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2014-11-27

Milder ozone pollution season; SA still in violation

Special to The Courier

The 2014 Ozone Season, a period stretching from April through October when air pollution tends to spike, was a milder season than those experienced in recent years. Pending verification by the Texas Commission on Environmental Quality (TCEQ), the season's fourth-highest, eight-hour average ozone concentration measured by a regulatory ozone monitor in the San Antonio-New Braunfels Metropolitan Statistical Area (MSA), was 72 parts per billion (ppb). The federal threshold for ground-level ozone is 75 ppb. Values above this number may cause health issues, particularly for sensitive groups.
The fourth highest, eight-hour average ozone concentration of 2014 is averaged with the fourth-highest concentration from the two previous years' ozone seasons to determine whether an area is in violation of the 2008 U.S. Environmental Protection Agency (EPA) standard for allowable ground-level ozone, the major air pollutant in this region. Attainment of the ozone standard is based on the three-year average of the fourth-highest concentration measured at any one of the area's three regulatory monitors. An area is in compliance with the 2008 standard as long as a three-year average does not exceed 75 ppb.
Although the 2014 season was relatively mild, with its fourth-highest, eight-hour concentration of only 72 ppb, when combined with the fourth-highest concentration of 83 ppb in 2013, and the fourth-highest concentration of 87 ppb in 2012 at the Camp Bullis monitor, the MSA's three-year average is 80 ppb, which violates the EPA's standard threshold of 75 ppb.
In fact, 2014 is the third consecutive year that the area's three-year average of fourth-highest ozone concentrations has surpassed the standard threshold. Because the EPA has not designated areas as nonattainment since 2012, however, the MSA has not officially been deemed as nonattainment and therefore has not been subject to mandatory corrective measures.
If the area's fourth highest eight-hour ground-level ozone concentration is no higher than 72 ppb during the ozone season of 2015, the area could regain compliance with the 2008 ozone standard. Since its fourth highest concentration of 2014 was also 72 ppb, this goal is certainly within reach.
The EPA, however, has made public its intention to set a new, more stringent threshold for ground-level ozone that will fall within the range of 60 to 70 ppb, asserting that the 2008 standard of 75 ppb did not go far enough to adequately protect human health and the environment. An EPA announcement in this regard is expected in December . If the new, lower threshold is set, it would not be possible for the area to meet that new standard unless its ozone concentrations decline significantly.
In the meantime, area governmental agencies and businesses have been working through the Alamo Area Council of Governments (AACOG) to participate in the EPA's Ozone Advance Program, which promotes expeditious improvements in air quality. Participating agencies and industries in our region have implemented numerous voluntary measures that reduce the emission of chemicals that form ozone and they continue to seek additional strategies that will benefit our air quality.
Individuals and employers alike can take steps towards improving air quality. Since ground-level ozone production is strongly linked to transportation, individuals could, for example, carpool, take the bus, brown bag rather than drive out for lunch, combine errands, or avoid heavy traffic congestion. Employers could, for example, offer incentives for carpooling, create flexible schedules that would reduce rush hour traffic, or, to the extent possible, allow some employees to work from home.
Should the MSA be found in nonattainment of the EPA's standards, it will be required to take steps to reduce pollution with the goal of regaining our current clean air status. New or expanding businesses in the area would be required to secure pollution reductions to offset their proposed growth. Also, transportation planners could be required to prove that adding capacity to the roadway system would not increase pollution from cars and trucks in order to qualify for federal highway funds to make the proposed roadway improvements.