which states may grant
on a case-by-case basis.
However, a recent judicial ruling regarding
another key regulation, that found the EPA overstepped
its bounds, could lead to further scrutiny
of the MATS regulation. The decision by
the U.S. Court of Appeals for the District of Columbia
Circuit on Aug. 21, 2012 (EME Homer
City Generation v. EPA, D.C.C. No. 11-1302)
dealt a significant blow to the Cross State Air
Pollution Rule (CSAPR), as it was vacated and
determined that the EPA had regulated beyond
its statutory authority. The court determined the
EPA overstepped its bounds in two key ways.
First, under the " good neighbor " policy, the
EPA has the authority to require upwind states
to reduce their emissions that affect a downwind
state's nonattainment. It was determined
that CSAPR required upwind states to reduce
their emissions by more than the amount that ultimately
affected downwind states. Second, the
court found that states should have been allowed
to reduce their own emissions through a state
implementation plan (SIP). Instead, the EPA
did not give the states this option and enacted
a federal implementation plan (FIP) to reduce
emissions on a state level.
1. History review. Milestones in the regulation of mercury. Source: EPA
A great deal of effort was made by the EPA
to ensure CSAPR would be upheld under legal
review. MATS may succumb to a similar fate,
as multiple parties have filed for review of the
rule by the courts. It should be noted that EPA
regulations have a history of litigation, with
a mixed record of courts upholding them or
rejecting them. At press time, the EPA and intervenors,
including Calpine and Exelon, had
petitioned for a rehearing of the court's Aug.
21 split decision against CSAPR. The court
has ordered 20-page responses to the petition
for rehearing be filed with the court by Oct.
29. The court has no timeline within which to
decide to reject the petition, rehear the case
with another three-judge panel, or hear the
case en banc with all eight judges.
Costs are expected to increase considerably
for implementing the MATS regulation. According
to the EPA's Regulatory Impact Analysis
(RIA), the incremental cost of compliance with
MATS in 2015 will be $9.6 billion per year. As
part of the RIA, the EPA estimated that capital
costs to meet both CSAPR and MATS would
have been $84 billion. Recent cost estimates
by some major utilities suggest that the cost to
comply may be lower than originally estimated.
Even with the vacating of CSAPR and positive
estimates from utilities, final compliance costs
are a moving target, leaving the number of potential
plant closures up in the air.
Mired in Litigation
As a result of the NIEHS and NAS analyses, the
EPA concluded in December 2000 that regulating
hazardous air pollution emissions-specifically
mercury-was appropriate and necessary.
That determination triggered a series of legal
actions that were individually resolved over the
following decade. This process led to the eventual
promulgation of MATS.
After the initial determination that regulating
mercury was appropriate and necessary,
the Utility Air Regulatory Group (UARG)
and Edison Electric Institute (EEI) challenged
this determination in court (UARG v.
EPA, 2001 WL 936363, No. 01-1071, D.C.
Cir. July 26, 2001). The case was dismissed
on jurisdictional grounds.
Mercury regulation was still deemed approDecember
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