EPA’s Stealth Relaxation of Ozone Standard


For Immediate Release: Nov 01, 2018
Contact: Kirsten Stade (202) 265-7337

EPA’s Stealth Relaxation of Ozone Standard

Downwind States Must Endure More Ozone to Win Good Neighbor Protections

Washington, DC — The U.S. Environmental Protection Agency quietly issued guidance significantly increasing the allowable amount of ozone transport from an upwind state to a non-attaining downwind state, according to a document posted today by Public Employees for Environmental Responsibility (PEER). This will make it harder for downwind states to invoke the “good neighbor” protections under the Clean Air Act and meet national ambient air quality standards.

In an August 31, 2018 memo to all Regional Air Division Directors, Peter Tsirigotis, Director of EPA’s Office of Air Quality Planning and Standards, raised the amount of “upwind contribution” from 0.70 ppb (parts-per-billion) to 1 ppb, a more than 40% increase. He justified the change by writing:

“Although the 1 ppb threshold captures somewhat less upwind contribution …[it] still generally captures a substantial amount of transported contribution from upwind states to downwind receptors.”

The guidance contains tables estimating that, on average, the relaxed thresholds will capture 86% of what would be captured by the tighter threshold, but in the worst-case scenario, it would capture only 37.9%.

“With a flick of the pen, this EPA guidance condemns hundreds of unlucky downwinders to early deaths every year,” stated PEER Science Policy Director Kyla Bennett, a scientist and attorney formerly with EPA, noting that prolonged exposure to ozone is linked to premature death, cardiovascular impairments, and respiratory diseases. “When it comes to our lungs, EPA should do better than ‘good enough for government work.’”

This guidance means that downwind states will have to accept more ozone from their upwind neighbors before EPA will step in and invoke the Clean Air Act “good neighbors” safeguards. On the other hand, a state utilizing the new relaxed thresholds may be challenged in court. Nor is there a guarantee that EPA will help defend the action as the guidance contains a caveat that relying on the new ozone thresholds “does not ensure that the EPA will approve a SIP [state implementation plan] revision.”

In 2015, EPA tightened the overall National Ambient Air Quality Standards for ozone, which is a secondary air pollutant created by chemical reactions between nitrous oxide (NOX) and volatile organic compounds (VOCs). Since Trump’s inauguration, EPA has been chipping away at ozone protections, such as a behind-the-scenes move this spring to allow industry to exceed current ambient air standards over rivers, mountains, and other remote areas.

“Under the Trump administration, our prospects for breathable air are being subjected to a death of a thousand cuts, and this is just the latest one,” added Bennett. “Instead of promoting good neighbors, EPA is running down the whole neighborhood.”


Read the EPA memo

See American Lung Association ozone warnings

View outdoor ambient air rollback

Phone: 202-265-7337

962 Wayne Avenue, Suite 610
Silver Spring, MD 20910-4453

Copyright 2001–2024 Public Employees for
Environmental Responsibility

PEER is a 501(c)(3) organization
EIN: 93-1102740