Ozone levels in the Four Corners region—including New Mexico’s San Juan Basin—have been hovering just under the federal threshold of 70 parts per billion, according to data presented by Mark Sather, who works for the U.S. Environmental Protection Agency’s region six in air monitoring and grants, during the Four Corners Air Quality Task Force meeting on Tuesday. Region six includes New Mexico, Texas, Oklahoma, Arkansas and Louisiana.
The air quality task force is a multi-state, federal agencies and Tribal nations group that meets on an annual basis to share data and provide updates on initiatives to improve air quality. In the past, the meeting has alternated between Farmington and Durango, Colorado, but this year’s format was virtual due to the COVID-19 pandemic.
The ozone discussion comes just weeks after the EPA told a federal court that it will reassess a decision made in December 2020 to keep the National Ambient Air Quality Standards for ozone at 70 parts per billion. This could mean areas that are currently in attainment may fall out of attainment not because ozone levels in the area increase but because the standards become more stringent.
There have been discussions about changing the federal threshold to 65 parts per billion and the current standard of 70 parts per billion was implemented in 2015. Prior to 2015, the standards were 75 parts per billion.
Sather started by showing a map of air quality monitoring stations that look at ozone levels in region six. He said high concentrations can be seen in cities like Dallas and Fort Worth in Texas as well as in the Permian Basin in New Mexico. Sather pointed to an orange dot on the map in Albuquerque that represented one of the air monitoring stations. He said that the station has ozone levels over the federal threshold of 70 parts per billion.
“High ozone levels in New Mexico are driven by different sources in different parts of the state,” Michael Baca, with the New Mexico Environment Department’s Air Quality Bureau, said.
In some areas, oil and gas emissions are the main drivers of high ozone concentrations, while in other parts—like Albuquerque—vehicle transportation leads to high ozone levels.
While Sethar showed the entire EPA region six, the majority of his presentation focused on the Four Corners region, where all of the monitoring stations are below the federal threshold but some of them are pushing those levels.
If areas consistently fail to meet attainment of the federal ozone ambient air quality standards, consequences can include loss of federal funding for projects like highways. In determining attainment, the EPA looks at the fourth highest daily maximum ozone high concentrations averaged over three year time periods.
Sather presented preliminary data for the 2019 through 2021 time frame, which showed levels in Chaco Culture National Historical Park and Grand Canyon National Park at 68 parts per billion.
Ozone is formed when volatile organic compounds and oxides of nitrogen react in the presence of sunlight. It is generally connected to the combustion of fossil fuels and can be seen as smog.
New Mexico is in the process of creating rules that will address ozone precursors from oil and gas in areas that are currently pushing the federal threshold.
Baca said New Mexico is also working to educate the public about ozone.
“Our efforts to reduce air pollution could provide an improved buffer against any future violations that we may record,” he said.
The City of Albuquerque and Bernalillo County do not fall under NMED’s air quality jurisdiction and instead have their own entity that regulates air quality.
Baca said there is no guarantee that NMED’s actions will prevent areas from reaching nonattainment, but taking actions early will make it easier to address that if it does happen.
“We think it makes sense to take local steps to reduce air pollution on a voluntary basis before we have to make these a requirement and have to deal with the heavy handed and stringent requirements of the Clean Air Act for non-attainment areas,” he said.
