- In another step to ensure that Americans breathe cleaner air,
EPA has issued guidance for states to use in recommending areas
to be designated as attainment and nonattainment for the 8-hour
- The non-binding guidance outlines how states should determine
appropriate boundaries for the attainment and nonattainment areas.
The term "nonattainment" means an area has had, or has contributed
to, nearby ozone violations over a three-year period - generally
1997 through 1999.
- Under the process EPA outlined today, the soonest designations
could become effective is early 2001. EPA will ensure that state
and local governments have ample time to comply with any requirements
as the Agency decides when to finalize designations and make them
- EPA issued the 8-hour ozone standard in 1997. Two laws - the
Clean Air Act and the Transportation Act for the 21st
Century - require EPA to designate areas this year as attainment
or nonattainment for the 8-hour standard.
- In general, areas with monitors showing violations of the 8-hour
level during 1997-1999 would be designated as nonattainment. Surrounding
counties contributing to those violations should be included in
the nonattainment area.
- Today's guidance encourages states to base attainment and nonattainment
area boundaries on Metropolitan Statistical Areas or Consolidated
Metropolitan Statistical Areas. These boundaries will ensure that
states consider population density, traffic and commuting patterns,
commercial development and area growth when recommending areas
for attainment and nonattainment designation.
- The guidance also recommends that if an area to be classified
as nonattainment for the 8-hour standard also has been designated
as nonattainment for the 1-hour ozone standard, the boundary would
be the larger of : a) the current consolidated/metropolitan statistical
area boundary; or b) the 1-hour nonattainment area boundary.
- States may suggest different boundaries. However, states must
provide a rationale for any boundary changes and explain how they
meet Clean Air Act requirements.
WHAT A NONATTAINMENT DESIGNATION MEANS
- Once nonattainment designations take effect, they become an
important component of state and local governments' efforts to
control ground-level ozone, or smog.
- The Clean Air Act requires state and local governments to take
steps to reduce smog-causing pollution in nonattainment areas.
Among these is a measure known as "transportation conformity,"
which means local transportation and air quality officials must
coordinate planning to ensure that transportation projects, such
as road construction, are consistent with air quality goals.
- Once designated, nonattainment areas also are subject to new
source review requirements, to ensure that new
and modified sources of pollution do not impede progress toward
- Once nonattainment areas are designated, states must develop
plans demonstrating how their nonattainment areas will meet the
ozone standard. These plans are known as state implementation
plans, or SIPs.
HOW THE DESIGNATIONS PROCESS WILL WORK
- States will have until June 30, 2000, to recommend to EPA areas
that should be designated as nonattainment. EPA will review and
consider those recommendations, and respond to the states by late
- EPA will not make final designations until at least four months
after it responds to states' recommendations. States will have
the opportunity during this time to comment on EPA's responses.
- Based on this schedule, EPA could not make final designations
before late December. EPA will set an effective date when it makes
the final designations. The earliest designations could become
effective would be early 2001.
- Indian tribes that have their own air quality programs may submit
their own recommendations for designations; however, they are
not required to do so. Because air quality data is lacking in
some tribal areas, EPA will work with tribes to determine the
- Two laws require EPA to designate areas as attainment or nonattainment
for the 8-hour ozone standard. Those laws are the Clean Air Act
and the Transportation Act for the 21st Century (known
as TEA-21). EPA is required to designate attainment and nonattainment
areas by July 2000.
- In May 1999, and as modified in October 1999, the U.S. Court
of Appeals for the D.C. Circuit remanded 8-hour ozone standard
and issued an opinion limiting the manner in which EPA can implement
it. However, the court affirmed EPA's
authority to make designations.
- The federal government has asked the U.S. Supreme Court to review
aspects of the D.C. Circuit decision on the 8-hour ozone standard.
The Court of Appeals did not question the need for the new standard
or the science behind it. That standard, based on 8-hour averages
of ozone rather than the previous 1-hour average, reflects a more
realistic measure of people's exposure and is more protective
of public health.
- EPA provided initial guidance on designations in June 1999.
Today's guidance supplements that information.
OZONE AND HEALTH
- Ground-level ozone, the primary component of smog, is formed
when emissions of nitrogen oxides and volatile organic compounds
react in the sun. Sources for these emissions include power plants,
factories, motor vehicles, chemical solvents and consumer products.
- When inhaled - even at very low levels - ground-level ozone
can: cause acute respiratory symptoms, such as coughing and discomfort
in the throat and chest; aggravate asthma; reduce lung function;
inflame and damage lung tissue; and impair the body's immune response
to respiratory infection.
- Children - especially those with asthma - are at the greatest
risk from ozone pollution. During the summer, when concentrations
of ground-level ozone are highest, children playing outside are
most likely to experience respiratory symptoms and effects.
FOR MORE INFORMATION
- Today's guidance may not be immediately available on EPA's Internet
site, depending on the status of the site at this time. For more
information about today's guidance, call Sharon Reinders at the
Office of Air Quality Planning & Standards, 919-541-5284.
- To read the June 1999 guidance, go to the EPA's World Wide Web