Tag Archives: PM

There have been numerous studies that support a decrease in the current PM2.5 annual standard of 12 ug/m3.  EPA has nonetheless proposed to retain the current standard on the basis that there is too much uncertainty regarding whether those studies provide a basis for concluding that PM2.5 concentrations below the standard cause increased mortality.  As I have previously noted, the statutory provision requires that NAAQS be set with an “adequate margin of safety.”  That would seem to require EPA to resolve such uncertainty in favor of a more stringent standard.… More

Last month, I noted that EPA’s Office of Air Quality Planning and Standards had released a draft reassessment of the particulate matter NAAQS.  In a bold moment of speculation, I indicated that it would be difficult for EPA to avoid lowering the PM2.5 NAAQS to between 8.0 and 10.0 micrograms/cubic meter.  Following issuance of the draft, and in order to ensure that EPA does not ignore the emerging scientific consensus,… More

EPA’s Office of Air Quality Planning and Standards has released a draft of its reassessment of the adequacy of the current national ambient air quality standard for particulate matter.  Here’s the primary takeaway concerning PM2.5:

The risk assessment estimates that the current primary PM2.5 standards could allow a substantial number of PM2.5-associated deaths in the U.S.

When taken together, we reach the preliminary conclusion that the available scientific evidence,… More

Last week, EPA posted its draft Integrated Science Assessment for Particulate Matter.  It’s the foundational document for EPA’s periodic review of its National Ambient Air Quality Standard for PM.  The current standard for PM2.5, promulgated in 2012, is 12 ug/m3.

Section 109 of the Clean Air Act requires the Administrator to set the NAAQS “requisite to protect the public health” with “an adequate margin of safety.”

The new ISA states that:

Evidence from U.S.… More

As regular readers know, the tension between guidance and regulation is one of my favorite topics.  My view is that, in general, guidance is too often used simply to avoid notice and comment rulemaking and that, once issued, it is treated by those implementing it in the agency street-level bureaucracy as though it were a rule.  Nonetheless, guidance is sometimes appropriate.  The recent decision in Sierra Club v.… More

Given how easy it can be to get discouraged about progress in addressing climate change, I think it’s helpful periodically to remember how much progress the U.S. has made in fighting air pollution.  It thus seemed useful to note this story about current conditions in New Delhi, where PM levels are so high that one million (!) students are being kept home from school.

It’s also helpful to remember the tension inherent in the climate change fight.  … More

Although citizen groups have suffered some defeats in Clean Air Act cases in the NSR/PSD context recently, a decision last week in a different kind of CAA case is a reminder of just how powerful a weapon citizen suits can be, and just how difficult they can be to defend, even when the operator appears to have a good working relationship with the regulator.  In NRDC v.… More

There has been a lot of scholarly discussion in recent years about the importance of putting a price on natural resources.  The pricing issue has been particularly in the limelight in connection with the drought in the western United States.  Indeed, it seems fairly self-evident that, if we give away a scarce resource, people will consume too much of it.

I suppose, then, that we should not be surprised that we have already been one-upped on this issue by the Chinese. … More

If anyone had any doubts about the significance of the conventional pollutant regulations that EPA would be rolling out, even in the absence of a full cap-and-trade program for GHG, Wednesday’s release of EPA’s revised power plant MACT proposal should go a long way towards eliminating those doubts. As most readers know, the rule replaces the Bush-era MACT rule that would have created a trading program.

The rule poses a problem for critics of EPA. While arguments can be made about the feasibility of some of the standards and the cost to comply,… More