/ Modified jul 30, 2019 4:22 p.m.

Ozone goes over EPA standard in Pima County for first time this year

The county has breached the federal levels 22 times since 2013. Maricopa County has exceeded the standard 20 times this year.

360 city of tucson Downtown Tucson seen from afar.
AZPM Staff

On July 25, the amount of ground-level ozone in Pima County exceeded federal pollution standards for the first time this year.

The Pima County Department of Environmental Quality reported monitors at Saguaro National Park East and Children's Memorial Park both exceeded standards set by the federal Environmental Protection Agency.

PDEQ cautions that exceeding the standard is not considered a violation.

"They allow a certain number of those exceedances before an area is considered violating the standard," said Beth Gorman, spokesperson, PDEQ.

Last week's level caught regulators by surprise.

"It could have been wind direction, it could have been that the wind just stopped and there was enough sunlight to cause that to happen, so we don't really know what happened at that point," said Gorman.

Ground-level ozone is caused by a combination of sunlight and emissions from vehicles, power plants, and industry. High levels of the pollutant can cause breathing problems.

Last year, Pima County exceeded the standards four times. In all, the county has breached the federal levels 22 times since 2013. In comparison, Maricopa County has exceeded the standard 20 times this year alone.

By posting comments, you agree to our
AZPM encourages comments, but comments that contain profanity, unrelated information, threats, libel, defamatory statements, obscenities, pornography or that violate the law are not allowed. Comments that promote commercial products or services are not allowed. Comments in violation of this policy will be removed. Continued posting of comments that violate this policy will result in the commenter being banned from the site.

By submitting your comments, you hereby give AZPM the right to post your comments and potentially use them in any other form of media operated by this institution.
Arizona Public Media broadcast stations are licensed to the Arizona Board of Regents. Arizona Public Media and AZPM are registered trademarks of the Arizona Board of Regents.
The University of Arizona