Tag Archives: National Ambient Air Quality Standards

EPA Lowers the Ozone Standard to 70 PPB: Industry Isn’t Happy, But It Should Be

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, fortune-teller with a shining crystal ballbut 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

Two Wins in a Week for EPA on NAAQS: The DC Circuit Upholds EPA’s New SO2 Standard

On Wednesday, I discussed the DC Circuit’s decision affirming EPA’s revised NAAQS for NOx. Today, the DC Circuit upheld EPA’s revised SO2 standard. The tenor of today’s decision, written by David Sentelle, another Reagan appointee (the NOx decision was written by Douglas Ginsburg), is fairly similar to that in the NOx decision. Here’s the short version of the opinion:

EPA must establish NAAQS that protect public health with “an adequate margin of safety.” For that reason,… More

Not a Good Start for Challenges to EPA NAAQS Revisions: The District of Columbia Court of Appeals Affirms EPA’s New NOx NAAQS

Yesterday, in American Petroleum Institute v. EPA, the D.C. Circuit Court of Appeals affirmed EPA’s revisions to the National Ambient Air Quality Standard for NOx. The revisions adopted, for the first time, an hourly NAAQS for NOx, in addition to the annual standard.

API made a number of assertions that EPA had been arbitrary and capricious in its review of the scientific evidence concerning potential short-term impacts. The most important were EPA’s reliance,… More

EPA Proposes Revisions to the PM 2.5 NAAQS: How Much Will It Matter?

Last Thursday, in response to a court order, EPA finally proposed revisions to the national ambient air quality standard for PM2.5. The most significant part of the rule is EPA’s proposal to lower the primary annual standard from 15 ug/m3 to a range of from 12 ug/m3 to 13 ug/m3.

At a certain level, the proposal should not really be news and should not have a significant impact. After all,… More

More on a New Ozone NAAQS: EPA’s Clean Air Science Advisory Committee Endorses EPA’s Proposed Range

As we noted a few weeks ago, EPA has proposed lowering the NAAQS to a range of from 0.060 ppm – 0.070 ppm. Earlier this week, EPA’s Clean Air Science Advisory Committee, or CASAC, met and endorsed EPA’s proposed range. Some CASAC members did express concern about EPA’s proposed secondary seasonal standard, intended to protect crops and forests. However, overall, the CASAC seal of approval is pretty much the end of this argument.… More