Amended air quality plans now under federal
review
As federal compliance dates approach, the TCEQ searches for
more ways to reduce ozone levels, and the governor proposes an
extended deadline for the Houston area. Meanwhile, EPA eyes even
tougher ozone standards.
In this story:
Progress Continues
Study Findings Under Review
Sidebar: New Technology Could Aid Pollution
Detection
Pending federal approval, the TCEQ is preparing to institute
plans for deeper emission reductions in the state's two largest
metropolitan areas. The nonattainment areas of
Houston-Galveston-Brazoria and Dallas-Fort Worth are working to
curb emissions to satisfy federal air quality standards for
ozone.
Eight counties in the Houston area and nine counties in the
Dallas-Fort Worth area face a deadline of June 2010 to comply with
the federal ozone standard of 85 parts per billion (ppb) in any
8-hour period. Any ozone monitor measuring average levels higher
than that on four or more days in a year constitutes a
violation.
In May, the TCEQ adopted revisions to the State Implementation
Plan, a document detailing Texas' clean-air strategies, and sent
the proposals to the Environmental Protection Agency for
review.
Along with the SIP submission to EPA, Gov. Rick Perry sent a
request to change Houston's nonattainment classification from
"moderate" to "severe" and to extend the attainment deadline. Perry
proposed giving the highly urbanized area until June 2019 to
demonstrate attainment.
Noting that the region has a "huge population, one of the
largest and most comprehensively controlled petrochemical complexes
in the world, and a subtropical climate," Perry said that Houston
and its neighboring counties face a monumental task in meeting the
8-hour standard.
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In a Nutshell: SIP
Revisions
New control measures for the counties of Harris, Galveston,
Brazoria, Chambers, Fort Bend, Liberty, Montgomery, and
Waller
- New and existing controls on VOC emissions from marine sources
and storage tanks;
- requirements for certain marine fuels to meet the Texas Low
Emission Diesel standards; and
- additional programs sponsored by local governments.
New control measures for the counties of Dallas,
Tarrant, Collin, Denton, Ellis, Johnson, Kaufman, Parker, and
Rockwall
- Further emission reductions from major sources of NOx, such as cement kilns and electric generating
facilities;
- reduced emissions from minor sources of NOx, such as engines;
- additional programs sponsored by local governments; and
- emission reductions from rich-burn compressor engines in 33
East Texas counties.
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"Modeling indicates that not even a complete shutdown of the
Houston Ship Channel industrial area would bring about sufficient
reductions" for the region to attain the ozone standard in 2010,
the governor wrote.
Soon after, EPA announced it might revise the standards for
measuring ozone for the first time since 1997. EPA is accepting
public comments until early October on setting the ozone standard
within a range of 70-75 ppb. Recommendations from the states, drawn
from 2006-2008 monitoring data, are due to EPA in June 2009.
TCEQ officials said EPA's proposed new standard would place most
mid-size to major cities in Texas in nonattainment for ozone.
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Progress Continues
Looking at the big picture, TCEQ Chief Engineer David
Schanbacher says Houston and Dallas-Fort Worth have made
substantial progress in air quality the last 15 years—all
while experiencing economic and population growth.
In fact, if EPA's 1-hour ozone standard were still in effect,
Dallas-Fort Worth would have reached attainment in 2006, he says,
predicting that the region will satisfy requirements for the
current 8-hour standard in 2010.
As for Houston, the TCEQ is "moving forward expeditiously" with
stronger regulations addressing the ozone precursors of nitrogen
oxides (NOx) and volatile organic
compounds (VOCs), he says.
Schanbacher pointed out that the two urban areas have different
emissions profiles and therefore require different solutions.
Ozone levels in the Dallas-Fort Worth area stem primarily from
mobile sources, such as cars and trucks. With Houston, "our
strategies have to be comprehensive enough to encompass not only
mobile sources but also broad-based industrial activities, plus a
complex situation with the meteorology in the Gulf Coast area," he
says.
Under the federal Clean Air Act, mobile sources are regulated by
EPA and not by states or local governments. Even so, TCEQ officials
expect that both regions will benefit from the expansion of the
Texas Emissions Reduction Plan, which issues grants to upgrade or
replace older, higher-polluting diesel vehicles and equipment, and
another state program that repairs or replaces aging gasoline
vehicles (see article on
new legislation).
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Study Findings Under Review
Yet to be seen are the results of the Texas Air Quality Study
II. Its findings are expected to become an important component in
formulating future air quality plans.
The multimillion-dollar research project is being carried out by
TCEQ staff along with scientists from institutions of higher
education and federal and state agencies.
The goal is to better understand the role of different emission
sources in the formation of ground-level ozone. The study will help
document the transport, or movement, of pollutants into and within
Texas. It will also produce more accurate estimates of ozone
precursors, new pollutant data for all of East Texas, and improved
computer models for simulating ozone pollution.
During the field study, held from mid-August to mid-September
2006, 141 sites in the eastern half of Texas reported their hourly
emissions of NOx, VOCs, and sulfur dioxide
(SO2) from predetermined industrial
sources. From that, an hourly point source emissions inventory was
assembled for analytical projects.
This data-collection aspect of the study targeted emission
sources that are subject to state rules for highly reactive VOCs,
as well as NOx and SO2 sources equipped with continuous emission
monitors. Sources near air monitoring sites were included, too.
Researchers and TCEQ staff are continuing to analyze not only
the data from the special inventory but also the data collected
from special monitoring locations and aircraft missions.
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New Technology Could
Aid Pollution Detection
The TCEQ is conducting the first study by a U.S. regulatory
agency of a new monitoring technology at industrial sites.
This summer, the TCEQ took temporary possession of an advanced
remote sensing system that uses infrared and ultraviolet lasers to
measure emissions downwind from sources of volatile organic
compounds (VOCs).
The equipment, operated by a United Kingdom company, performs
differential absorption lidar (DIAL) measurements on industrial
emission sources. This method has been used in Europe for two
decades to get readings from industrial sources that are difficult
to measure with conventional sampling techniques.
The study, funded in part with a $200,000 grant from the
Environmental Protection Agency, focused on VOC emission sources at
cooperating industrial sites in Texas City.
DIAL measurements were conducted for five weeks during July and
August. At the same time, infrared-gas imaging cameras were used in
aerial and ground observations.
The purpose of the study was to measure actual emissions from
difficult-to-measure sources and then compare the data to results
obtained with standard methodologies. Preliminary data will be
available this fall.
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