EPA Draft Policy Document Says Science Justifies Stricter Ozone Air Quality Standard

Turn to the nation's most objective and informative daily environmental news resource to learn how the United States and key players around the world are responding to the environmental...

By Jessica Coomes

Feb. 3 — Scientific evidence supports setting a more stringent ozone air quality standard, the Environmental Protection Agency said in a draft document Feb. 3.

The EPA is in the process of deciding whether to revise the current ozone national ambient air quality standard of 75 parts per billion, and a newly released draft policy assessment said the EPA would be justified in setting a standard between 60 ppb and 70 ppb.

“Compared to the current standard, a revised standard with a level from 70 to 60 ppb would be expected to increase public health protection against both short- and long-term [ozone] exposures, including for members of at-risk populations,” the EPA document, which was prepared by the agency's staff, said.

A stricter ozone standard would lead to new requirements for emissions controls on sources that emit nitrogen oxides and volatile organic compounds, which contribute to ozone formation, including industrial facilities, power plants and vehicles.

Five-Year Review

The Clean Air Act requires the EPA to review and consider revising air quality standards every five years. The EPA revised the ozone standard most recently in 2008 and missed its five-year deadline of 2013 to revise them. Advocacy groups are suing the EPA for missing the deadline and have asked a federal district court to order the agency to propose the rule by December 2014 and finalize it by October 2015.

A policy assessment analyzes scientific and technical information about ozone exposure and draws conclusions about policy implications. The EPA released the first draft of the policy assessment in 2012, and the newly released version is the second draft.

The policy assessment is a key document in the EPA's review process. The Clean Air Scientific Advisory Committee will discuss the assessment at a meeting March 25 to 27, and the EPA expects to finalize the policy assessment this summer.

An ozone standard between of 60 ppb and 70 ppb has been discussed for years. Before the EPA set the 75 ppb standard in 2008, the scientific advisory committee recommended a more stringent standard in the 60 ppb to 70 ppb range.

When President Barack Obama took office, the EPA announced it would reconsider the 75 ppb standard and issued a proposed rule with a standard between 60 ppb and 70 ppb. Obama eventually stopped that rulemaking process, and it later was disclosed that former EPA Administrator Lisa Jackson was prepared to finalize the standard at 70 ppb.

Final Decision Up to McCarthy

The latest draft said that although such a range could be justified, the final decision on the standard is up to EPA Administrator Gina McCarthy.

“In drawing these preliminary conclusions, staff additionally notes that the final decision on the adequacy of the current standard and consideration of potential alternative standards is largely a public welfare policy judgment to be made by the Administrator, drawing upon the scientific information as well as judgments about how to consider the range and magnitude of uncertainties that are inherent in the scientific evidence and technical analyses,” the assessment said.

Also Feb. 3, the EPA released the second drafts of documents called risk and exposure assessments, which evaluate the effects of ozone exposure. It said the agency has “estimated that exposures and risks remain after just meeting the existing standards and that in many cases, just meeting alternative standard levels results in reductions in those exposures and risks.”


To contact the reporter on this story: Jessica Coomes in Washington at jcoomes@bna.com

To contact the editor responsible for this story: Larry Pearl at lpearl@bna.com

The second draft policy assessment, released Feb. 3, is available at http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_2008_pa.html.

The second draft risk and exposure assessments, also released Feb. 3, are available at http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_2008_rea.html.

Request Environment & Energy Report