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  • Preliminary data indicate violation of EPA ozone standard in County

    Aug 03, 2018 | Read More News
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    Preliminary data from the Pima County Department of Environmental Quality indicates that the air quality monitor at Saguaro National Park East violated the U.S. Environmental Protection Agency’s (EPA) ground-level ozone standard yesterday. The data will need to be validated through an extensive QA/QC process and sent to EPA before it becomes official. The formula to determine a violation of the EPA health standards allows for several exceedances of the standard before a violation occurs. The Saguaro National Park has exceeded the standard several times, including four times so far in 2018.
    In 2015, after reviewing numerous scientific and health studies, the EPA changed the ground-level ozone standard to be more protective of public health. This is the first time any of the monitors in Pima County has violated the ozone standard. In April of 2018, Pima County was designated as in attainment of the ozone standard by the EPA and that designation will remain in effect until EPA takes further action.
    “The standards were created to protect public health and we are concerned that ozone levels have reached the point of a violation,” said Ursula Nelson, Director of Pima County Department of Environmental Quality. “Once the data is validated and sent to EPA, there will be a period of time before any decisions are made regarding next steps for our region. In the meantime, each one of us can take actions on a daily basis that will reduce the emissions that contribute to the formation of ozone, including driving our vehicles less and reducing engine idling,” Nelson said.
    More information about ground-level ozone and actions that can be taken to improve air quality is available at PDEQ’s website.