Yesterday, EPA formalized its decision to leave the ozone 
NAAQS unchanged, at 70 ppb. I don’t think that this decision is in the same category of egregiousness as EPA’s recent decision not to reduce the PM2.5 NAAQS. After all, only one decision can be the single worst environmental policy of an entire administration.
I’m not that close to the science on the ozone NAAQS,… More
On Tuesday, the District of Columbia Court of Appeals vacated EPA’s “Close-Out Rule,” which basically concluded that upwind states contributing to exceedances of the National Ambient Air Quality Standard for ozone in downwind states did not have to undertake any additional actions to reduce their contribution to downwind state ozone concentrations. 
The decision was inevitable following last month’s decision in Wisconsin v. EPA,… More
Last Friday, the D.C. Circuit Court of Appeals ruled that EPA violated the Clean Air Act in failing to impose deadlines on upwind states violating the CAA’s Good Neighbor provisions. 
The Court concluded that, where downwind states face significant consequences in not meeting statutory deadlines to attain National Ambient Air Quality Standards, but don’t control their own fate because upwind states are contributing significantly to the downwind states’ nonattainment,… More
The D.C. Circuit today largely upheld EPA’s 2015 revisions to the National Ambient Air Quality Standard for ozone. I’m not much of a prognosticator, but I pretty much called this one years ago. The Court was never going to require EPA to consider costs in setting the NAAQS – not a surprise, given that the Supreme Court concluded in Whitman v.… More
Last week, the Court of Appeals for the District of Columbia struck down EPA’s rule implementing the 2008 ozone standards. My primary take-away? The structure of the Clean Air Act is so dense and so complicated that it gives me a headache, and I do like to think I’m something of an expert. Those of us who believe in government regulation need to be honest and admit that there’s a reason why some people become Libertarians. … More
An article published Friday in Science reports that the Antarctic ozone hole 
is healing. As the article notes, there was some previous evidence about global improvement in stratospheric ozone levels, but this is the first to document improvement in Antarctica.
Aside from the fact that good news is always welcome, it’s also a useful reminder that environmental regulation can work. In the developed world,… More
Earlier this week, the “Public Health and Environmental Petitioners” challenging EPA’s decision not to reduce the ozone 
standard below 0.070 ppm filed their “Non-Binding Statement of Issues.” My crystal ball still tells me that the most likely outcome is that the Court of Appeals upholds EPA’s 0.070 ppm standard.
I do think that the Public Health and Environmental Petitioners have a better case than Murray Energy (which filed its Statement of Issues late last year). … More
On Thursday, EPA finally released its final rule revising the ozone NAAQS to 70 ppb. I do not spend much time peering into a crystal ball, 
but I will go out on a limb and say that the industry challenges to the rule will fail. Just ain’t gonna happen.
The environmental group challenges pose a more interesting question. There’s a fair bit of evidence of health impacts below 70 ppb,… More
Earlier this week, the 9th Circuit Court of Appeals granted part of a petition challenging EPA’s approval of California’s SIP for ozone and PM 2.5 in the San Joaquin Valley. 
While the trade press has been focusing on the partial reversal, I think that EPA won much more than it lost.
What did it lose? California’s plans for complying with the ozone and PM 2.5 NAAQS relied in part on emissions reductions to be attained as a result of California’s authority under the CAA to impose more stringent mobile source emissions standards than are applicable nationally. … More
Yesterday, EPA finally proposed a revised ambient air quality standard for ozone – except that the agency is still hedging its bets. The Clean Air Science Advisory Committee had previously supported a revised ozone NAAQS of 0.060 to 0.070 ppm. EPA has narrowed the range slightly, proposing a revised NAAQS of from 0.065 to 0.070 ppm, but still has not yet picked a number.… More
On Friday, EPA released its “Policy Assessment for the Review of the Ozone 
National Ambient Air Quality Standards.” EPA staff concluded:
that it is appropriate in this review to consider a revised primary O3 standard level within the range of 70 ppb to 60 ppb. A standard set within this range would result in important improvements in public protection, compared to the current standard,… More
As we have noted previously, EPA has had difficulty in promulgating a revised National Ambient Air Quality Standard for ozone. Whenever the revised NAAQS is issued – and EPA is under court deadline to propose a draft by December 1, 2014 and a issue a final by October 1, 2015 – the actual standard that EPA is likely to issue is coming into focus.
Late last week,… More
On Monday, EPA released its second external review draft of an updated Policy Assessment on the national ambient air quality standard for ozone. It also released updated draft risk and exposure assessments. To no one’s surprise, the new drafts confirm support for lowering the ozone NAAQS from 75 ppb to a range of 60 ppb to 70 ppb.
Why is this not a surprise? … More
As the Supreme Court gets ready to consider the validity of EPA’s Cross-State Air Pollution Rule, some of the Northeastern and Mid-Atlantic states are taking another tack to address at least part of the air pollution transport issue. They have petitioned EPA under § 176A of the Clean Air Act to add Illinois, Indiana, Kentucky, Michigan, North Carolina, Ohio, Tennessee, Virginia, and West Virginia to the Ozone Transport Region established under § 184 of the CAA.… More
On Tuesday, in Mississippi v. EPA, the Court of Appeals for the D.C. Circuit affirmed EPA’s 2008 NAAQS for ozone of 0.075 ppm. However, it remanded EPA’s decision to set the secondary NAAQS, for public welfare, at the same 0.075 ppm level. With respect to the primary standard, the Court gave short shrift to industry and red-state challenges that the standard was too stringent. This is not surprising,… More