New York Among Cities That May Not Meet 2015 Ozone Standards

By Patrick Ambrosio

Sept. 21 — Various cities in the Northeast and mid-Atlantic U.S., including the New York metropolitan area, potentially won’t meet the 2015 ozone standards of 70 parts per billion, based on preliminary data from the summer of 2016.

The Environmental Protection Agency won’t formally designate areas that fail to attain the 2015 ozone standards until Oct. 1, 2017. However, Jeff Underhill of the New Hampshire Department of Environmental Services, offered a preview of potential nonattainment areas during a presentation shared at a Sept. 20 meeting of the Ozone Transport Commission.

Compliance with the ozone standards is based on a three-year average of the fourth highest eight-hour concentration measured each year. During his presentation, Underhill identified areas within the 13-state Ozone Transport Region that will potentially qualify as nonattainment areas based on data from 2014 and 2015, combined with preliminary air quality data from the summer of 2016.

The potential areas that won’t meet the 70 ppb ozone standards include Pittsburgh and an area that stretches along the I-95 corridor from Washington, D.C., up into Rhode Island, including the cities of Baltimore, Philadelphia and New York, according to Underhill’s presentation.

New York Above 80 Parts Per Billion

The New York metropolitan area, which has a three-year average above 80 ppb when preliminary 2016 data are included, is “in play” for a moderate nonattainment designation, Underhill said. Moderate nonattainment areas are given longer to meet national ambient air quality standards than marginal areas, which have less severe pollution issues but are subject to more extensive planning requirements.

If New York is designated a moderate nonattainment area, the state would have until October 2020 to submit a pollution control plan to bring the area into compliance by 2023.

Data from the summer of 2016 aren’t yet certified. Underhill said the preliminary air quality data show that 2016 “has been an interesting year” in the mid-Atlantic and the Northeast.

2016 Summer Consistent With 2015

While the summer of 2016 has been hotter than normal, likely driving electrical demand higher, the number of days with ozone concentrations exceeding the 70 ppb ozone standards actually declined in the region compared to 2015. There have been a total of 57 days in the Ozone Transport Region that saw an exceedance of the 70 ppb ozone standards during 2016, compared to 63 in 2015, according to Underhill’s presentation.

The preliminary 2016 results continue a “nice, downward trend” in the number of exceedance days within the region over the past 20 years, Underhill said. However, he cautioned that data from 2016 will replace data from 2013, a relatively low ozone year in the Northeast, for the purposes of determining compliance with federal ozone standards. In 2013, there were just 39 exceedance days in the region.

The three-year ozone averages, known as design values, could rise again after the 2017 ozone season ends in the Ozone Transport Region, according to Underhill. That’s because 2014 was another relatively low ozone year that will fall out of the three-year period used to calculate those design values, Underhill said.

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For More Information

Underhill’s presentation is available at

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