2010 Progress Report - International Joint Commission

The United States has various
programs to ensure that air quality is
not signifi cantly degraded by the
addition of air pollutants from new or
modifi ed major sources. The Clean Air
Act requires major new stationary sources of air
pollution and extensive modifi cations to major existing
stationary sources to obtain preconstruction permits.
The permitting process is called New Source Review
(NSR) and applies both to areas that meet the
National Ambient Air Quality Standards (NAAQS)
(attainment areas) and areas that exceed the NAAQS
(nonattainment areas). Permits for sources in attainment
areas are prevention of significant deterioration (PSD)
permits, while permits for sources located in
nonattainment areas are nonattainment area
(NAA) permits.
UNITED STATES
PSD permits require air pollution controls that
represent the best available control technology
(BACT). BACT is an emission limitation based on
the maximum degree of reduction of each pollutant
subject to regulation under the Clean Air Act. BACT
is determined on a case-by-case basis and considers
energy, environmental and economic impacts.
NAA permits require the lowest achievable emission
rate (LAER). BACT and LAER must be at least as strict
as any existing New Source Performance Standard
(NSPS) for sources. One important difference between
NSR permits and the NSPS program is that NSR is
applied on a source-specifi c basis, whereas the
NSPS program applies to all sources nationwide.
The PSD program also protects the air quality
and visibility in Class I areas (i.e. national parks
exceeding 6,000 acres and wilderness areas
exceeding 5,000 acres). The federal land management
agencies are responsible for protecting air qualityrelated
values, such as visibility, in Class I areas by
reviewing and commenting on construction permits.
The Clean Air Act established the goal of improving
visibility in the nation’s 156 Class I areas and returning
these areas to natural visibility conditions (visibility
that existed before human-caused air pollution);
the 1999 Regional Haze Rule requires that states
reach that goal by 2064. In July 2005, the EPA
fi nalized amendments to the Regional Haze Rule.
These amendments require the installation of emission
controls, known as best available retrofi t technology
(BART), on certain older, existing combustion sources
within a group of 26 source categories, including
certain EGUs that cause or contribute to visibility
impairment in Class I areas. Many of these older
sources have never been regulated, and applying
BART will help improve visibility in Class I areas.
Most of the regional haze SIPs have been submitted,
and controls to satisfy the BART requirements are to
be operational no later than fi ve years after the SIP
is approved.
The fi rst planning period establishes an assessment
of expected visibility conditions in 2018. The SIPs are
revised every 10 years, and states revise their visibility
goals accordingly to ensure that reasonable progress
is being made to achieve natural visibility conditions.
There is also a reporting check every fi ve years, in
which states report their interim progress toward
reaching the goals. Additional information on the
EPA’s Regional Haze Program can be found at
.
Figure 10 shows the annual average standard
visual range within the United States for the period
2004–2008. “Standard visual range” is defi ned as
the farthest distance a large dark object can be seen
during daylight hours. This distance is calculated
using fi ne and coarse particle data from the IMPROVE
network. Increased particle pollution reduces the
visual range. The visual range under naturally
occurring conditions without human-caused pollution
in the United States is typically 45 to 90 miles (75 to
150 km) in the east and 120 to 180 miles (200 to
300 km) in the west. Additional information on the
IMPROVE program and visibility in U.S. national
parks can be found at http://vista.cira.colostate.edu/
improve/.
Commitments
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