Mention the word "ozone" and many people think of the ozone layer, the part of the atmosphere that deflects ultraviolet rays.
Closer to the ground, ozone is the main ingredient in smog. The air pollutant is caused by manmade chemical reactions and can cause respiratory issues. Ozone is typically higher between April 1 and Oct. 31.
Experts say the Austin area meets all federal air quality standards but has struggled to stay under the accepted ozone levels.
A group of local governments known as the Central Texas Clean Air Coalition has spent years working on voluntary programs to reduce air pollution. In April the coalition received the 2014 Clean Air Excellence Award from the Environmental Protection Agency for its efforts.
Officials say the work to improve Austin-area air is ongoing. The area is still close to the federal ozone limit, and the EPA could tighten restrictions later this year.
"Our ozone levels have continued to go down year after year even with our continued growth," Round Rock Mayor Alan McGraw said at an ozone season kickoff event April 8. "It's very important in my mind that we continue following the path that was already started and continue on that path because nonattainment [of ozone reduction] will have serious economic development implications."
Acceptable levels of ozone
Every five years the EPA is required to review the National Ambient Air Quality Standards as part of the Clean Air Act.
In 2008 the EPA lowered the national eight-hour ozone average standard from 85 to 75 parts per billion of total gas in the air.
How the EPA measures ozone is that cities such as Austin can exceed the standard three days a year, said Andrew Hoekzema, air quality program specialist for the Capital Area Council of Governments.
"They use the fourth-highest readings each year and average that across three years," he said. "If the three-year average of the fourth-highest [readings] is above 75 parts per billion, the area is considered in nonattainment."
If the EPA declares an area is in nonattainment, the state must enact a State Implementation Plan to meet the standards.
Under nonattainment, securing federal grants would become more complicated, Hoekzema said.
"The region's transportation plan is required to be consistent with its air quality plan," he said. "There's a cap on road emissions, and the transportation plan must stay under the cap."
Meeting the standards
The CAPCOG coalition comprises Bastrop, Caldwell, Hays, Travis and Williamson counties and 13 city governments, including the cities of Georgetown, Hutto, Pflugerville and Round Rock.
From 2008 to 2013, the coalition enacted the Eight-Hour Ozone Flex Plan.
The coalition secured voluntary emission reduction commitments from local government entities on items such as reducing commutes and increasing vehicle fleet efficiency measures, according to CAPCOG (see sidebar).
"If we want to continue to grow in this region and continue with the success we've had, then in my mind it is very important that we stay out of nonattainment," McGraw said. "I'd rather do that voluntarily with programs and policies that we put in place as a region as opposed to waiting to go to nonattainment and having the federal government tell us how they want us to do it."
The award-winning plan helped to bring the average area readings down from 74 to 73 parts per billion as of 2013, Hoekzema said.
The flex plan has since evolved into a newer version, the Ozone Advance Program, that expands on what types of emission-reduction commitments are possible, Hoekzema said.
"The region is poised to be in a position to meet a new ozone standard if it is set as high as 70 parts per billion by 2018 but would be challenged to meet one as low as 65 parts per billion," according to the program's action plan.
Meanwhile the EPA had not completed its review of the 2008 standards by the end of 2013. It is roughly halfway through the process, EPA Region 6 spokesman Joseph Hubbard said.
Pharr Andrews, city of Austin environmental. program coordinator, said the EPA could issue stricter standards by December.
Neil Carman, clean air program director for the Lone Star Chapter of the Sierra Club, said the organization advocates stricter standards for vehicle emissions and industrial smokestacks.
The Sierra Club supports telecommuting, carpooling, public transportation and bicycle riding as ways to address the issue.
Carman called the federal 75 parts per billion standard inadequate to protect human health and said the standard should not exceed the 70 parts per billion that was recommended by the EPA's advisory group.
"Ozone in terms of health effects is something that is affecting a significant portion of our population—children, senior citizens and people with chronic respiratory problems all can suffer from health effects from high ozone, which we from time to time experience," Hoekzema said. "[Our goal is not only] stay out of [a] formal nonattainment designation, but also to reduce ozone levels overall."