COLUMBIA -- Impending, tougher ozone standards could hurt economic development, especially in Columbia and Greenville, and even reach to every corner of the state, South Carolina air-quality officials say.
The federal Environmental Protection Agency announced July 11 that it is considering further restrictions on the pollutant across the nation.
Depending on which of the tougher standards the EPA adopts, the effects in South Carolina could range from more ozone-alert days to pressures on industries to buy expensive emission-control equipment, two regulators at the state Department of Health and Environmental Control said last week.
Ozone comes largely from vehicle engine emissions and boilers in large industries, especially utilities.
"It's going to significantly affect a large portion of South Carolina," said John Litton, the state's assistant director for air quality.
But many states east of the Mississippi River also would be hit hard.
Robert Brown, director of DHEC's division of air planning development, said the new standards would require large industrial construction projects to undergo more rigorous reviews of their impact on ozone production.
That could delay or block some projects.
"That gets to jobs and people's welfare," Litton said.
Residents of metropolitan Columbia and Greenville likely would experience more "yellow" and "orange" ozone-alert days, they said.
"Yellow" alert days are considered moderate, meaning people who are unusually sensitive to ozone should consider limiting prolonged outdoor exertion.
"Orange" alert days -- which Brown said are rare in South Carolina -- are considered unhealthy for sensitive groups. Active children and adults and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion on those days.
Yellow and orange are the second and third on DHEC's five-step air quality index, which ranges from green (good) to violet (very unhealthy).
The regulators stressed the EPA's proposed rule change would not mean the air is dirtier -- just that air-quality standards continue to grow more strict.
Air quality in this state is better than it has been in 20 years, Litton said, "but the EPA continues to lower the standard ... because science keeps learning ... about the health effects of ozone."
The federal agency is weighing whether to toughen the standard by anywhere from 12 percent to 25 percent, said Brown, who is responsible for implementing air quality standards in the state.
It might cut the current standard for the pollutant to 0.07 parts per million from the current 0.08 parts, they said.
But the standard could be dropped to as tough as 0.06. If that standard becomes law, all of S.C.'s 16 air monitoring sites would have readings that exceed that level, Brown said.
At the less severe standard, the metropolitan area around the capital city and the Interstate 85 corridor, including metropolitan Greenville, would have the toughest challenge.
If the stronger restriction is adopted, the Sumter, Florence and Charleston areas also likely would fail to meet the standard, the regulators said.
The state agency likely would press motorists to drive less often and use public transportation, Brown said. Such predictions are guesses.
"This is kind of a dangerous crystal ball to be looking into," Brown said.
The EPA's decision will follow a public comment period that ends Oct. 9.