From: Lydia Wegman/RTP/USEPA/US

To: nfrey@omb.eop.gov Cc: James Hemby/RTP/USEPA/US@EPA, Michael Ling/RTP/USEPA/US@EPA, Peter

Keller/RTP/USEPA/US@EPA, Lewis Weinstock/RTP/USEPA/US@EPA, Tim Hanley/RTP/USEPA/US@EPA, Joseph

- J Dougherty/DC/USEPA/US@EPA, Anna Wood/RTP/USEPA/US@EPA, Richard Wayland/RTP/USEPA/US@EPA, Pad mini Singh/DC/USEPA/US@EPA, Sara Schneeberg/DC/USEPA/US@EPA, Beth Hassett

Sipple/RTP/USEPA/US@EPA, Scott Jenkins/RTP/USEPA/US@EPA, martin.karen@epa.gov Date: 06/08/2012 08:50 AM Subject: Responses to monitoring and implementation comments

Nathan,

Attac hed are our responses to the monitoring and implementation comments we've received from the interagency group. We hope you can distribute them prior to our 1:30 meeting today. Please let me know if you have any questions. Thanks.General Comments

Questions 1

- 3 are answered collectively below

.
1) Attainment and Monitoring EPA proposes to eliminate spatial averaging and "population

- oriented" monitor placement, while mandating a near

- road component to monitoring plans. Some

c ommenters believe that these three provisions are internally inconsistent. Spatial averaging is a statistical means of expressing the 'ambient' aspect of "National Ambient Air Quality Standards." Averaging over the regulated area creates the regulatory consistency for the regional jurisdictions that is key to the regionally

controlled implementation of the NAAQS. EPA cites the possibility of disparate health effects on disadvantaged populations as the reason for eliminating averaging.

However, EPA also proposes t o eliminate "population

- oriented" monitor placement, since EPA says that the concept of a monitor being population

- oriented is incompatible with the 'ambient' nature of the NAAQS. In this provision, EPA dismisses linking NAAQS attainment to health effects as inconsistent with statute, even though the touchstone of the NAAQS standards is in fact public health.

2) Some commenters believe that EPA's reasoning for a near

- road component to monitoring plans is inconsistent with its reasoning above. Near

- road PM l evels are

not necessarily representative of actual risk to susceptible populations through exposure to PM. Nor is the placement of near

- road monitors calculated to be a better proxy for health effects than "population

- oriented" monitors. The elimination of spatial averaging and "population

- oriented" monitors and the establishment of near

road monitors can only have the effect of making NAAQS attainment more difficult.

3) Some commenters also note that the proposed PM standards and their impacts appear to be based on existing monitoring systems, such that the addition of near

road monitors can increase the costs by putting additional areas into nonattainment
without associated health benefits.

To clarify, we are not proposing to eliminate the establishment or regulatory use of population

- oriented monitors. This is the very type of monitor that the agency agrees are essential to assessing compliance with any primary PM (or other criteria pollutant) standard

-- monitoring sites that are representative
of concen trations to which populations are potentially exposed. In fact, every currently operating PM 2.5 site in the country and any sites being proposed in this rule are population

- oriented by the existing definition and are therefore comparable to the PM standards. So, we are confident the change we areproposing (i.e., revocation of the requirement that P M 2.5 monitoring sites be

“population

- oriented” for comparison to the NAAQS) will have effectively minimal if any practical impact.

One of EPA’s goals with this proposed change is to provide consistency and predictability in the interpretation of monitori ng regulations among all the NAAQS pollutants and eliminate the specific areas of confusion that have occurred in the past when EPA and the states review PM 2.5 monitoring data. EPA certainly does not agree that a monitor being population

- oriented is incomp atible with the ambient nature of the NAAQS and if such a statement
was made help us to identify it so that we can correct or clarify the statement. We agree the corner stone of the NAAQS standards is in fact public health.

Regarding the proposed near

- road PM 2.5 monitoring, EPA is proposing that all

near - road monitors be sited in locations that are representative of other highly traffic road segments in a given CBSA. And since near

- road environments occur throughout a metropolitan area, these monitors are therefore representative of concentrations to which the populations in these environments are exposed. As stated in the preamble, EPA also believes the

near - road PM 2.5 monitors will be useful for many monitoring objectives beyond comparison with the NAAQS

. N ear - road environments are complicated air quality locations that the Agency, in order to protect public health, is obligated to better understand. For example, the proposed requirement s for the PM 2.5 near - road monitors include co - locati on at near
road stations with NO 2 and CO monitors ( stations which are soon to be deployed per previous final rules ) . Collectively, these measurements will be invaluable to understanding an important type of location that is ubiquitous throughout the country and in which a significant percentage of the American population lives and works.

With respect to your commen ts on spatial averaging, as part of the 2006 review, EPA tightened the criteria for use of spatial averaging to provide increased protection for vulnerable populations exposed to PM 2.5 . This change was based in part on an analysis of the potential for disp roportionate impacts on potentially susceptible populations, which found that the highest
concentrations in an area tend to be measured at monitors located in areas where the surrounding population is more likely to have lower education and income levels, and higher percentages of minority populations (71 FR 61166/2, October 17, 2006; US EPA, 2005, section 5.3.6.1). In this review, as discussed in section III.B.3 of the preamble, based on additional health data,the Integrated Science Assessment has identi fied persons from lower

socioeconomic strata as a susceptible population (US EPA, 2009a, section 8.1.7; US EPA, 2011a, section 2.2.1). And as explained in the preamble, the proposed elimination provision is based on an analysis that indicates the existing constraints on spatial averaging, as modified in 2006, may be inadequate to avoid substantially greater exposures in some areas, potentially resulting in disproportionate impacts on susceptible populations (Schmidt 2011a, Analysis A). In reviewing how s patial averaging is applied now, we note that no CBSA in the country has requested the use of spatial averaging since the criteria were
revised in 2006.

While we may not fully understand your comment that the proposed near road r equirements may increase co sts with no associated health benefit
, we do not agree that this is the case for two fundamental reasons. First, EPA has worked to design an implementation approach for the proposed near

- road monitoring that is as cost effective as is feasible. Since we have proposed to
focus of the near

- road network in large CBSA’s (52 stations nationally representing CBSA’s over 1M in population), EPA believes that the PM 2.5 monitor requirement can be met by relocating existing sites rather than adding new sites

. Fu rther, because near

- road monitoring stations are already required to be operational for CO and NO 2 , cost savings and operational
efficiencies will be realized by locating PM2.5 instruments at the same site. Secondly, we simply do not know if the near

- road monitors will result in any additional areas being designated nonattainment and will not until three years of valid data are collected and certified and these data work their way through the designation process. However, as explained in the preamble,
the re are lots of good reasons to collect these data. We do believe that the availability of these data will support many monitoring objectives including comparison to the NAAQS that would lead to health benefits.4) Some commenters note that any difficulties in achieving attainment will likely

translate into difficulties in PSD permitting. The elimination of spatial averaging, along with the inclusion of near

- road monitors, is likely to make it more difficult to obtain permits. These commenters note that wh ere EPA changes its interpretation about 'exclusion of some receptors' in PSD analyses, it does account for these changes and suggest that EPA clearly identify how these changes may or may not affect permitting decisions.

As we noted in the previous versio n of the NPRM, we do not expect any significant adverse PSD permitting impacts as a result of the proposed monitoring regulation clarifications. In order to resolve some confusion caused by the previous draft of the NPRM, we would recommend replacing the text beginning at the first full paragraph on page 402. The draft revised language in the PSD section addressing this would read as follows:

“ In addition to the NAAQS revisions themselves, for which proposed and other possible implementation actions are described further below, t he EPA is proposing certain clarifications to the existing monitoring regulations codified at 40 CFR 58.30 (Special co nsiderations for data comparisons to the NAAQS). These proposed clarifications are presented in detail in section VIII.B.2 of this preamble. The monitoring regulations provide a basis for determining whether specific monitoring sites are comparable to spec ific NAAQS. By extension, EPA has used the principles of making these determinations for monitoring sites to also guide permitting authorities in assessing the comparability of specific receptor locations involved in PSD air quality analyses. Receptors are used in PSD modeling analyses to predict potential air quality impacts in the vicinity of the proposed new or modified facility and in some cases also at more distant Class I areas. The EPA will continue to use these principles in guiding PSD modeling an alysis design. Accordingly, if the proposed PM NAAQS revisions and monitoring regulation clarifications described previously are finalized, permitting agencies will continue to have the flexibility to qualify or disqualify specific receptor locations used in PSD air quality analyses consistent with
th ose provisions.”

We would then pick up at the last full paragraph on page 403 prior to subsection a.

23) Some commenters suggest that EPA should request comment whether it should move forward with the primary and secondary standards on the same timeline and on whether the designations must move forward in tandem. This is especiallyimportant given how differ ent the visibility measure is from previous efforts and

given that major rules affecting PM (GHG mobile sources and Boiler MACT) are not included in the baseline analysis and the significant work required in some states to comply with CSAPR

- better

- than

- BAR T or state

- specific consent decrees.

We understand the comment but note that this request is already made. The current designation section of the preamble describes the basic designations timeframe under the Act, in which designations commonly would be fi nalized by EPA within two years, but that EPA can take an additional year in the event there is "insufficient information" to complete the process in two years. We do point out that there could be good technical reasons (e.g. same sources contributing to both problems) to conduct designations for the primary and secondary PM2.5 NAAQS concurrently for areas that have adequate data. This approach could also result in certain implementation efficiencies for states down the road, in that implementation plans for both primary and secondary standards could be adopted and submitted on the same state rule adoption schedule. The section states that EPA remains flexible with regard to the designation schedule. Nevertheless, the section also concludes with the

stat ement that "EPA invites preliminary comment on all aspects of the designation process at this time, which the Agency will consider in developing that guidance." We believe this section provides adequate opportunity for interested parties to provide commen ts on the designations process for the secondary standards.

24) Some commenters recommend that EPA should signal maximum flexibility in its enforcement of CAA timelines. For example, EPA has discretion to provide up to 2 1

- year extensions on secondary standar ds. Given the nature of this new requirement and the modeling difficulties that EPA acknowledges, EPA should indicate willingness to grant these extensions.

EPA supports having language in the implementation portion of the preamble that identifies where flexibility can be provided on CAA timelines. As noted below, we refer to several places where flexibility could be provided, in the context of taking preliminary comment on implementation approaches that we would more specifically address in the upcomin g implementation rules/guidance. To further emphasize the point, we could add a general statement at the end of the first paragraph of the introduction, to the effect of: "This discussion also highlights relevant CAA provisions that provide potential fle xibility with regard to meeting implementation timelines under the Act." Also, with respect to the specific example, we can add a sentence to the sections on implementing the primary and secondary standards which references the possibility of an area obta ining a 1

- year extension to itsattainment date if the air quality data for the last of the 3 years evaluated to

determine attainment is below the level of the standard; and the possibility of an area obtaining a second 1

- year extension to its attainment d ate if the
average of the air quality data for the last of the 3 years evaluated to determine attainment AND the first extension year is below the level of the standard.

Please note that the following sections in the draft preamble already refer to certain provisions providing flexibility to states:

- The Designations section states: "Section 107(d)(1)(B)(i) further provides, “Upon promulgation or revision of a NAAQS, the Administrator shall promulgate the designations of all areas (or portions the reof) ... as expeditiously as practicable, but in no case later than 2 years from the date of promulgation. Such period may be extended for up to one year in the event the Administrator has insufficient information to promulgate the designations .”

- The S ection 110(a)(2) Infrastructure SIP section states: " Section 110(b) of the CAA provides that the EPA may extend the deadline for the “infrastructure” SIP submission for a new secondary standard by up to 18 months beyond the initial 3 years . The EPA curren tly believes it would be more efficient for states and the EPA if each affected state submits a single section 110 infrastructure SIP that addresses both the revised primary annual PM2.5 NAAQS and the new secondary PM2.5 visibility index NAAQS at the

same time (i.e., within 3 years of promulgation of any revisions to the NAAQS for PM), because the EPA does not at present discern any need for there to be any substantive difference in the infrastructure SIPs for the two standards. However, the EPA also recogn izes that states may prefer the flexibility to submit the secondary NAAQS attainment SIP at a later date. The EPA solicits comment on this timing aspect."

- The section on Implementing the Primary PM2.5 NAAQS states:

"Under section 172, states are requ ired to submit SIPs within 3 years of the effective date of area designations by EPA. These plans need to show how the nonattainment area will attain the primary PM2.5 standards “as expeditiously as practicable,” but presumptively no later than within 5 ye ars from the effective date of designations. However, in certain cases, the EPA can approve attainment dates up to 10 years from the effective date of designations, as appropriate, considering the severity of the air quality concentrations in the area, and the availability and feasibility of emission control measures ."

"Under the approach outlined in the implementation rule for the 1997 PM2.5 NAAQS, for an area that can demonstrate it will attain the standard within the presumptive 5

- year period from desig nation, its attainment demonstration will be considered to meet the RFP requirement. The EPA believes it isappropriate to apply this same approach for the revised annual primary

PM2.5 standard."

- The section on Implementing the Secondary PM2.5 NAAQS sta tes:

"For secondary NAAQS, however, section 172(a)(2)(B) defines the attainment date for an area designated nonattainment as “the date by which attainment can be achieved as expeditiously as practicable” but with no maximum limitation. Thus, it is possi ble for EPA to approve a part D SIP that provides for attainment of the secondary standards by a date more than 10 years after the date of designation with an appropriate demonstration."

- The sections on Transportation Conformity and General Conformity e ach state that these programs do not apply in a nonattainment area until one year after the designations are effective, allowing for an appropriate transition between old and new standards.

Questions 25 and 26 are answered collectively below:

25) Under 40 CFR 52.21(o) and (p), visibility analyses are routinely conducted as part of the PSD process. Commenters express concern regarding the potential creation of a different set of analytical requirements for the PM2.5 visibility index that may

crea te "competing" techniques for visibility assessment between the proposed PM2.5 visibility index and Class I procedures which could undermine existing processes and requirements used to protect visibility in Class I wilderness areas.

26) Some commenters s uggest that the Agency remove the language describing a paucity of supporting speciation data. This language could be construed such that the current methods used for visibility assessment for Class I analyses are not adequate, and that EPA is instead pro posing to use a simple surrogacy technique. The implications of this could weaken the technical credibility of the tools used for Class I visibility assessments under 40 CFR 52.21(p) or the Class II visibility assessments under the Additional Impact Analy sis ( 40 CFR 52.21(o)) of the PSD rule. Moreover, at 70 FR 39121 EPA identified the CALPUFF system as "the best currently available tool for analyzing the visibility effects of individual sources." These commenters requested clarification upon why the me thods that have been routinely used for visibility assessment under the PSD program are not deemed applicable to the proposed PM2.5 visibility index.

We agree that the current preamble language the PM2.5 surrogacy approach for the proposed secondary vis ibility standard should be modified to clarify the rationale for the policy as well as explain that this surrogacy policy in no way impacts the assessments of visibility for PSD purposes under 40 CFR52.21(o) and (p), calls into question the technical adeq uacy of these

assessments or creates a different and 'competing' set of analytical requirements fore the Class I procedures. Please see attached edits intended to address these concerns on page 409 through 413 of the preamble. We welcome any additional ed its for interagency reviewers.