National Ambient Air Quality Standards

In October 2015, EPA reduced the level of the National Ambient Air Quality Standards (“NAAQS”) for ozone from 75 parts per billion (“ppb”) to 70 ppb. What is happening concerning implementation of those NAAQS?

Although litigation over EPA’s decision to lower the ozone NAAQS remains in abeyance as the Trump Administration continues to consider whether the Agency should reconsider the rule or some part of it, the 2015 standard itself has not been stayed. Thus, the Clean Air Act requires that implementation of the standard proceed. One key step in implementation is promulgation by EPA of a list of areas where the standard is violated, including areas that contribute to standard violations in nearby areas. EPA’s identification of these “nonattainment” areas is a trigger for many of the Act’s control requirements. Continue Reading What’s Up with Air Quality Standards for Ozone?

On April 11, 2017, the United States Court of Appeals for the District of Columbia Circuit canceled oral argument, which had been scheduled for April 19, in several consolidated cases challenging EPA’s 2015 revision of National Ambient Air Quality Standards (NAAQS) for ozone. The court took this action, and ordered that the case be held in abeyance, in response to an EPA motion asking that oral argument be continued, to give the appropriate Trump administration officials adequate time to review those standards. EPA’s motion indicated that the new administration is deciding whether to reconsider them.

What is the regulatory significance of the court’s action?

Continue Reading National Ambient Air Quality Standards for Ozone: With Litigation in Abeyance, What Now?