Following
8-Hour Ozone
Standard Activities
On March 10, 2009, the US EPA requested that the Court
vacate the existing briefing schedule and hold the consolidated
cases in abeyance. EPA requested the extension to allow time
for appropriate EPA officials that are appointed by the new Administration
to review the Ozone NAAQS Rule to determine whether the standards
established in the Ozone NAAQS Rule should be maintained, modified,
or otherwise reconsidered. EPA further requested that it be directed
to notify the Court and the Parties within 180 days of the Court's
order vacating the briefing schedule of the actions the Agency
has taken or intends to take, if any, with regard to the Ozone
NAAQS Rule, and the anticipated time frame for any such actions.
On September 16, 2009, the EPA announced it would reconsider
the 2008 national ambient air quality standards (NAAQS) for ground-level
ozone for both human health and environmental effects. The Agency
planned to propose any needed revisions to the ozone standards
by December 2009 and issue a final decision by August 2010. On
January 7, 2010, the EPA announced on its web site its proposal
to strengthen the national ambient air quality standards for
ground-level ozone. The EPA's proposal decreases the 8-hour “primary”
ozone standard level, designed to protect public health, to a
level within the range of 0.060-0.070 parts per million (ppm).
EPA is also proposing to establish a distinct cumulative, seasonal
“secondary” standard, referred to as the W126 index, which is designed to protect sensitive vegetation
and ecosystems, including forests, parks, wildlife refuges, and
wilderness areas. EPA is proposing to set the level of the W126 secondary standard within the range of 7-15 ppm-hours.
On August 20, the Agency announced that it will delay its announcement
to on or around the end of October. The proposed revisions result
from a reconsideration of the identical primary and secondary
ozone standards set at 0.075 ppm in March 2008. In May 27, 2008,
health and environmental organizations filed a lawsuit arguing
that the EPA failed to protect public health and the environment
when it issued in March 2008 new ozone standards. The suit was
filed in the U.S. Court of Appeals for the District of Columbia
Circuit by Earthjustice on behalf of a number of environmental
and conservation groups and the American Lung Association. Other
health and environmental organizations involved in the lawsuit
are the Natural Resources Defense Council, Environmental Defense
Fund, National Parks and Conservation Association, and the Appalachian
Mountain Club. Eleven states filed a parallel suit against the
EPA in an effort to overturn EPA's decision on the ozone standards.
The states were Connecticut, California, Delaware, Illinois,
Massachusetts, Maryland, Maine, New Hampshire, New Jersey, New
York, and Rhode Island. Other plaintiffs were the District of
Columbia, the city of New York and Pennsylvania's department
of environmental protection. Besides questioning EPA's decision
to change the health ozone standard from 0.084 ppm to 0.075 ppm,
the suit challenges EPA's decision on ignoring CASAC's recommendation
to establish the cumulative seasonal W126
standard to protect the environment, especially plants. EPA and
White House officials had acknowledged previously that the seasonal
W126 standard had been opposed by the
White House Office of Management and Budget, which oversees government
regulation. Memos in the public record indicate that the issue
was settled after President Bush intervened directly on behalf
of the White House staff.
Historically, it is important to understand some of
the background to the original 8-hour ozone standard. On March
26, 2002, the U.S. Court of Appeals for the District of Columbia
decided on the Petitioners' specific challenges to the original
8-hour ozone air quality standards that remained unresolved.
The Court rejected the argument that the language and reasoning
of their earlier decision determined the outcome of these remaining
claims. Finding the challenged air quality standards neither
arbitrary nor capricious, the Court of Appeals denied the petitions
for review except to the extent the Supreme Court's and their
earlier decisions require further action by EPA. For more information
on the earlier court decision, please go to our summary.
On April 15,
2004, the EPA designated 474 counties as nonattainment for the
original 0.08 ppm 8-hour ozone standard. A map is available
to review the current violating counties. The schedule for implementing the original 8-hour
ozone NAAQS is available for your review. For additional information concerning EPA's implemenation
for the 0.08 ppm 8-hour standard, please go to the Agency's web
page.
The phase 1 final rule sets
forth the classification scheme for nonattainment areas and requirements
for States continued obligations with respect to existing 1-hour
ozone requirements. In the final rule, EPA will separate areas
based generally on their 1-hour ozone design value. A design
value is an air quality measurement used to determine an area's
air quality status in reference to a national standard. (attainment
or nonattainment). This final rule separates 8-hour ozone nonattainment
areas into two categories:
- Areas whose 1-hour ozone
design value is less than 0.121 parts per million fall under
the more general requirements (attainment deadlines 5-10 years
after designation). These areas may be referred to as "Basic
Nonattainment Areas" in public communication materials.
- Areas whose 1-hour design value is greater
than or equal to 0.121 ppm under the more specific requirements
(attainment dates 2007 - 2021). These areas would be further
classified as "marginal", "moderate", "serious",
"severe", or "extreme" based on the severity
of their 8-hour ozone problem.
EPA will revoke the 1-hour standard one year
after the effective date of designating attainment and nonattainment
areas for the 8-hour standard. To avoid "backsliding,"
or losing clean air progress towards attaining the 1-hour ozone
standard, this rule will require the very specific control measures
for the 1-hour standard and included in a state's implementation
plan to stay in place until an area attains the 8-hour standard.
The discretionary emissions reductions in a state's implementation
plan would also remain but could be revised or dropped based
on modeling demonstrating that it would be appropriate. Phase
2 of the final 8-hour ozone implementation rule will address,
among other things, reasonably available control measures, reasonably
available control technology, attainment demonstrations and modeling
requirements, and will be issued in the next several months.
In the June 1998 issue of Environmental Science
& Technology (32(11):276A-282A), an article about the
"piston" effect discusses why the 8-hour ozone standard
may be difficult to attain. The EPA has confirmed that its emission
reduction modeling results are showing inconsistencies. In addition,
a paper has just been published in the prestigious journal, Atmospheric
Environment, that discusses the difficulty in applying enough
emission reductions to attain the new ozone standard. Another
modeling article has been submitted to another peer-review journal
that discusses similar difficulties. Clearly, the "piston"
effect appears to be interfering with attaining the 8-hour ozone
standard. With continuing research on the "piston"
effect and its ramifications, it may become apparent to the EPA
and Congress that action may have to be taken prior to the planned
attainment deadline years to modify the form of the 8-hour ozone
standard. Alternative forms that will protect the public's health,
at the same level as the 8-hour standard, are available. For
more information on the "piston" effect, please see
the Table of Contents web page.
On July 5, 2000, EPA reinstated the 1-hour standard
for ozone in nearly 3000 counties, where the standard had been
revoked since 1998. The reinstatement of the 1-hour standard
affects some areas that had been designated as "attainment"
for EPA's 1-hour ozone standard and some that formerly were designated
as "nonattainment," but where monitors showed clean
air for 3 consecutive years. According to the Agency, the reinstatement
creates a safety net for nearly 3,000 counties across the country,
while EPA was waiting for the U.S. Supreme Court decision on
its 8-hour standard.
On July 22, 1999, the U.S. EPA issued a response to an article written in the Winter/Spring NARSTO
News. The article summarizes items from a critical review paper
by Parrish and Fehsenfeld, which expresses concerns about the
integrity of ambient ozone measurements, using the EPA-approved
UV absorption monitoring method. The potential measurement errors
cited were calibration uncertainties, ambient interferences,
and anomalous operating conditions. The EPA has agreed that there
is a need for additional field intercomparisons of the UV technique
with other ozone measurement techniques, particularly during
conditions typical of ozone exceedances, to better define the
scope and impact of any potential UV ozone measurement uncertainties.
In another development, it appears that the CASTNet ozone monitors,
located in rural areas across the U.S., were not properly calibrated
and therefore, the EPA is currently planning on not using the
data collected from these monitors to identify nonattainment
designations for the 1997-1999 period. On the other hand, EPA's
Office of Research and Development is still using the CASTNet
data for "trends" purposes.
