Confusion and Anxiety: The Very Latest on the Re-Revised Ozone Standard

摘要

In March 2008, the EPA finalized new 8-hour primary and secondary ozonestandards. These standards, equal to 0.075 ppm, represented a significant tightening over theprevious 0.08 ppm 8-hour standard. However, less than a year and a half later, EPAannounced that it was going to reconsider the recently revised standards. EPA was now of anopinion that the scientific evidence as to the effects of ozone on children and other at-riskmembers of the population warranted a reconsideration of the primary standard and thatimpacts on vegetation and forested ecosystems warranted reconsideration of the secondarystandard. In January 2010, EPA promulgated a proposal that would set the primary standardbetween 0.060 and 0.070 ppm and would establish a cumulative secondary standard within arange of 7-15 ppm-hours. Originally scheduled for final promulgation by August 31, 2010, EPAhas since announced that issuance of the re-revised standards will not be until the end of July2011. Dependent upon where the ozone standards are set, regulatory agencies may bedealing with a large increase in the number of counties that are designated as not inattainment of one or both of the revised standards. Designing and implementing StateImplementation Plans that will demonstrate attainment with a primary standard that could,especially at the lower end of the proposed range (0.060 ppm), approach backgroundconcentrations will pose a very significant challenge for regulatory agencies and the industriesthat they regulate.