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

EnclosureEPA Response to Petition for Reconsidera tion from American Lung Association, Medical Advocates for Healthy Air, Na tural Resources Defense Council, and Sierra Club

The American Lung Association, Medical A dvocates 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 al so 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 denyi ng the Petition with respect to the remaining issue, i.e ., the transition period pos tponing 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 th e public from commenting on this element of the final PM2.5 Implementation Rule. The Petiti oners 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 notedthat 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 devel op 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 identi fies the filterable PM with an aerodynamic diameter less than 10 micrometers in di ameter, and method 201A separates out the filterable particulate matter that has an aerodynamic diameter of less than 2.5 micrometers in diameter. Method 202, origin ally promulgated in 1991, was developed tocharacterize condensable particulate matter and is used in conjunction with a filterable PM test method to quantify total fine partic ulate matter. This method includes a set of sampling procedures for collecting PM in water-filled impingers and a set of sample recovery procedures that ar e performed on the water followi ng 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 exis ting 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 additiona l 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 fo rm. The commenters argued that regulatory decision making and the identification of appr opriate control measures should be based on accurate measurements and a more prec ise test method. Thus, the commenters recommended that EPA should defer the requir ement that states include emissions limits for condensable particulate matter in their SI Ps 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 st ates should be required to include emission limits for condensable PM in the initialnonattainment 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 labo ratory evaluations by EPA and Environment Canada indicated that artifact could be significantly reduced with certain revisions to test me thod 202. EPA had indicated inthe 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 percen t. 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 es tablishing 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 tr ansition 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 prio r to January 2011. Thus, states retained the ability to implement emission limits for condens able PM emissions if they elected to use the existing test methods taking appropriatesteps 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 concl udes that the transition period was a logicaloutgrowth of the proposal and of the comme nts received thereon. For this reason, EPA denies the Petitioners’ requestfor reconsideration of this issue with respect to the procedural deficiency alleged by the Petitioners. EPA also be lieves that inclusion of the transition period was justified because the alle ged 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 th is issue with respect to the substantive deficiency alleged by the Petiti oners. 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 characterizi ng condensable PM for future regulatory purposes. This will also provide greater ce rtainty in air qualitymanagement 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 Implem entation 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 e xpeditiously [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 berequired 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 pe rmitting process for new or modified sources, states and sources are now required to a ddress 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.