2020 ozone season wraps up

Ground-level ozone forms when emissions from sources such as vehicles, industry and power plants react with heat and sunlight. Thankfully, the 2020 ozone season (March 1–Oct. 31) featured a temperate summer with a well-timed series of rainy days, which limited air stagnation keeping ground-level ozone in check. Additionally, the COVID-19 pandemic may have influenced ground-level ozone levels during early summer when Kansas City metro residents were less likely to drive to work.

The single exceedance of the federal health-based ground-level ozone standard occurred during the height of summer on July 7. To determine whether the Kansas City region met the seasonal standard set by the U.S. Environmental Protection Agency, validated monitor readings for 2020 will be averaged with monitor readings from 2019 and 2018 to create a design value. Based on preliminary data, this should be the seventh consecutive year in which the region has met the ozone standard.

Although July 7 was the only day when monitors showed an exceedance of the federal health-based standard for ground level-ozone pollution, the Mid-America Regional Council (MARC) twice encouraged residents to limit outdoor activity due to high levels of particulate matter pollution. Controlled burns in the Kansas Flint Hills on April 8 and dust from the Sahara Desert on June 28 moved through the Greater Kansas City region leading to increased levels of particulate matter. On both days, MARC did not issue an Ozone Alert because ozone levels were in the healthy range but encouraged residents to stay indoors or limit outdoor activity.

Despite a very good 2020 ozone season, it is important to stay on guard and continue to take steps to reduce air pollution. Throughout each ozone season, MARC will continue to issue daily SkyCasts for ground-level ozone. The SkyCast uses a color-coded scale corresponding with the EPA’s Air Quality Index to quickly and easily determine risk level and recommended personal actions: green for healthy air, yellow for moderate ozone levels, and orange and red for Ozone Alerts. Whenever we expect orange or higher ozone levels, residents are actively alerted and encouraged to take actions to protect their health and help reduce emissions. Solutions may include mowing your lawn before 10 a.m. or after 7 p.m. and biking or walking instead of driving.

The Kansas City region continues to employ voluntary strategies to reduce ozone-forming and greenhouse gas emissions, as outlined in the region’s award-winning Clean Air Action Plan (CAAP). Our participation in the Ozone Advance program also helps guide local efforts to reduce ozone pollution.