The summer of 2017 was the cleanest ground-level ozone season in Virginia in at least 20 years, according to the Department of Environmental Quality.
“We have made tremendous improvements in Virginia’s air quality in the past two decades,” DEQ Director David K. Paylor said. “Though we still have work to do to ensure that our air remains clean, the progress we have seen so far is a great benefit to all Virginians.”
For years now, the trend for air quality in Virginia has been one of steady improvement. Pollutants such as ozone, nitrogen oxides, sulfur dioxide, carbon monoxide and particles have shown consistent declines and emissions of these pollutants in Virginia have decreased by almost 60 percent in the past 20 years.
Remarkably this has happened in spite of an ever increasing demand for electricity and many more vehicles on Virginia’s highways.
Twenty years ago, the ozone health standard was 120 parts per billion, and many urban areas in the Commonwealth failed to meet it. Now, only four days this summer had ozone levels that exceeded the current, more stringent ozone standard of 70 ppb as of the end of September.
These high ozone readings were limited to Arlington and Fairfax counties, with four exceedances, and Henrico and Giles counties, each with one. All other areas of Virginia had no high ozone days in 2017. This year is even better than the second-cleanest year of 2013, when five high ozone days were recorded.
In addition, Virginia is seeking redesignation for the Northern Virginia area from the U.S. Environmental Protection Agency under the 2008 ozone standard (75 ppb). EPA will soon formally announce that the region has attained the 2008 standard, clearing the way for the redesignation that DEQ is seeking.
The 2017 ozone season compares with years in the 1990s when multiple ozone exceedances occurred on a single day, and in some cases there were dozens of days statewide that experienced high ozone. The average number of high ozone days in the 1990s was 86, including a high of 108 in 1993 and 1998.
More information about air quality is on the DEQ website at www.deq.virginia.gov