UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

APR 2 5 2011 

THE ADMINISTRATOR 

Mr. Paul Cort 

Earthjustice 

426 17~ Street, Fifth Floor 

Oakland, California 946 12 

Dear Mr. Cort: 

I am responding to your June 25,2007, petition for reconsideration, filed on behalf of the 

American Lung Association, Medical Advocates for Healthy Air, the Natural Resources Defense 

Council and the Sierra Club. In the petition, you requested that the U. S. Environmental 

Protection Agency reconsider certain elements of the final "Clean Air Fine Particle 

Implementation Rule," published in the Federal Register on April 25,2007, and now codified at 

40 CRF section 5 1, subpart Z, the 2007 PM2.5 Implementation Rule. 

Your petition requested that the EPA reconsider four issues that appeared either in the 

regulatory provisions or in guidance in the preamble to the final rule: (i) the presumption that 

compliance with the Clean Air Interstate Rule would satisfy the requirement for reasonably 

available control technology for reducing sulh dioxide and nitrogen oxide from electric 

generating units located in nonattainment areas; (ii) certain revised criteria for analyzing the 

economic feasibility of reasonably available emission controls; (iii) the policy allowing states to 

include emissions reductions from outside the nonattainment area to meet reasonable further 

progress requirements; and (iv) the transition period for condensable particulate matter deferring 

the obligation for states to address condensable particulate matter in emission limits adopted into 

state implementation plans until January 20 1 1. 

By a letter dated May 14,20 10, the EPA has already granted your request for 

reconsideration on the issue of reasonable further progress. We have further reviewed your 

petition regarding the other three issues. The EPA' has decided to grant your request for 

reconsideration of the CAIR-RACT issue and the criteria for analyzing economic feasibility of 

controls issue. The EPA will publish a Federal Register notice that will announce the granting of 

your petition on these issues and take comment on proposed changes to the 2007 PM2.* 

Implementation Rule. After consideration of public comment, the EPA intends to finalize 

changes to the rule and the guidance, as appropriate. 

The EPA has decided to deny your request for reconsideration of the transition period for 

the condensable particulate matter issue. The enclosed document addresses the basis for this 

Internet Address (URL) htip:llwww.spa.gov 

Rwycl.dlRwyclrblo Prlnted with Vegetable 011 Based Inks on 100% Postconsumer, Process Chlorine Free Recycled Paper 
denial and explains more fblly the EPA's conclusions so you can better understand our final 

decision. 

In the meantime, the EPA appreciates your commitment to issues related to fine-particle 

pollution and your efforts to improve air quality. 

Sincerely, 

Lisa P. Jackson 

Enclosure 
EPA Response to Petition for Reconsideration from American Lung Association, 

Medical Advocates for Healthy Air, Natural Resources Defense Council, 

and Sierra Club 

The American Lung Association, Medical Advocates for Healthy Air, the Natural 

Resources Defense Council, and Sierra Club (the Petitioners) submitted a Petition for 

Reconsideration dated June 25, 2007 (the Petition), requesting that EPA reconsider four 

elements of the final “Clean Air Fine Particle Implementation Rule” (72 FR 20586; April 

25, 2007) now codified at 40 CFR part 51, subpart Z (the 2007 PM2.5 Implementation 

Rule). The 2007 PM2.5 Implementation Rule addressed the majority of the state 

implementation plan (SIP) requirements for nonattainment areas, as specified in Part D, 

subpart 1, of the Clean Air Act (CAA). EPA promulgated the final rule to implement the 

statutory requirements through specific regulatory provisions and also provided guidance 

concerning these requirements in the preamble. 

EPA has granted the Petition with respect to three of the four issues raised by 

Petitioners. In this response, EPA is denying the Petition with respect to the remaining 

issue, i.e., the transition period postponing the requirement for emissions limits for 

condensable PM from stationary sources until January 2011. 

 The Petitioners argued that the final 2007 PM2.5 Implementation Rule unlawfully 

and arbitrarily included a “transition period” allowing states to delay establishing limits 

or controls for condensable PM emissions until January 1, 2011. The Petitioners stated 

that the “transition period” and accompanying rationale did not appear in the proposed 

rule and that this improperly precluded the public from commenting on this element of 

the final PM2.5 Implementation Rule. The Petitioners also claimed that there could be no 

legal basis for such a transition period and that the effect of this transition period is to 

waive the CAA requirements for expeditious attainment and implementation of RACT 

unlawfully and arbitrarily. 

 In support of their arguments, the Petitioners referred to a number of statements in 

the proposal in which EPA emphasized the importance of addressing condensable 

particulate matter in air quality management activities. The Petitioners noted that EPA 

acknowledged that depending on the source category in question, condensable PM in 

some cases can be a significant portion of the total measured PM in a given 

nonattainment area. The Petitioners also noted that EPA recognized that having a better 

understanding of the mass and composition of condensable PM plus filterable PM from 

specific sources will enable states to develop more effective control strategies in the 

future. 

 In the proposal for the PM2.5 Implementation Rule, EPA described the principal 

source test methods for particulate matter. EPA method 5 is used to characterize total 

filterable particulate matter, method 201 identifies the filterable PM with an aerodynamic 

diameter less than 10 micrometers in diameter, and method 201A separates out the 

filterable particulate matter that has an aerodynamic diameter of less than 2.5 

micrometers in diameter. Method 202, originally promulgated in 1991, was developed to 
characterize condensable particulate matter and is used in conjunction with a filterable 

PM test method to quantify total fine particulate matter. This method includes a set of 

sampling procedures for collecting PM in water-filled impingers and a set of sample 

recovery procedures that are performed on the water following its collection. EPA also 

described the availability of conditional test method 40, a different, dilution-based test 

method for characterizing condensable PM2.5. 

 In response to the proposal, commenters objected to EPA’s approach to 

condensable PM on the grounds that the existing test methods were not reliable. 

Commenters argued that method 202 allowed for use of several different methodology 

options, some of which could result in the formation of “artifact” during the testing 

process. Artifact is additional condensable material formed in the glass bulbs used in the 

collection process (known as impingers) which would potentially overstate the amount of 

PM emitted by the sources in condensable form. The commenters argued that regulatory 

decision making and the identification of appropriate control measures should be based 

on accurate measurements and a more precise test method. Thus, the commenters 

recommended that EPA should defer the requirement that states include emissions limits 

for condensable particulate matter in their SIPs until the test methods could be modified 

to reduce alleged uncertainties. These comments concerning the accuracy of the test 

methods caused EPA to reevaluate whether states should be required to include emission 

limits for condensable PM in the initial nonattainment area SIPs for the 1997 PM2.5 

NAAQS, which states were required to submit by no later than April 2008. 

 In the preamble to the final PM2.5 Implementation Rule, EPA acknowledged the 

potential for artifact formation with method 202 and noted that laboratory evaluations by 

EPA and Environment Canada indicated that artifact could be significantly reduced with 

certain revisions to test method 202. EPA had indicated in the past that a one-hour 

nitrogen purge of the impinger water could remove SO2 before it could form sulfuric acid 

and reduce artifact formation by at least 90 percent. EPA also indicated its willingness to 

take steps to modify method 202 in order to provide greater certainty for the regulated 

community, for the states, and for EPA. The ultimate goal was to publish a refined test 

method that all parties could rely on for establishing emission limits for condensable PM 

in the future. Because EPA needed additional time to propose a revised test method and 

to complete a notice and comment process in order to finalize such a revised test method, 

EPA concluded that it should include a transition period allowing states to forgo 

addressing condensable emissions until January 2011 in the final 2007 PM2.5 

Implementation Rule. Significantly, EPA did not require states to forego regulation of 

condensables, if they elected to do so prior to January 2011. Thus, states retained the 

ability to implement emission limits for condensable PM emissions if they elected to use 

the existing test methods taking appropriate steps to assure accuracy. 

 In response to the Petition, EPA has evaluated whether its approach to 

condensable PM in the final 2007 PM2.5 Implementation Rule was correct. EPA 

believes that inclusion of the transition period was reasonable in light of comments 

received on the proposal that raised significant concerns with respect to the accuracy of 

the available test methods. Thus, EPA concludes that the transition period was a logical 
outgrowth of the proposal and of the comments received thereon. For this reason, EPA 

denies the Petitioners’ request for reconsideration of this issue with respect to the 

procedural deficiency alleged by the Petitioners. EPA also believes that inclusion of the 

transition period was justified because the alleged inaccuracies of the test methods could 

affect whether emissions limits imposed by states for condensable emissions were 

consistent with the requirements for reasonably available control measures and with the 

basic requirements for SIPs under section 110(a). For this reason, EPA denies the 

Petitioners’ request for reconsideration of this issue with respect to the substantive 

deficiency alleged by the Petitioners. EPA has concluded that allowing additional time to 

revise method 202 through notice and comment rulemaking was appropriate because it 

will allow the regulated community and state and federal regulators to have a more 

precise methodology to follow in characterizing condensable PM for future regulatory 

purposes. This will also provide greater certainty in air quality management and air 

permitting programs across the country. 

EPA finalized revisions to test method 202 and test method 201A on December 

21, 2010 (75 FR 80118). Accordingly, after January 1, 2011, states are required under 

the existing provision of the 2007 PM2.5 Implementation Rule to address condensable 

PM2.5 as well as filterable PM2.5 and to include emission limits in SIPs as necessary in 

order to attain the NAAQS expeditiously [see, 40 CFR 51.1002(c)]. Thus, for example, 

any area designated nonattainment for the 1997 PM2.5 NAAQS with an attainment date 

of 2014 or 2015 will need to conduct a mid-course review. In the event the area needs to 

submit additional measures to stay on course toward attainment, any new emission limits 

will need to address condensable PM. In addition, states will be required to address 

condensable PM in nonattainment SIPs due in December 2012 for areas designated 

nonattainment for the 2006 24-hour PM2.5 NAAQS. 

 It should also be noted that in the permitting process for new or modified sources, 

states and sources are now required to address condensable PM using the new test 

methods when establishing new or revised PM2.5 emission limits through the permitting 

process. These limits need to address the total of filterable and condensable PM.