August 28, 2012

Interstate Air Transport Rule Vacated by the D.C. Circuit

Posted on August 28, 2012 by David Flannery

EPA was handed a setback in its efforts to establish aggressive controls on the energy industry in general, and the electric power industry in particular, when the D.C. Circuit issued its August 21, 2012 decision vacating the Cross-State Air Pollution Rule (CSAPR).  EME Homer City Generation LP v. EPA, Case. No. 11-1302. 

Significantly, the D.C. Circuit’s order not only vacated and remanded CSAPR, but also directed EPA to continue administering the previously-in-effect Clean Air Interstate Rule (CAIR) pending the promulgation of a valid replacement for CSAPR.  

In a 2 to 1 decision, the court ruled that CSAPR exceeded EPA’s authority in two areas:  

     a.    CSAPR impermissibly required upwind states to reduce more than their “significant contribution” to  downwind non-attainment; and
     b.    CSAPR deprived upwind states of the initial opportunity to implement any required emission reductions by immediately imposing a Federal Implementation Plan. 


Significantly, the opinion of the court sets forth a roadmap for the development of a CSAPR replacement rule. This is accomplished by the court’s establishing “several red lines that cabin EPA’s authority.” In many cases the court offers specific examples of the types of calculations that EPA would have to make in order to determine permissible emission reductions. These “red lines” and example calculations are summarized below:  

     1.    EPA cannot force an upwind state to reduce more than its own contribution to a downwind state minus what level EPA determines to be insignificant. 

Example:  If 3 units were set at the level of insignificance and an upwind state’s contribution to nonattainment in a downwind state is 30 units, then the most reduction that could be required of the upwind state would be 27.

     2.    EPA’s authority to force reductions on upwind states ends at the point where the downwind state achieves attainment. 

     3.    The extent to which an upwind state’s contribution is significant depends on the relative contribution to nonattainment of other upwind states.  The obligation to reduce emissions in the upwind states must be allocated “in proportion to the size of their contributions to downwind non-attainment.” 

Example 1:  Assume that the relevant national ambient air quality standard (NAAQS) is 100 units, that the ambient level of the at-issue pollutant in downwind state A is 150 units, and that state A is contributing 90 units to that overall concentration.  Assume also that three upwind states are each contributing 20 units to the total ambient concentration in downwind state A.  Under those circumstances, downwind state A is entitled to at most 50 units of relief — with the 3 upwind states each contributing 16 2/3 units.  

Example 2:  If the scenario in Example 1 were changed only to the extent that the upwind states contributed 10, 20 and 30 units respectively, the upwind states would be obligated to reduce their contributions by 8 1/3, 16 2/3 and 25 units, respectively.  

Example 3:  If the air quality measurement in Example 1 was 180 units and downwind state A contributed 120 of those units, with 3 upwind states contributing 20 units each, then downwind state A is entitled to at most 60 units of relief to be distributed proportionately among the upwind states.

     4.    EPA may consider costs, but only to further lower an individual state’s emission reduction obligation.  EPA may do this in a way that benefits some upwind states more than others.  The objective of reducing the control obligation of an upwind state would be to prevent exorbitant costs from being imposed on certain upwind states.  

     5.    EPA must ensure that the combined obligations of the various upwind states do not produce more control than necessary for the downwind state to achieve the NAAQS. 

Example:  If state A reduces 5,000 tons of NOx to achieve its largest downwind emission reduction obligation while state B reduces 2,000 tons for the same purpose, and if EPA modeling then shows that “all downwind non-attainment” would be resolved if the combined reduction of the two states were 10% lower, then EPA would be obligated to reduce the emissions reduction obligation of the upwind states by 10%.

The court’s ultimate holding on this aspect of the CSAPR decision is: 

States are obligated to prohibit only those “amounts” of pollution “which will . . . contribute significantly” to downwind attainment problems – and no more.  Because the Transport Rule exceeds those limits, and indeed does not really try to meet those requirements, it cannot stand.

Even as EPA considers its next steps in the wake of the decision, states and regulated sources will begin to focus on how to develop and implement a program to address interstate air quality that satisfies the new ground rules that have been established by the court.

Tags: EPAair pollutionCSAPRair quality

Air | Emissions | Environmental Protection Agency | State

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