United States
Environmental Protection
Agency
Office of Air Quality Planning and Standards
Research Triangle Park, NC 27711
EPA-456/F-98-006
September 1998
The
Regional
Transport
of Ozone
New EPA
Rulemaking on
Nitrogen Oxide
Emissions
EPA tracks emissions of six
principal air pollutants -
carbon monoxide, lead,
nitrogen oxides, particulate
matter, sulfur dioxide,
and volatile organic
compounds. All have
decreased significantly
since passage of the Clean
Air Act in 1970 - EXCEPT
FOR NITROGEN OXIDES.
-------
Facts About IMOX Emissions
New Regional IMOX Transport Rule
Emissions of nitrogen oxides (NOx) discharged into the
atmosphere can pose significant adverse effects on human
health and the environment. In an effort to limit these adverse
impacts, the U.S. Environmental Protection Agency (EPA) issued
a new regulation in
September 1998 specifically
aimed at reducing NOX
Clean Air Act
The Clean Air Act provides EPA and states
with the responsibility to address air
pollution from a variety of sources. EPA
has established National Ambient Air
Quality Standards for six pollutants to
provide protection against harmful levels
that could impact public health and the
environment. These pollutants are often
referred to as the six "criteria" pollutants,
and include carbon monoxide, lead,
nitrogen dioxide, ozone, particulate
matter, and sulfur dioxide. The pollutant
ozone is not emitted directly into the air
but is formed when NOX and volatile
organic compounds (VOC) react in the
presence of sunlight. Ozone occurs at
ground-level and can cause serious human
health and environmental problems. This
new regional NOX transport rule is an
important component of EPA's ozone
reduction program.
emissions.
Nitrogen oxides are a class of
compounds made of nitrogen
and oxygen in varying
percentages. Nitrogen
dioxide, one of six pollutants
tracked nationally, is included
in the family of nitrogen
oxides. NOx are emitted
from high temperature
combustion processes.
Sources include motor
vehicles, electric utilities, and
other industrial, commercial,
and residential sources that
burn fuels. In 1997, over 23
million tons of nitrogen
oxides were emitted into the
air in the United States. An important characteristic of NOX
emissions is that they can be transported long distances and
cause problems far from the original emissions source.
The Clean Air Act (Section 110) provides that each State
Implementation Plan (SIP) must contain provisions preventing
sources within the state from "contributing significantly to
nonattainment problems or interfering with maintenance" in
downwind states. In other words, this provision addresses the
transport problems associated with ozone and pollutants such
as NOX that form ozone.
The Ozone Transport Assessment Group (OTAG), a collection
of the 37 eastern-most states and the District of Columbia,
along with industry representatives and environmental groups,
worked with EPA over a 2-year period to study the ozone
transport problem. The recommendations from OTAG's work
form the basis of EPA's new regional NOX transport rule, signed
in September 1998. The OTAG recommendations focus on
achieving additional reductions of NOx , in order to meet the
National Ambient Air Quality Standards for ozone. The OTAG
recommendations do not identify measures for VOC, although
it is understood that some states may also need to reduce VOC
to achieve the ozone standards.
Affected States
The rule requires 22 states — Alabama, Connecticut, Delaware,
Georgia, Illinois, Indiana, Kentucky, Massachusetts, Maryland,
Michigan, Missouri, North Carolina, New Jersey, New York,
Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee,
Virginia, Wisconsin, and West Virginia, plus the District of
Columbia — to prepare new plans for reducing NOx emissions.
Because NOX includes a
number of different
compounds, the
environmental and health
effects are many and
diverse:
Environmental
and Health
Impacts of NOX Ozone
-------
The overall purpose of
the rule is to reduce
regional transport of
NOx that contributes to
ozone nonattainment in
multiple eastern states,
not to reduce emissions
from a specific source in
a particular state.
22 states and the District of
Columbia to prepare State
reducing NOX emissions.
Rule Provisions
The rule assigns a summertime NOx emissions limit or budget
for each affected state. EPA established the limits by determining
the amount of NOX emissions that would remain in each state
Timeline for complying with Regional NOX Transport Rule
I September 1999 - 22 affected states, plus DC, submit plans to EPA
May 2003 - States put NOX controls in place
September 2007 - States meet overall NOXbudgets
after reasonable, cost-effective control measures were applied.
States are required to have controls in place on larger industrial
sources by May 2003. Along with these controls and other
necessary measures including mobile source controls, states
must meet their overall NOx budgets by September 2007.
The rule does not prescribe how states should reduce emissions
to meet their NOx budget. Instead it allows states the flexibility
to develop customized plans that will most effectively and cost-
efficiently help them meet their reduction goals. Electric
utilities are likely to be one of the major sources targeted for
reductions. OTAG identified utilities as a major source for
achieving significant NOX reductions, and EPA's analysis agrees
with OTAG's recommendations. Emission reductions from
utilities and other large boilers would be more cost effective
in terms of dollars spent per ton of NOx reduced, particularly
when compared to sources that have already reduced emissions
substantially.
Market-based Emissions Trading
Program
As part of developing a cost-effective strategy, EPA developed
a model market-based emissions trading program that states
may use in controlling NOx emissions.
This is a proven, cost-effective technique
for achieving overall emissions reductions
while providing flexibility to affected
sources. The program allows sources that
exceed their emissions reduction
requirements, or that achieve the required
reductions ahead of schedule, to sell
"credits" to other sources that cannot meet their limits. This
type of program already is being successfully implemented for
sulfur dioxide emissions in EPA's Acid Rain Program.
too
Water Quality Deterioration
nutrients used by aquatic plants and
Additional nitrogen accelerates
eutrophication, which leads to oxygen
depletion, and reduces fish and
shellfish populations.
Global Warming
• One member of the NOX family,
nitrous oxide, is a greenhouse gas.
• It accumulates in the atmosphere with
other greenhouse gases causing a
gradual rise in the earth's temperature.
and other adverse changes to plant
Toxic Chemicals
common organic chemicals, and even
ozone, to form a wide variety of toxic
chemicals.
Some of these toxic products may
cause biological mutations.
nitroarenes, and nitrosamines.
Visibility Impairment
dioxide can block the
transmission of light.
Visibility impairment occurs in
urban areas and on a regional
scale in our national parks.
-------
New Transitional Classification
In 1997, EPA issued a new standard based on 8-hour
concentrations of ozone. EPA will designate areas as
"nonattainment" for the 8-hour standard in year 2000. This
NOX transport rule is expected to help areas comply with EPA's
new 8-hour national air quality standard for ozone. Areas that
would normally be classified as "nonattainment" for the 8-
hour standard, but that eventually achieve attainment with
the 8-hour standard as a result of complying with the new
regional NOx transport rule, will be eligible for classification
as "transitional." This means that no or minimal additional
local emission reductions will be required, effectively reducing
the burden and cost associated with local controls. States
must submit implementation plans in 1999 and 2000 that
include control measures necessary to achieve the emissions
reductions required by the new NOX rule. In addition, to qualify
Ozone Transitional Areas Schedule
(Affected by NOX Transport Rule)
September 1999 and May 2000 - States submit plans to EPA
July 2000 - EPA designates areas as transitional for 8-hour ozone standards
May 2003 - States put additional controls in place
September 2007 - States meet overall NOX budgets
for the transitional classification, EPA will determine if the
area has air quality meeting the 0.12 ppm 1-hour ozone standard
by year 2000. This transitional classification will allow areas
to use the benefits of the new NOx transport rule. This rule
helps states achieve the 8-hour ozone standard earlier than
required by the Clean Air Act without having to use costly local
controls.
State Petitions
The Clean Air Act (Section 126) allows downwind states to file
petitions with EPA, requesting EPA to take action to reduce
emissions from industrial sources in upwind states that
contribute significantly to nonattainment in the petitioning
states. In 1997, 8 northeastern states filed petitions identifying
sources of NOX in 22 states and the District of Columbia that
are subject to the new NOX rule, plus a few other states. EPA
will take action in response to these petitions which will be
dependent in part on how states address emission reduction
requirements in the NOX transport rule.
Impacts
EPA anticipates that full implementation of the NOx transport
rule will reduce total emissions of NOX by an average of 28%
in the affected states and the District of Columbia. This rule
will remove about 1.2 million tons of NOx from the air. This
is roughly equivalent to getting 166 million cars off the road.
With regard to attainment status for the new 8-hour ozone
standard, implementation of the regional NOx reduction
program is expected to bring a majority of the new
nonattainment areas into attainment. Cost impacts depend on
the controls put in place by the affected
states and the District of Columbia. EPA
analyses show that reducing one ton of
NOX from electric utility plants costs
about $1500, significantly less per ton
than implementing local controls (which
range as high as $9500/ton). EPA
calculates that the costs of reducing
utility emissions could cause residential
electric rates to increase less than 2
percent. Utility restructuring during this same period, however,
is expected to substantially cut residential electric rates 20-30
percent, thus making the 1 percent increase negligible.
FOR MORE INFORMATION
EPA Office of Air Quality Planning and Standards
Air Quality Strategies and Standards Division
Ozone Policy and Strategies Group, MD-15
Research Triangle Park, NC 27711
919-541-5526
Homepage: http://www.epa.gov/airlinks
Printed on paper that contains at least
20 percent postconsumer fiber.
------- |