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Critical Court Decision Concerning PM2.5 Emissions

Posted: February 18th, 2013

Author: All4 Staff 

In a suit brought by the Natural Resources Defense Council against the U.S. Environmental Protection Agency (U.S. EPA), the U.S. Court of Appeals for the District of Columbia Circuit (Court) on January 4, 2013 ruled that the U.S. EPA had improperly promulgated two rules implementing standards for fine particulate matter less than 2.5 micron in size (PM2.5).  This ruling creates a major issue for the U.S. EPA and state air pollution control agencies because it will likely undo 20 area redesignations in five states to attainment for PM2.5 that have already occurred and will definitely delay any pending redesignations.

This ruling determined that Congress required that State Implementation Plans (SIPs) for PM2.5 redesignation must meet the more stringent requirements of Part D, Subpart 4 in its 1990 amendments to the Clean Air Act (CAA).  The U.S. EPA had taken the position that the less burdensome requirements of Part D, Subpart 1 should be used in its implementation rules for PM2.5.  While it is not clear what additional measures must be met to comply with the full extent of this ruling, it is clear that additional sources of PM2.5 emissions, such as agriculture related sources with ammonia emissions (e.g. from concentrated animal feeding operations), may now have to be addressed for an acceptable SIP revision.  Subpart 4 as written in the CAA even requires that uncontrollable natural sources of fine particulate must be addressed in the SIPs.

There are many PM2.5 nonattainment areas of the nation that are currently monitoring attainment for PM2.5, and are about to or were just recently redesignated to attainment with the 1997 and/or 2006 PM2.5 national ambient air quality standards (NAAQS). For major PM2.5 emission sources in these areas with pending attainment designations or recent re-designations, the ability to permit any proposed facility modifications under the Prevention of Significant Deterioration (PSD) requirements applicable to attainment areas prior to the implementation of the new, more stringent annual PM2.5 NAAQS may be lost.  For PM2.5 the PSD attainment area requirements (e.g., BACT) are much less burdensome than the nonattainment new source review (NNSR) requirements for nonattainment areas (e.g., LAER and emission offsets).  The pending redesignations to attainment with the 1997 and/or 2006 PM2.5 NAAQS are compounded by the recently promulgated, and significantly lower, annual PM2.5 NAAQS, which could create more nonattainment areas.

Why is PM2.5 so significantly affected by this court decision relative to the other regulated pollutants? First, it only takes an emission increase in PM2.5 of 10 tons per year for a major source of PM2.5 to trigger NNSR permitting requirements.  Second PM2.5 emission offsets (known in Pennsylvania for example, as emission reduction credits (ERCs)) must be purchased or generated in order for the project to be permitted. Currently there is an extremely limited supply of PM2.5 emission offsets that can be purchased for use anywhere in the nation.  Where PM2.5 emission offsets are found, they have sold for more than $10,000 per ton, and sometimes well in excess of that figure.  While the Court may have been correct in their assessment of the CAA, their timing could not have been worse.  Many clean, economically stimulating, and environmentally sound projects will likely get caught up in this resetting of U.S. EPA’s implementation rules.

What can you do?  First, determine if your facility is in one of the PM2.5 redesignation areas or in an area likely to be nonattainment under the new PM2.5 NAAQS.  If so, the timing of your projects involving PM2.5 will be critical.  Once an area is designated as nonattainment, it is typically several years after the area is again monitoring attainment before it is redesignated for permitting purposes.  It is often a decade long process for a state control agency to obtain enough monitoring data, develop a Maintenance Plan and obtain U.S. EPA approval back to attainment.  If a facility has to seek PM2.5 ERCs under nonattainment NSR permitting, it could easily upset the viability of any new project in these unforgiving economic times.


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