EPA Will Reconsider the Ozone NAAQS — What Is An Adequate Margin of Safety, Anyway?

On Friday, EPA announced that it was reconsidering its 2020 decision to leave the National Ambient Air Quality Standards for ozone unchanged.  The reconsideration will be based on the existing record.  The notice does not identify any specific perceived flaws in the 2020 decision.  However, EPA stated that it:

will reconsider the decision to retain the ozone NAAQS in a manner that adheres to rigorous standards of scientific integrity.

The tone of the notice does seem to be full of portent.  I am sure that I am not the only reader who thinks that the likelihood that EPA will affirm the 2020 decision is approximately zero.

I support the reconsideration and there seems little doubt that the literal terms of the statute require a lower ozone NAAQS.  Otherwise, the phrase “adequate margin of safety” would have little meaning.

On the other hand, government regulation is about making hard choices – and the structure of the Clean Air Act leaves us without a mechanism to make those hard choices.  The NAAQS-setting process is supposed to be purely scientific.  And once the NAAQS are set, EPA is required through the SIP process to assure that they are attained.

I remain one of the few who believe in stringent regulation and the use of cost-benefit analysis in getting there.  I still think that the CAA is flawed and I don’t think I can improve on the discussion of those flaws that I provided at the time of EPA’s decision in 2020 to retain the 2015 ozone NAAQS.

Still whistling in the wind, I fear.

2 thoughts on “EPA Will Reconsider the Ozone NAAQS — What Is An Adequate Margin of Safety, Anyway?

  1. Your earlier post did address a major flaw, but now, here’s another few beyond what we knew in 1970.. The pollutant by pollutant approach has proven inadequate.For example, particle diameter isn’t enough to define the potential for harm without further discrimination of chemistry and shape. Every setting has a mix of exposure to single and multiple sources of both “Criteria” pollutants and “Hazardous Air Toxics “ sometimes subject to NESHAPs. Some are of local origin and others, like ozone and greenhouse gases, impact on regional or global scale. Some, notably methane, and CO2, were naively excluded. And, of course, State Implementation Plans don’t properly regulate regional and global problems. Cost Benefit consideration was ( justifiably) excluded in 1970 because of expectations that polluter money would buy deregulation.
    So, a better legislative framework might mandate enforceable regional multi-agency planning including the above and other factors. Congress is ready for that- NOT!

  2. Thanks as always for your thoughtful comments. I don’t know exactly where it all stands, but I’m pretty sure I’ve seen a number of items both from trade press and EPA’s press office about EPA’s efforts to start to regulate more on a multi-pollutant basis.

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