Ozone plan targets pollution in county

The Arkansas Department of Environmental Quality has put together a voluntary plan to reduce ozone pollution in Crittenden County.

The county is officially in attainment of the U.S. Environmental Protection Agency’s ozone standards. But the county, located in the major Memphis trucking corridor, has a history of noncompliance.

The department’s plan is open to public comment through the close of business Sept. 25.

The plan calls for reducing nitrogen oxide levels in the air, which are usually caused by on-road sources. Other emissions, like volatile organic compound emissions, come from sources that can’t be regulated.

Reductions would be achieved through more efficient fuels and infrastructure, improved industry equipment, carpooling and public transit, among other things.

Ground-level ozone, often referred to as smog, occurs naturally in the atmosphere but forms at ground level when car exhaust and industrial emissions react to high temperatures and sunlight.

Exposure to ground-level ozone can intensify allergies or respiratory problems for people who already have them. High levels of ozone can create respiratory problems for anyone who goes outside.

The EPA’s standard for ozone is 75 parts of ozone per billion parts of air, measured by taking the fourth-highest daily ozone level each year for three years and averaging that number. The standard will change to 70 late this year.

Officials have expected Crittenden County, which came in at 66 parts of ozone per billion parts of air in 2015, to achieve the new standard.