### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 1

- Environmental Protection Agency (EPA) : Proposed Rule

Fine Particulate Matter (PM 2.5 ) National Ambient Air Quality Standards (NAAQS) :

State Implementation Plan (SIP) Requirements

RIN 2060

- A Q48

General Comments

1. Wildfire and wildland fire

.

a. Commenter s recomm end including additional context and background in the preamble and rule language about prescribed fire (planned ignitions) and wildfire (unplanned ignitions). Specifically, that not including prescribed fire and wildfire may unintentionally set a precede nce that limits the options for managing wildland fire, limits the role of wildland fire in restoring and maintaining resilient landscapes, preclude options for effective management of carbon, and inadvertently violate the direction set forth in Executive Order (EO) 13653.

Response : We understand the commenter’s interest in providing more context for

fire related issues . The text below was adapted from language to be included in

the final 2008 ozone SIP requirements rule, and we recommend adding it as a footnote on page 1 6

, following table 1, which describes national emissions by

sector.

“ It should be noted that the “miscellaneous” sector has the highest level of estimated PM2.5 emissions primarily d ue to emissions from wildfire. Wildfire emissions can significan tly contribute to periodic high PM 2.5 levels. Besides their effect on air quality, wildfires pose a direct threat to public safety

– a threat that can be mitigated through management of wildland vegetation. Attempts to suppress wildfires have

resulted in u nintended consequences, including increased risks to both humans and ecosystems. The use of wildland prescribed fire can influence the occurrence of catastrophic wildfires which may help manage the contribution of wildfires to PM 2.5 concentrations. Additio nally prescribed fires can have benefits to those plant and animal species that depend upon natural fires for propagation, habitat restoration, and reproduction, as well as myriad ecosystem functions (e.g., carbon sequestration). The

EPA understands the im portance of prescribed fire which mimics a natural process necessary to manage and maintain fire

- adapted ecosystems and climate change adaptation, while reducing risk of uncontrolled emissions from catastrophic wildfires, and is committed to working with f ederal land managers, tribes, and states to effectively manage wildland fire use to reduce the impact of wildfire related

emissions

. ”

2. Precursor policy options.

a. Commenter recommends considering hybrid approaches to addressing regulation

of PM 2.5 precursors in attainment plans and nonattainment new source review (NNSR). Specifically, one hybrid approach could have Option 2A as a screening

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 2

- mechanism for whether a particular PM 2.5 precu r sor is important or a significant

contributor to nonattainment in the area, and if so, Option 3 could then be utilized to demonstrate that control measures for all types of sources of a particular precursor are not needed for expeditious attainment of that area.

Response : The precursor policy options in the proposed rule start from EPA’s interpretation of the statute that all precursors are to be addressed in attainment planning and NNSR unless the state provides an adequate demonstration showing that a particular precursor is not significant. Note that the three dra ft options are presented broadly in order to elicit a wide range of comments that can be considered for developing the final rule.

The suggested hybrid option proposes a combination of options 2A and 3. Option 2A would allow the state to provide a techni cal demonstration showing that all emissions ( i.e

. , from area, mobile, and stationary sources in the area) of a particular precursor collectively do not provide a significant contribution to PM 2.5 levels that exceed the standard in the area

. Option 3 stat es that an attainment planning (i.e., RACM and RACT) analysis demonstrating that control measures for all types of sources of a particular precursor are not needed for expeditious attainment also would be deemed to meet the section 189(e) technical

demonst ration requirement, meaning that the state would not need to regulate

emissions of the particular precursor from major stationary sources under the NNSR permitting program or impose other control requirements for major stationary sources

. Note that under o ption 2A, if an adequate demonstration is made, then the state would not need to evaluate control measures for attainment planning purposes or for NNSR for that particular precursor. Thus, Option 2A

would achieve a similar result to what the commenter seem s to be advocating for by suggesting a hybrid of Options 2A and 3. For this reaso n, we do not see the need to present a specific option 2A

- option 3 hybrid , but we have modified the last paragraph of the pr ecursor policy section on page 80 to acknowledge t he possibility of considering a hybrid approach :

“The EPA also seeks comment on whether only one of these approaches should be included in the final rule, or whether it would be appropriate to include multiple approaches ( e.g. , both Options 1 and 2) or a hybrid of two approaches by which a state could demonstrate that a particular precursor would not need to be addressed in the attainment plan or permitting program for a specific area.”

3. De minimis determination.

a. Reviewer r ecommend s providing an alternat ive for “safe harbor” type provisions

for de minimis determinations. The alternative would state that if the contribution is below a certain percentage (e.g., 3 percent) it would be considered de minimis and an amount greater than that percentage would re quire additional justification

to determine that the contribution is de minimis

.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 3

- Response : The concept of de minimis is already presented in the proposal in two ways: with regard to emissions of a particular precursor, and with regard to

emissions from a particular sourc e category; and with each proposed approach, there is a “no threshold” option and an option in which de minimis could be considered to be up to 3% of the relevant standard

.

On page 13 1 , EPA requests comment on several questions, which ind icate the complexity of this issue:

“ The EPA is requesting comment on the appropriateness of including de minimis threshold option s for exempting certain source categories from consideration for

re a sonable control measure determinations, and seeks input on the following questions: If a de minimis threshold is included, what is the appropriate definition for source categories? What are the appropriate thresholds for impacts on ambient

PM 2.5 concentrations that would adequately reflect presumptive de minimi s concentrations from a given source category comparable to those recommended for purpose of the PM 10 NAAQS? Should the de minimis source category
thresholds be a percentage of the relevant NAAQS ( i.e

. , similar to what was

recommended for PM 10 but set at a level that is more appropriate for the level and form of the relevant NAAQS) ? The EPA requests that commenters submit any relevant data or analyses to support their comments with respect to these issues

. Furthermore, the EPA notes that even in the event t he agency finalizes this rulemaking with a de minimis source category policy of any kind, states are obligated under the CAA to demonstrate how their PM 2.5 nonattainment area will attain the standard as expeditiously as practicable. Accordingly, a state co uld not elect to treat source categories as de minimis if doing so would prevent the state from being able to demonstrate attainment for the area by the statutory attainment

date. ”

The presentation of these two approaches to de minimis determinations , and two options per approach, already introduces a fair degree of complexity to this concept. The policy space that is “defined” by the options is broad enough to include consideration of other options suggested by commenters. We believe the addition of a

thi rd option to each of the two approaches to de minimis in the proposal will add too much complexity, and for this reason we decline to change the proposal as suggested by the reviewer.

4. Base year.

a. Reviewer r ecommend s considering additional years as the base year for attainment plans and determinations ; including providing additional discussion as to why the Air Emissions Reporting Rule (AERR) should not be used as a base

year.

b. Response : As described on page 100 , there is great flexibility in the inventory year. The inventory year must be one of the 3 years used for designations or

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 4

- another technical ly appropriate year. The specific circumstances for which another year could be appropriate are provided. Since the AERR is collected on a triennial schedule, an AERR year would always be available as an option under this approach, provided that an AERR year is appropriate considering other factors, such as meteorology, that should be considered for selecting a year in the

event an attainment demonstration is ne eded. For these reasons, we do not believe additional changes are needed to this section.

5. North American Industry Classification System (NAICS)

.

a. Reviewer r ecommend s providing additional discussion on the differe nces in 2, 4, and 6 digit codes and why 4 d igit codes are the most appropriate.

Response : We added the discussion below to page 12 9 . It was taken from the Census Bureau webpage at: http://www.census.gov/eos/www/naics/faqs/faqs.html#q5

“NAICS is a 2

- through 6

- digit hierarchical classification sy stem, offering five levels of detail. Each digit in the code is part of a series of progressively narrower categories, and the more digits in the code signify greater classification detail. The first two digits designate the economic sector, the third digi t designates the subsector, the fourth digit designates the industry group, the fifth digit designates the NAICS industry, and the sixth digit designates the national industry. The 5

- digit NAICS code is the level at which there is comparability in code and definitions for most of the NAICS sectors across the three countries participating in NAICS (the United States, Canada, and Mexico). The 6

- digit level allows for the United States, Canada, and Mexico each to have country

- specific detail. A complete and va lid NAICS code contains six digits.”

We also revised the following sentence later on the same page:

“ For this reason, the EPA proposes and seeks comment on a requirement that a state would need to define any source category for which a NAICS code exis ts at
the four

- digit industry group level

. The EPA believes that relying on the four

- digit industry group level to define “source category” for this purpose would provide an appropriate degree of distinction between industrial processes while not making th e source category definition overly broad. The EPA also seeks comment on two other alternative approaches for defining source category for this purpose

, at the six

- digit level, and the two

- digit level. ”

6. Use of previous r easonably a vailable c ontrol m easure s (RACM) and r easonably

a vailable c ontrol t echnology (RACT)

.

a. Reviewer r ecommend s evaluating a “recent threshold” (e.g., within 3 years of when this RACM/RACT is performed) that would allow either no u pdate s or a less extensive update to RACM and RACT

.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 5

- Res ponse : We do not believe the statute authorizes EPA to establish a presumption that

any RACM/ RACT determination made in the past 3 years automatically is adequate for this new SIP. The state would still need to present its case that additional control is not technologically and/or economically feasible and t hat the recent determination represents
RACM/RACT for the new SIP, and we would expect that in many cases, a determination made in the past 3 years would be adequate. To address this comment, we r ecomm end adding the underlined text to pa ge 133 :

“ The EPA recognizes that for some sources located in a Moderate PM 2.5 nonattainment area, a state may have previously conducted RACM and RACT analyses to address emissions for other statutory purposes. Some of t he RACM and RACT determinations could be relatively recent, while other determinations may be 15 years old or older. The EPA proposes that a state may not simply rely on a previous RACM or RACT determination for a particular source or source category when developing the attainment plan for a PM 2.5 NAAQS, but rather that the state must consider all existing and potential new measures together as part of a comprehensive RACM and RACT analysis. In this way, the state’s new RACM and RACT analysis will represent the most thorough, up

- to

date review of control measures for its PM 2.5 nonattainment area

. For example, the state would still need to provide a RACT analysis for a source that has installed new emission controls recently (e.g. within the last three years) , but the state’s determination may consider that recen t installation when determing whether addition al control is economically and technologically feasible

. ”

7. Technical feasibility determination. (140 )

a. Commenter recommends clarifying that for agricultural sources that mitigation measures that may be technically feasible for one agricultural source may not be technically feasible for a similar type of agricultural operation.

Response : We believe that the existing text provides sufficient flexibility to al low a state to present information describing why one emission reduction approach would be technically feasible at one specific source while it would not be technically feasible at another source. We decline to add specific language regarding agricultural operations because this rule is intended to provide broad guidance that applies to a wide range of states and source types, providing as much flexibility as possible under the statute for air agencies to determine an appropriate control strategy for their PM2.5 nonattainment areas but without providing specific guidance for each potential type of source category that could be addressed in a SIP. For this reason, we have not included source

- category specific statements in the preamble, and believe we should maintain this approach.

8. Economic feasibility determination

.

a. Reviewer recommends clarifying whether sources with similar technological characteristics owned by different sized entities are considered “similar sources” with respect to economic feasibility o r would a state be allowed to justify

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 6

- rejection based on the size of entities applying such technology. EPA states that a state may not reject technologically feasible measures as economically infeasible if similar sources have implemented the technology, absent adequate justification. Therefore, while a state may consider engineering criteria to evaluate technological feasibility, small entities could be required to install economically infeasible technologies solely because a similar source owned by a l arger facility has install the technology.

Response : States have flexibility to determine appropriate RACM, including RACT, based on a full evaluation of the “ feasibility ” aspect of “ reasonably

available. ” Proven technologies or measures may not be economically feasible or cost effective in every potential application. The preamble specifically allows a state the discretion to decline to require the control if it is able to provide an adequate justification for the differing treatment. In addition, we have added the underlined text to the sentence on page 141 to help clarify what is meant by the

term “similar source”:

“ Furthermore, the EPA proposes that a state may not reject a technologically feasible control measure or technology as being economically infeasible if such a measure or technology has been implemented at other similar sources (i.e., at sources that would be included in the same source category in the emission inventory data collection process) , unless the state provides a n adequate justification that cl early explains the specific circumstances of the source or sources in the nonattainment area that make such a measure or technology economically infeasible in that particular area. ”

We also note that later in this section (page 142), there is language ena bling a state to provide information to demonstrate why an entity should not be considered to be able to afford a particular control measure used on similar sources. The language reads as follows:

“ In addition, if a state contends that a source

- specific c ontrol

- level should not be established because the source(s) cannot afford the control measure or technology that is demonstrated to be economically feasible for other sources in its source category, the EPA proposes that the state must support the claim w ith information regarding the impact of imposing the identified control measure or technology on the following financial indicators, to the extent applicable:

1. F ixed and variable production costs ($/unit)

2. P roduct supply and demand elasticity

3. P roduc t prices (cost absorption vs. cost pass

- through)

4. E xpected costs incurred by competitors

5. C ompany profits

6. E mployment costs

7. O ther costs ( e.g. , for RACM implemented by public sector entities).

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 7

- The EPA seeks comment on the factors described above f or states to consider when determining whether a control technology or measure is economically feasible. ”

A r eviewer has recommended that two additional factors be added to this list: 8. Impact on jobs and 9. Cumulative impacts to the source not consider ed above (e.g., delays in maintenance or other potential safety

- related actions).

This list of factors is taken from long

- standing guidance (the 1992 General Preamble) that is applicable to implementation of more than just the PM NAAQS.

A reviewer has r ecommended that two additional factors be added to this list: 8. Impact on jobs and 9. Cumulative impacts to the source not considered above (e.g., delays in maintenance or other potential safety

- related actions). We think the guidance has proven sufficie ntly broad and has provided adequate flexibility to states to be able to present reasoning to demonstrate why certain facilities are not able to afford control technology used on similar sources. C hanging the longstanding guidance ri sks introducing confusion to states in their attainment planning process with little potential gain in return.

b. Reviewer r ecommend s evaluating whether “safe harbor” type provisions for economic feasibility with respect to cost effectiveness are appropriate

.

Response : The proposed rule intentionally does not include a safe harbor provision or bright line with respect to what cost effectiveness level would be considered appropriate or inappropriate under all circumstances. The reason for this is that every n onattainment area is different, and some areas have more serious air quality problems than others. In order to attain the standard and protect public health sufficiently in these areas, control measures may need to be adopted in the state that have higher per ton levels than control measures needed to attain for areas with less serious air quality problems.

9. Attainment demonstration. (17 3 )

a. Reviewer r ecommend s providing benefits and costs of each of the proposed

alternatives for the attainment demonstration

. For example, discuss the relative level of risk of just using FRM and/or FEM monitoring data.

Response : (We assume this comment addresses the options for addressing unmonitored areas in the attainment demonstration.) The occu rrence of potential high

PM 2.5 concentrations in unmonitored areas is by definition unknown and cannot be evaluated without completing a case

- by

- case analysis for each nonattainment area. It is therefore not possible at this time to calculate the benefits and costs of each of the

pr oposed attainment demonstration alternatives.

That said, we can make some qualitative observations. For example: Option 1, which requires attainment to be shown only at monitoring locations, would be expected to

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 8

- be the le a s t costly option to implement

. Option 2, which would require the state to

conduct an unmonitored area analysis as part of all attainment demonstrations and require the state to eliminate potential violations in unmonitored areas through

enforceable emissions reductions in the SIP

, could potentially lead to additional

control costs

. However, any additional control costs would be accompanied by

concurrent additional health benefits

. The magnitude of these potential costs and benefits would vary on a case

- by

- case basis.

Since we are unable to estimate the potential costs and benefits of the various options

in a meaningful way, we do not believe a dditional preamble language would help provide useful information to the reader to help decide between the options. We

therefore are not making any changes to the preamble language.

10. Credits for outside of nonattainment area for reasonable fur ther progress (RFP).

a. Reviewer r ecommend s providing additional discussion why EPA thought it was appropriate to allow up to 200 kilometers (km) away from the nonattainment area

for RFP in the 2007 PM 2.5 Implementation Rule and does not believe that it is st ill appropriate.

Response : We plan to add clarifying text to page 19 9 to explain t he issue more clearly and fully, and to make it consistent with EPA ’ s approach to RFP and

treatment of sources outside the nonattainment area in the upcoming final 2008

ozone SI P requirements rule

.

b. (196) Reviewer recommends considering credits outside of the nonattainment

area for RFP b ecause the EPA is requiring the use of outside the nonattainment

area actions as “additional reasonable measures” to have a nonattainment area achieve attainment as expeditiously as possible and is allowing the use of outside the nonattainment area actions (but still within the state) as cont ingency measures

within the SIP . For example, if the nonattainment area needs to decr ease emission s by 6 percent over a 6 year period, for a linear a RFP, the nonattainment area would need to decrease by 1 percent a year. However, if because of the

“additional reasonable measures

, ” the nonattainment area can demonstrate

attainment within 4 years, the nonattainment area would need to decrease emissions by 1.5 p ercent a year. But because a state cannot credit outside the

nonattainment area for RFP, the state may not be able to meet their RFP requirements.

Response : If a state implements additional reasonable measures , and those

measures include emission reduction strategies on sources located outside the

nonattainment area

, and these would advance the attainment date from 6 years to 4 years, then the reduction obligation for the first fou r years for the sources within

the nonattainment area (i.e., the reductions that are the basis for establishing RFP) would likely be the same or reduced, as compared to a scenario where the attainment strategy relied strictly on reductions from sources wi thin the

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 9

- nonattainment area. The most important issue in this hypothetical scenario is that

the additional reasonable measures would lead to attainment a full two years sooner. By attaining the standard in the area that much sooner, significant health

bene fits would be realized in the nonattainment area. With air quality improving due to the additional reasonable measures, as well as from reductions from sources within the nonattainment area, it is possible that sources in the

nonattainment area would not n eed to reduce emissions to the same degree. In any case, however, it would seem likely that EPA would have the flexibility under the implementation rule for PM2.5 ( in contrast to the ozone implementation program, which has certain statutory percent reducti on requirements for emissions within the nonattainment area) to find that the reductions that are anticipated from

sources in the nonattainment area would be considered to provide for “generally linear progress” toward attainment.

c. (14 5 ) Reviewer recomme nds providing additional basis and clarification for the term “additional reasonable measures,” including whether this term has been defined or used in other criteria pollutants of the Clean Air Act. If the term has not been previously used, the reviewer recommends explaining why PM 2.5 is different than the other criteria pollutants that this requirement should be added.

Response : Subpart 4 requires attainment for Moderate areas by the end of the 6 th
year after designation, yet requires RACM to be submit ted by the end of the 4 th
year. (If designations take effect early in the calendar year, as is the case for the recent designations under the 2012 standard, then the time period from the effective date of designation to the attainment date could be close t o seven years.) The term “additional reasonable measures” has not been defined previously for

PM10 or for ozone , but the term is being introduced in the draft PM2.5 implementation rule to make it clear that if there are other potential control

measures oth er than RACM/RACT that are feasible and cost

- effective

, could be implemented between the end of the 4 th year and the attainment date, and are needed for the area to attain by the attainment date, then the state is required to adopt them. One reason that t he ozone and PM10 programs have not included the “additional reasonable measures” term in past implementation guidance may be because both programs have had specific requirements for EPA development of control measures guidance documents for specific key s ource categories

. For ozone, there are more than 3 0 control techniques guidance (CTG) and alternative control technology (ACT) documents that have been developed for reducing VOC emissions. For PM10, section 190 of the CAA included requirements for EPA to develop guidance by 1992 on controlling key PM10 sources of concern (that were prevalent in certain areas in the late 1980’s) such as wood smoke, fugitive dust, and prescribed fire. There is no additional obligation for EPA to develop control measure guida nce for specific PM2.5 source categories. However, the ” additional

reasonable measures ” provision will require states to adopt and implement control

measures that cannot come on

- line until years 5 or 6 after designation if such

emission reductions are need ed to attain the standard expeditiously.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 10

- 11. Electronic submissions for RFP

.

a. Reviewer r ecommend s strengthening the language in the use of electronic communication and an electronic reporting system.

Response : We have modified the text on page 20 9 to addre ss this comment:

“ The EPA stated in the Addendum that the milestone report must be submitted from the Governor or Governor’s designee to the Regional Administrator of the respective EPA Regional Office serving the submitting state, and that the EPA will n otify the state of its determination (regarding whether or not the state’s report is adequate) by sending a letter to the appropriate Governor or Governor’s designee. The EPA believes that given the improvements in electronic communication in the interveni ng years since the Addendum was issued, it would be appropriate to provide an electronic reporting capability or system for such milestone reports that simplifies the process and reduces resource burden on all sides. The EPA is investigating how to institu te such a system

, seeks comment on how electronic reporting could facilitate a state’s submittal of the required milestone

report , how it could accommodate the various narrative and data

- dependent components that the EPA is proposing be part of such a subm ittal , and what system features would be recommended by commenters. ”

12. Extensions for attainment.

a. (2 21 , 23 5 ) Reviewer r ecommend s providing additional explanation of the

difference between the attainment determinations in the previous PM 2.5 Implementation Rule and this proposed rule and examples of specific cases where

an extension would be needed and granted

.

Response : We assume this comment refers to section J, attainment date

extensions. We believe the preamble provides sufficient clarity on attainment date extensions for Moderate and Serious areas, so we do not recommend making any changes to the document. However, below we provide additional explanation to

address the reviewer’s concerns:

This section of the preamble describes the situation for an a rea that has reached its attainment date, and the area’s 3

- year design value is above the level of the standard, but the value for the third year is below the level of the standard. Under these circumstances, a Moderate area would be eligible to receive a one

- year attainment date extension. If the air quality concentration during the next year after receiving the extension is also below the level of the standard, the area can

receive a second one

- year extension. Note that these one

- year extensions are on ly provided for Moderate areas, and the statut e requires an evaluat ion of current air quality before an extension may be granted

.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 11

- After an area is reclassified as Serious, it must then provide a new attainment demonstration showing that it will attain the standard within ten years of initial designation. If it identifies available control measures and conducts an assessment to determine whether it can attain by the end of year 10, and it

determines that it cannot attain by the end of year 10, then the plan must also include an analysis to show by what year it can attain. Under these circumstances, the CAA allows the state to submit a request for a Serious area attainment date extension of up to an additional five years. Note that in contrast to the Moderate

area one

- year extension provision (which requires an evaluati on of current air quality data), the Serious area attainment date extension is requested in advance based on the state’s attainment demonstration analysis of what would be its most expeditious future attainment date. The statute does not have a one

- year attainment date extension provision for Serious areas.

b. Reviewer r ecommend s providing additional cl arification on the difference in plan submittals between a Moderate nonattainment area plan and Serious nonattainment area plan for granting an ex tension

.

Response : Please see response above.

13. Attainment date for Serious nonattainment areas.

a. Reviewer r ecommend s clarifying that “10 years after designation” is as of

“nonattainment” and should n ot be considered as of designation as of Serious

nonattainment.

Response : We provide here a clarification between the term “designation” and “classification.” The proposal has used the term “designation” or “initial designation” to mean the process that occurs within 2

- 3 years after the NAAQS is revised to designate areas as attainment or nonattainment. The statute requires all areas that have been initially designated as nonattainment for PM2.5 to be

“classified” as Moderate. When a Moderate area fails to attain the standard by the

end of the 6 th year after it was initially designated as nonattainment, the area is then “reclassified” as Serious. (It is not “designated” as Serious.)

To address this comment, we have slightly modifie d the relevant sente nce on page 30 4 :

“ For example, for a Serious nonattainment area, a future case scenario for the year 2025 (10 years after the initial nonattainment designation) is needed to examine whether the measures identified by the state would result in attainment. ”

14. Emission inventory.

a. Commenter recommends developing a mechanism to allow for the use of emissions estimating methodologies (EEM) for animal production operations

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 12

- under the National Air Emissions Monitory Study (NAEMS) when they become

available.

Respon se : The current draft proposed rule already promotes the use of the best available data, which would include EEMs based on the NAEMS data if and when such methodologies become available for estimating emissions from animal production operations. As descr ibed on page 9 8 , CAA section 172(c)(3) requires a “comprehensive, accurate, and current inventory of actual emissions,” and the preamble further stresses that the “specific attainment plan requirements for the PM2.5 NAAQS set forth in section 189(a) and a ssociated modeling requirements make an accurate and up

- to

- date emissions inventory a critical element of any viable attainment plan.” The current draft also continues on page 9 8 to say that “States should use the best available, current emissions inventor y information for attainment plan development, because high quality emissions inventory data are essential for the development of an effective control strategy.” Thus, it should be evident (without explicitly providing the suggested details in this rule) t hat new approaches such as the future EEMs using NAEMS data would be an option when such methodologies become available.

Furthermore, there are countless other emissions categories and countless associated emissions estimating approaches that could be use d for estimating the emissions from these sources. To ensure that the approaches remain flexible and

up

- to

- date, the emissions inventory guidance has traditionally been the place to address such specific recommendation methodologies, and this is the approa ch that we recommend in this case as well. It is unnecessary and infeasible to address all of the current and possible future approaches for every source category in this rulemaking notice, nor would we do so for a single source category.

15. Emission invento ry decrease for Serious nonattainment areas that have failed to

achieve attainment.

a. Reviewer r ecommend s providing clarification on EPA’s determination process for determining if a Serious nonattainment area that fails to attain has decreased emissions by 5 percent each year.

Response : We have added the following paragraph on page 34 9 to clarify that quantitative milestone reporting would be used to track compliance with the 5% annual emission reduction requirement. We acknowledge that annual tracking of

e missions is highly resource

- intensive and therefore difficult for states.

“ The section 189(d) requirement to reduce emissions by 5% per year is in effect a fixed level of reasonable further progress to be achieved annually. Accordingly, just as quantitat ive milestones are used to track progress with RFP requirements, it is proposed that the state would be required to submit quantitative milestone reports to describe the area’s progress in meeting the 5% annual emission reduction requirement

under section 189(d). See section VII.G for more details. ”

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 13

- b. R eviewer r ecommend s providing additional clarification of the “most recent inventory” in relation to Clean Air Act (CAA) section 189(d). If a state is required to calculate the inventory for the nonattainment area each year to determine if the nonattainment area has decreased emissions by 5 percent, does the 5 percent change to that year’s inventory or is it 5 percent of t he initial inventory calculated?

Response : To provide additional clarification , we have r evised the text on page 344

as follows:

‘ The statute requires that the requisite minimum 5 percent emissions reductions must be calculated from the total emissions for each precursor and for direct PM 2.5 contained in the most recent inventory for the ar ea, as described earlier in this section. In addition, the EPA proposes that these required reductions must then be achieved every year between the section 189(d) plan submission date and the new projected attainment date for the area. For example, assume it is 2025, and a Serious area has failed to attain the standard within 10 years of designation. Assume also that the most recent inventory available for a n area subject to section 189(d) is for the year 2023.

Th e 2023 inventory would serve as the base inv entory for determining the emission reduction requirement under section 189(d). I f the 2023 inventory indicates that

emissions of direct PM 2.5 from all sources in the area are 100 tons/day, then the area

would need to reduce emissions of direct PM 2.5 by 5% of the base inventory (in this example, 5% of the 2023 base inventory, or 5 tons/day ) each year until the area attains the NAAQS. Thus, in the first year following submission of the section 189(d) plan for the area, emissions of direct PM 2.5 could not exc eed 95 tons/day; in the second year, emissions could not exceed 90 tons/day, and so forth

. ’

c. (351) R eviewer r ecommend s clarifying that contingency measures that include outside the nonattainment area measures can be included for reaching the 5

percent req uired level as long as those measures are quantifiable, enforceable, replicable, and accountable.

Response : The section 189(d) requirement to reduce emissions by 5% per year expressly applies to sources “in the area” (i.e. sources in the nonattainment ar ea inventory ) . For this reason, emission reductions occurring outside the nonattainment area cannot be “credited” toward meeting the 5% per year emission reduction obligation. In addition, the 5% annual reductions after failure to attain are separate from any contingency measures that may have existed for failure to attain or meet reasonable progress requirements for earlier years.

16. Quantitative milestones.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 14

- a. R eviewer r ecommend s allowing a nonattainment area that has decreased emissions by greater than 15 per cent within a 3 year period to carryover that additional decreased emission to the next quantitative milestone.

Response : To address this comment, we have added the sentence below to the paragraph on page 34 5 :

“Although section 189(d) requires that a state develop measures that will obtain annual emissions reductions of “not less than 5 percent” from the most recent inventory, the EPA interprets this language to authorize states to elect to front

- load emissions reductions in earlier years and still me et the 5 percent per year requirement.

The EPA believes that interpreting the statute in this way will encourage states to implement measures earlier, where possible, rather than delay implementation of measures merely to assure that the 5 percent requirem ent can be met in later years. Early reductions of this kind would also be accounted for in state submittals to show they are meeting quantitative milestones every three years. Consistent with its past action to approve a Serious area nonattainment plan fo r the San Joaquin Valley (CA)

PM 10 nonattainment area under section 189(d), the EPA therefore proposes and seeks

comment on an approach to allow states to carry forward any emissions reductions beyond the required minimum 5 percent in a given year to the n ext year as a means to encourage states to achieve emissions reductions as quickly as possible. 1

17. Contingency measures for Serious nonattainment areas that have failed to attain.

a. Re viewer re commend s clarifying why contingency measures should be required when those contingency measures would have already been instituted for failure

to meet the RFP for the Serious nonattainment area.

Response : Section 172(c)(9) of the CAA requires contingency measures to be implemented if an area fails to meet RFP or fail s to attain the standard:

“(9) Contingency measures. Such plan shall provide for the implementation of specific measures to be undertaken if the area fails to make reasonable further progress, or to attain the national primary ambient air quality standar d by the attainment date applicable under this part. Such measures shall be included in the plan revision as contingency measures to take effect in any such case without further action by the State or the Administrator.”

If the state is require d to imple ment contingency measures for failure to meet
RFP, it must establish new contingency measure in case it late r fail s to attain the

standard or demonstrate RFP. The state should be able to institute new contingency measures before the next event that may t rigger a requirement to implement such measures

.

1 69 FR 30006 ( May 26, 2004 )

.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 15

- 18. Time

- frame for attainment for Serious nonattainment areas that have failed to

demonstrate attainment.

a. Re viewer re commend s providing additional clarification why 5 years (consistent with CAA section 172(a)(2 )) should be followed for demonstrating attainment

and why EPA is not considering 6 or 10 years for demonstrating attainment (consistent with CAA section 188(c)(1) and (2) that are specifically related to PM).

Response : C hanges have been added to this pa ragraph on page 35 7 to address

this comment:

“As previously discussed, section 189(d) requires a minimum 5 percent

annual reduction in emissions of direct PM 2.5 and PM 2.5 precursors until the area attains the relevant NAAQS. However, neither section 189 (d) nor other sections in subpart 4 explicitly establish or provide the authority to establish a new attainment date for the area; and other Subpart 4 attainment date provisions for Moderate or Serious areas are not applicable to areas in this situation. T herefore, once an area is beyond the attainment dates that Congress specified in subpart 4

for the PM 10 NAAQS, the EPA must look to the existing provisions of the CAA to provide authority for a new attainment date. Sections 179(d)(3) and 172(a)(2) provide generally applicable attainment dates that fill the gap in the statute left for areas subject to the requirements of section 189(d). T h us, for a PM 2.5 nonattainment area subject to section 189(d), th e EPA must establish a new

attainment date

, and must do s o according to the provisions of section 179(d)(3) and 172(a)(2). EPA has followed this same approach in the past for PM 10 nonattainment areas governed by subpart 4 nonattainment requirements.”

Footnote added here: For example, see the Federal Register n otice from June 6,

2007 (72 FR 31183) in which EPA finds that the Phoenix PM10 Serious nonattainment area failed to attain the standard by the 2006 attainment date. The notice states that the new attainment date is established under section 179(d)(3).

19. Def inition of stationary source.

a. Commenter recommends providing additional explanation and guidance of how stationary sources relate to agricultural production operations.

Response : We do not believe that it would be appropriate to revise the draft preambl e to provide “explanation and guidance of how stationary sources relate to agricultural production operation” in light of ongoing commitments and agreements EPA already has

in this area. As you know, we currently have an Air Quality Memorandum of

Understan ding with the USDA in which EPA will work in cooperation with the USDA in developing relevant national policy and guidance documents regarding agricultural production operations. In addition, EPA has a consent agreement with animal feeding operations ( AFO s ) to conduct a nationwide study to establish a better understanding of

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 16

- the AFO air emissions so that the EPA could publish emission

- estimating methods for

AFOs.

20. Major source thresholds for PM 2.5 precursors. (380)

a. Re viewer re commend s modifying EPA’s pol icy on preferred ratios for major

source threshold determinations for PM 2.5 precursors related to sulfur dioxide ( SO 2 ) and nitrogen oxides ( NO X ) . Specifically, the EPA believes that the preferred ratios in the 2008 PM 2.5 NSR Rule were not conservative eno ugh (page 374). However, not considering the relative effect of PM 2.5 precursors to direct

PM 2.5 puts an undue burden on potential sources of PM 2.5 precursors and sets a de facto more protective air quality standard than for direct PM 2.5 sources

.

Respon se : It is not clear what is meant by “modifying EPA’s policy on preferred ratios for major source threshold determinations....” As explained in the draft preamble, the policy on preferred ratios that the EPA set forth in the 2008 PM2.5 NSR Implementation Ru le was developed “ for purposes of interpollutant offset trading, whereby a source could obtain reductions of a PM 2.5 precursor to offset

an increase of direct PM 2.5 emissions or another PM 2.5 precursor based on the “preferred” offset ratios.” Arguably, suc h ratios , if approvable, could potentially

also have been applied to the setting of major source thresholds for the individual PM2.5 precursors

. However, we indicated in a subsequent 2011 memo that we could no longer support the preferred offset ratios as being presumptively approvable in state implementation plans. 2 Similarly, while we generally agree with the comment that precursor thresholds should reflect the relative effect of the individual precursor on ambient PM2.5 levels, we do not currently have a sufficient technical basis to prescribe specific higher thresholds by rule . We believe that the preamble adequately explains the technical and legal impediments and requests public comments as to how to best address this issue.

b. (376) Reviewer recommends adding a discussion of whether volatile organic compounds ( VOC ) and ammonia (NH 3 ) emissions (the other PM 2.5 precursors not mentioned above) should be considered at higher levels than direct PM 2.5 for major source thresholds.

Response : The preamble dis cussion is written so that it pertains to all PM2.5 precursors. NOx and SO2 are specifically mentioned in one segment of the discussion

2 See memorandum from Gina McCarthy, EPA Assistant Administrator for Air and Radiation, to Regiona l Office Air Division Directors, “ Revised Policy to Address Reconsideration of Interpollutant Trading Provisions for Fine Particles (PM2. 5 ) , issued on July

2 1, 2011. The memo indicated that, “First, upon re

- examination of the original data, we believe

that the original preferred ratios are not sufficiently representative of conditions in all areas of the country..... Second, we have determined that the ratios defined in the 2008 preamble are generally not suitable for application to offsets that address viola tions of the 24

- hour primary PM2.5 NAAQS.”

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 17

- because the preferred ratios set forth in the 2008 PM2.5 rule addressed those two

precursors. T he overall discussion and request for comments pertain to any PM2.5 precursor, which would also include VOC and ammonia.

21. Planning requirements not suspended with a Clean Data Determination (CDD)

a. Reviewer recommends providing additional clarification why certain planning requirem ents are not suspended with a CDD.

Response : We have added the underl ined text below to page 4 1 3 to clarify why certain requirements are not suspended with a CDD. We have also added a footnote referencing the PM2.5 clean data policy issued in 2004.

“1. What is a clean data determination? The EPA’s interpretation of the CAA applies when the agency, after notice and comment rulemaking, issues a “clean data determination” (CDD), in which it determines that a specific nonattainment area has attained the re levant standard. For such areas, the EPA interprets the CAA as suspending the state requirements to submit to the EPA the planning elements of an attainment plan related to attaining the NAAQS for as long as the area continues to attain the

standard. 3 Thes e planning elements generally include reasonable further progress (RFP) requirements, attainment demonstrations, RACM/RACT, nonattainment area contingency measures, and other state planning requirements related to the attainment of the NAAQS. (Add footnote here: See December 14, 2004 memorandum from Steven D. Page, Director, EPA Office of Air Quality Planning and Standards, entitled “Clean Data Policy for the Fine Particle National Ambient Air Quality Standards.” Available at: http://www.epa.gov/airquality/ urbanair/sipstatus/docs/pm25_clean_data_policy_1 4dec2004.pdf) The suspension of the obligation to submit applies regardless of when the plan submissions are due. The CDD does not suspend CAA EPA planning requirements that are independent of helping the ar ea achieve attainment, such as the requirements to submit an emissions inventory and nonattainment new source review requirements. The emission s inventory is a basic compilation of information used to characterize the sources of emissions of

the nonattainm ent area. Section 172(c)(3), the statutory provision requiring submission of an emissions inventory, is not tied to attainment of the NAAQS, unlike the attainment planning provisions which are suspended by a CDD. A base year inventory continues to be relev ant to a nonattainment area that is attaining

3 In the context of CDDs, the EPA distinguishes between attainment planning requirements of the CAA, which relate to the attainment demonstration for an area and related control measures for bringing an area into attainment for a given NAAQS as expeditiously as practicable, and other types of requirements, such as permitting requirements under the NNSR program, and any specific control requirements independent of those strictly needed to ensure timely attainment of a given NAAQS.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 18

- the NAAQS and has obtained a CDD because, for example, the inventory is a

necessary component to an approvable redesignation request

. In addition , in the event the air quality in the area exceeds the standard i n a subsequent year

, the state would be obligated to submit an attainment demonstration and other planning elements for the area , and a base year inventory would need to be available immediately in order for the state to submit an approvable attainment pl an expeditiously. Similarly, t he new source review requirement is not suspended

because section 172(c)(5) is not tied to attainment of the NAAQS, and an area with a CDD is still designated nonattainment

. N NSR permitting is required in

each nonattainment are a until the area is redesignated to attainment .”

22. Guidance for stationary source monitoring. (4 58 )

a. Reviewer recommends modifying this section as it does not appear to be related to the rest of the rulemaking. This appears to be an information collection r equest that is related to a future potential guidance update that is not tied to this specific rulemaking effort.

Response : While we agree that the discussion is not directly associated with any particular requirement or information collection mandate of this rul e, the EPA prefers to leave the discussion in to further its implementation efforts in partnership with states. J ust as a wood smoke reduction plan (mentioned in the preceding section K) can provide enforceable measures that reduce PM2.5 emissions, so can improved stationary source emissions monitoring. Moreover, to the extent that we receive the requested data, our sharing of current, state

- of

- the

art best practices to reduce PM2.5 emissions through improved emissions monitoring will help enable state age ncies to develop source

- or area

- specific,

cost

- effective strategies for their SIPs.

23. EO 12866 and EO 13563

. (486)

a. Re viewer re commend s clarifying the statement that EPA submitted the action to the Office of Management and Budget (OMB) for review in 2011.

Response : We have revised the text here to be consistent with the latest action development process (ADP) templates, and eliminated the parenthetical “ (76 FR 3821, January 21, 2011)

. ”

Under Executive Order 12866 (58 FR 51735, October 4, 1993), this act ion is a "significant regulatory action” because it raises novel policy issues. Accordingly, the EPA submitted this action to OMB for review under Executive Orders 12866 and 13563 (76 FR 3821, January 21, 2011) and any changes made in response to OMB recom mendations have been documented in the docket for

this action.

This action is a significant regulatory action that was submitted to the Office of Management and Budget (OMB) for review because it raises novel policy issues.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 19

- Any chang es made in response to OMB recommendations have been documented

in the docket.

b. Reviewer recommends providing benefits and costs for this proposed rule within a regulatory impact analysis even if those benefits and costs are at the state level.

Response : A Regulatory Impact Assessment (RIA) was developed for the 2012 PM2.5 NAAQS. As has traditionally been done for NAAQS rulemakings, the EPA conducted this RIA to provide the public with illustrative estimates of the potential costs and health and welfare b enefits of attaining the revised annual standard. This document is available on the PM2.5 NAAQS website at: http://www.epa.gov/ttn/ecas/regdata/RIAs/finalria.pdf

.

EPA commonly provide s a regulatory impact analysis for NAAQS revisions, but

not for implementation rules.

24. Paperwork Reduction Act

.

a. (486) Reviewer recommends clarifying why states without any nonattainment area would not be required to submit any information to the EPA for t his rule.

Response : To address this comment, we have added a sentence indicating that only states with nonattainment areas would be required to submit SIPs under this rule. We have also revised the text to be consistent with the latest PRA template

, and made a few clarifying edits

.

“ The information collection activities in this proposed rule have been submitted for approval to the O ffice of Management and Budget (O MB ) under the

PRA. The Information Collection Request (ICR) document prepared by the EPA

h as been assigned the EPA ICR number 2258.03, OMB Control No. 2060

- 0611. You can find a copy of the ICR in the docket for this rule, and it is briefly

summarized here.

The EPA is proposing this PM 2.5 NAAQS SIP Requirements Rule to
describe the CAA require ments that must be met by states with nonattainment areas required to develop SIPs for attaining and maintaining the NAAQS. The intended effect of the SIP Requirements Rule is to provide certainty to states regarding their planning obligations such that st ates may begin SIP development. Only states with nonattainment areas are required to submit SIPs under this rule. ”

b. (487) Reviewer recommends providing additional basis for the estimated labor hours required and the estimated labor costs.

Response : Addi tional information about the estimated labor hours and estimated labor costs can be found in the supporting statement of t he Information Collection Request (ICR) document

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 20

- prepared by the EPA for this rulemaking. The ICR has been assigned the EPA ICR number

225 8.03, OMB Control No. 2060

- 0611, and it will be available in the docket for this rulemaking. ”

S pecific Comments

1. Page 22.

a. Commenter recommends revising the statement “For example, PM 2.5 concentrations are highest in the West and Southeast.” However, Table 2 shows that concentrations are highest in the West and Central.

Response : See response for item 2 below.

2. Page 23.

a. Commenter recommends deleting Table 2 as the regional information comes from 1 to 34 stations within a region and may lead to conclu sions that are incorrect

. Because of so few stations the regional values are not statistically reliable and may not be representative of the region

.

Response : We think that there is still benefit in including information in the preamble about PM2.5 compo sition for different regions of the country. For this reason, instead of deleting table 2, we have instead modified it to include significantly more data, and better representation of the range of values in each region. With this additional data, we believ e there will be less chance for the

reader to draw incorrect conclusions. The table now contains data from all of the PM2.5 speciation sites in the Chemical Speciation Network. In addition, the information has been expanded to include the minimum and maxim um concentrations for sites within in each region (in addition to the mean concentration for all sites in each region). This additional information provides a more complete assessment of the full range of observed PM2.5 and species

concentration s within t he monitoring network.

Table 2 and the introductory text now appear on page 23

- 25 as follows:

“ 4. Fine P articulate C omposition B y L ocation Table 2 shows regional 3

- year mean concentrations (2009

- 2011) of PM 2.5 and its main components at sites in the Che mical Speciation Network (CSN)

. 4 In addition to the mean values for all sites in each region, the table includes the minimum and maximum observed PM 2.5 and species concentrations for sites within each region. These data illustrate broad observed spatial

4 The organic matter (OM) values in Table 2 were calculated by multiplying the measured organic carbon (OC) concentrations by 1.6 (Turpin and Lim (2001), Aerosol Science and Technology, 35, 602

- 610). PM 2.5 concentrations come f rom measurements of the Federal Reference/Equivalance Methods (FRM/FEM) rather than from the CSN PM 2.5 measurement.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 21

- pa tterns across the U.S. in PM 2.5 concentrations and its composition. For example, PM 2.5 concentrations are highest on average in the Central and West regions . Sulfate mass comprises a larger fraction of PM 2.5 than nitrate mass in the northeastern U.S., wher eas nitrate has a greater
contribution than that of sulfate in the West. OM is the dominant component in all regions except the central U.S., with the highest concentrations of OM on average found in the West, Northwest and Southeast. On a percentage basis , the concentrations of EC and crustal material are relatively low throughout all regions of the U.S. compared to the other major PM components. The composition of PM 2.5 also varies between urban and rural areas. This is reflective of

the distribution of urban and regional emission sources, atmospheric reactions and transport of fine particles. More details about the spatial distribution and origins of PM 2.5 components can be

found in the docket for this proposal

. 5

Table 2. PM 2.5 Chemical Composition Data at 2009

- 2011 Nonattainment Sites

Source: EPA Speciation Trends Network

Region Statistic Concentration (μg/m 3 )

SO 2 −4 NO −3 O M EC CrM PM 2.5
Central Min (μg/m 3 ) 1.46 0.3 2.73 0.31 0.01 8.92

Mean (μg/m 3 ) 2.69 1.49 3.57 0.68 0.26 11.63

Max (μg/m 3 ) 4.19 3.34 4.81 1.1 1.0 13.51

N 61 61 50 50 61 42

East North Central Min (μg/m 3 ) 0.83 0.38 1.97 0.19 0.01 6.03

Mean (μ g/m 3 ) 1.68 1.8 2.84 0.48 0.19 9.86

Max (μg/m 3 ) 2.51 3.57 3.69 0.79 0.61 11.87

N 29 28 20 20 28 23

North East Min (μg/m 3 ) 0.58 0.12 1.74 0.14 0 4.42

Mean (μg/m 3 ) 2.06 0.97 3.14 0.69 0.17 9.33

Max (μg/m 3 ) 5.12 2.26 5.05 1.69 0.52 15.05

N 59 59 39 39 59 46

North West Min (μg/m 3 ) 0.24 0.05 2.91 0.42 0.01 6.06

Mean (μg/m 3 ) 0.54 0.4 5.02 0.81 0.15 8.33

Max (μg/m 3 ) 1.09 1.79 8.44 1.25 0.53 10.96

N 33 33 13 13 33 14

South Min (μg/m 3 ) 0.88 0.18 1.36 0.12 0.02 5.22

Mean (μg/m 3 ) 2.06 0.8 3.32 0.57 0.5 10.05

Max (μg/m 3 ) 3.08 1.67 5.1 1.48 2.38 14.27

N 36 27 23 23 36 23

South East Min (μg/m 3 ) 1.6 0.2 1.75 0.37 0.01 6.76

Mean (μg/m 3 ) 2.39 0.53 4.12 0.63 0.26 10.77

Max (μg/m 3 ) 4.33 1.51 5.71 1.2 0.85 13.38

N 44 43 30 30 43 29

South West Min (μg/m 3 ) 0.34 0.07 2.34 0.46 0.02 5.3

5 Reff and Rao, Memo to the docket, 2013

.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 22

- Mean (μg/m 3 ) 0.63 0.49 3.01 0.7 0.5 7.93

Max (μg/m 3 ) 1.13 2.65 4.39 1.04 1.96 9.73

N 46 46 11 11 46 12

West Min (μg/m 3 ) 0.33 0.08 1.79 0.52 0.01 6.84

Mean (μg/m 3 ) 0.9 1.4 5.22 0.85 0.32 11.49

Max (μg/m 3 ) 2.0 8 5.14 10.27 1.56 1.05 16.57

N 44 44 20 20 44 21

West North Central Min (μg/m 3 ) 0.29 0.06 1.22 0.09 0 3.23

Mean (μg/m 3 ) 0.67 0.48 3.16 0.44 0.22 7.25

Max (μg/m 3 ) 1.79 2.02 8.28 1.21 0.53 13.72

N 30 30 7 7 30 10

3. Page 39.

a. Commenter recommends pro viding additional information for determining that reducing regional SO 2 and local sources of carbon in the East and local sources of nitrate and carbon in the West will be most effective in reducing PM 2.5 concentrations . The additional information could be used by states to alleviate burden in relation to precursor demonstrations and attainment planning.

Response : The general statement s in the draft preamble noted above were based on a

basic evaluation of PM2.5 composition data from different regions o f the country. These data are already publicly available. However, because the general observations in the text may be misinterpreted , we recommend that w e delete the following sentences from page 41

- 42 :

“ For instance, in the East, regional pollution con tributes to more than half of

total PM 2.5 concentrations. Rural background PM 2.5 concentrations are high in the East and are somewhat uniform over large geographic areas. These regional concentrations come from emission sources such as power plants, natura l sources and urban pollution and can be transported hundreds of miles. They also reflect to some extent the denser clustering of urban areas in the East as compared to the West. In the West, much of the measured PM 2.5 concentrations tend to be locally der ived. These

concentrations come from emission sources such as wood combustion and mobile sources. In general, these data indicate that reducing regional SO 2 and local sources of carbon in the East,

and local sources of nitrate and carbon in the West will b e most effective in reducing PM 2.5 concentrations. This proposal takes into account the variability in the nature and sources of PM 2.5 in different nonattainment areas and the need that states have to be able to develop control strategies for direct PM 2.5 and PM 2.5 precursors that reflect the variable nature of their sources. ”

4. Page 107.

a. Commenter recommends clarifying how attainment demonstration modeling emissions inventories may not be consistent with the emissions inventories

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 23

- developed for the nonattain ment area and how the nonattainment area emissions inventories are used for the attainment demonstration modeling.

Response : We have revised the text in this section to address this comment. The following text will replace the relevant preamble section a round page 10 9 :

“ 7. How do emission inventories support modeling for attainment demonstrations? This section attempts to clarify the difference between the inventories required to be a part of a state’s Moderate area attainment plan submission (as describ ed earlier) and other modeling inventories that are also relevant for attainment planning. While the EPA is not proposing additional modeling inventory requirements in this rule ( i.e. , for which a state must submit an emissions inventory to the EPA), to me et the attainment demonstration requirements of CAA sections 189(a)(1) and 189(b)(1), states will need to submit an attainment demonstration (which includes air quality modeling) to show how the area will either attain the NAAQS by the applicable attainmen t date or that the area cannot attain by the attainment date. The modeled attainment demonstration requirements for Moderate areas are described fully in Section IV.E of this preamble. As part of this demonstration, the EPA presumes that states will need t o prepare attainment demonstration modeling inventories for both a modeled base year and projected attainment year. Respectively, these are called the base year (baseline) inventory for modeling

and the attainment projected inventory for modeling

. These in ventories contain emissions for all regions ( i.e. , not just the nonattainment area) within the modeling domain being used for the attainment plan modeling demonstration, which typically includes counties and states outside of the nonattainment area. They i nclude detailed spatial and temporal elements needed to support air quality modeling. States should follow the requirements laid out in Section IV.E of this preamble and the procedures described in the SIP Emissions Inventory Guidance and the Air Quality M odeling Guidance to meet the minimum requirements for documentation and emissions summaries supporting modeling demonstrations. The base year inventory and projected attainment year inventory include emissions from only within the nonattainment area. The E PA expects that modeling inventories will be

consistent with those nonattainment area inventories; however, some exceptions may exist. Where possible, the nonattainment area base year and projected attainment year inventories can be a sum (for annual data) or average (for PM2.5 season

- day data) of day

- specific or hour

specific data used for modeling. In some cases, however, this approach may not be sufficient for modeling purposes. For example, greater spatial and temporal detail are needed for on

- road

mobi le modeling inventories as compared to the base year inventory for the nonattainment area.

For the nonattainment area base year inventory, one goal is to allow for the repeatability of the approach in order to create average, seasonal, or annual inventori es for use in rule requirements, such as reasonable further progress or conformity demonstrations. That goal is not necessarily compatible with the modeling need for greater spatial and temporal detail. In cases where some differences are unavoidable, air agencies should attempt to pro mote consistency where feasible.

b. Commenter recommends providing additional information on how emissions of

PM 2.5 and PM 2.5 precursors outside of the nonattainment area may be affected (i.e., regulated or controlled) as a resu lt of the modeling demonstrations.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 24

- Response : The modeling demonstration typically will employ a modeling domain that extends beyond the boundaries of the nonattainment area, and the state commonly will conduct modeling runs to assess the effectiveness o f certain emission reduction measures on sources throughout the entire modeling domain. The state has jurisdiction over emissions sources throughout the entire state, and it has the ability to adopt regulations that apply to sources across the whole state in order to help address multiple air quality related issues at the same time. For example, some states have adopted statewide regulations to reduce SO2, NOx, direct PM2.5, and mercury from power plants to efficiently address multiple air pollution problem s (i.e. PM2.5, ozone, mercury deposition) and to provide a level regulatory “playing field” for a particular industry or sector. This implementation rule provides flexibility to the state to determine the most appropriate mix of

control measures needed to bring an area into attainment with the NAAQS “as expeditiously as practicable

. ” That said, if potential control measures are available in the state on sources located either within or outside the nonattainment area, and

this collection of control measures would enable the area to attain the standard at least one year sooner, then the state would be obligated to adopt provisions to require such emission reductions.

5. Page 111.

a. Reviewer r ecommend s modifying “States can alternatively develop superior state

spe cific nonroa d emissions estimates . . . .” to state “States can alternatively develop technologically equivalent or superior state

- specific nonroad emissions

estimates . . . .”

Response : We have added the recommended text to the sentence noted above on page 11 4

.

6. Page 134.

a. Re viewer re commend s removing brackets from “in the area” quotation with respect to the “nonattainment area” and providing a footnote of the court decision and how it applies.

Response : To address t his comment, w e have revised the se ntence on page 138 as follows :

“ In that proposal, the EPA explained that g iven the explicit wording of section 172(c)(1) that sources “ in the [nonattainment] area” (i.e., in the nonattainment area) must at a minimum adopt RACT controls for that area, the agency believes that it is no longer appropriate to presume that this requirement is satisfied merely based upon the participation of a source in a regional cap

- and

- trade program.

F ootnote 95 provides a reference to the court decision and how it applies.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 25

- 7. Page 137.

a. Re viewer re commend s providing additional discussion on the economic feasibility determination recommended in the 2007 PM 2.5 rule.

Response : S ee response to comment 8a under “General Comments.”

8. Page 139.

a. Re viewer re commend s adding to the list: 8. Impact on jobs and 9. Cumulative impacts to the source not considered above (e.g., delays in maintenance or other potential safety

- related actions).

Response : See response to comment 8a above.

9. Page 327.

a. Re viewer re commend s clarifying that “in writin g” includes electronic submittals within Step 5.

Response : We have deleted the two references in this document to submitting

information to EPA “in writing ” ( both of which appear in this section on submitting Serious area attainment date extension reques ts on page 332 ) because states already commonly send different types of submittals to EPA via electronic means. We have removed the phrase “in writing” to avoid any confusion.

10. Rule Language

a. (507) §51.100

– reasonable further progress is defined as “annual incremental

reductions in emissions . . . .” Re viewer re commend s clarifying whether periodic

step

- down functions are included within RFP.

Response : Th is type of clarification does not need to be included in rule language on RFP

, as the “step

- wise funct ion” and the “generally linear reduction” approaches are both alr eady discussed in the preamble around page 190.

b. §51.1006(a)

– re viewer re commend s removing or revising the second sentence starting with “ The technical analysis could include . . . .” as thi s language is more appropriate for guidance documents or discussion within the preamble.

Response : We have r emoved the sentence in question on page 528.

c. (520) §51.1007(d)

– reviewer recommend s removing or revising this subpart as this language is more appropriate for guidance documents or discussion within the preamble.

Response : We have r emoved the sentence in question on page 529.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 26

- d. §51.1008

– re viewer re commend s clarifying why there are timing requirements within §51.1008(b) (3) for Serious nonattai nment areas and not for Moderate nonattainment areas within §51.1008(a).

Response : We have removed the timing requirements under para graph 51.1008(a) and revised the proposed regulations at 51.1003 to clarify the timing requirements for different emissio ns inventory submissions for different types of

PM2.5 nonattainment areas.

T ypographical Comments

1. Page 4 0

.

a. Commenter recommends ensuring that:

i. Tier 2 Light

- Duty vehicle standards be cited instead of Tier 3

ii. Green House Gas standards for Light

- Duty an d Heavy

- Duty vehicles do

not need to be cited.

Response : We have revised the list on page 43 of national regulations and standards that will help PM2.5 nonattainment areas in reaching attainment. The

Tier 3 vehicle and fuel standards were finalized in 2014 and emission reductions should begin in 2017, thus we feel it is appropriate to include this rule on the list. The “Green House Gas Standards” referred to by the reviewer are not referenced.

The revised text reads as follows:

“ The national rules tha t will help states meet their attainment dates include, but

are not limited to: the Tier 2 Light

- Duty Vehicle Rule; the Tier 3 Tailpipe and Evaporative Emission and Vehicle Fuel Standards ; the Heavy

- Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements; the Clean Air Nonroad Diesel Rule; the Regional Haze Regulations and Guidelines for Best Available Retrofit Technology Determinations; the NO
x Emission

Standard for New Commercial ....”

b. Commenter recommends clarifying if the He avy Duty rule is the Tier 2 Heavy Duty Diesel rules.

Response : We have referred to these rules as “ the Heavy

- Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements ,” as they are referred to in our fact sheets.

c. Commenter recommends updating footnote 47.

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 27

- Response : The purpose of the reference to the 1991 NAPAP report in footnote 47 is to show that evidence of long

- range transport of particulate matter has been

documented and well

- understood for many years. For this reas on, we are keeping

footnote 47 as is.

2. Page 242.

a. Add additional “)” after “section 172(c)(6)”.

Response : This change has been made.

3. Page 518.

a. Recommend revising §51.1005(c) as there appears to be words missing.

Response : We have revised this paragrap h on page 527 to provide more clarity.

“ (c) Serious nonattainment areas subject to CAA section 189(d) for failing to attain by the applicable Serious area attainment date. If A state with a Serious area

that fail s ed to attain a particular PM 2.5 NAAQS by t he applicable Serious area

attainment date

, the area is and is therefore then subject to the requirements of section 189(d) of the Act , and, for this reason, the state is prohibited from requesting an extension of the applicable Serious area attainment dat e for such

area

. ”

4. Page 536.

a. Part of the first sentence for §51.1011(a) and (b) is underlined and should be

removed.

Response : Change has been made.

5. Reviewer recommends defining the following terms and ensuring that all acronyms used

within the preambl e are also provided with in the preamble glossary of terms and

acronyms :

a. FRM

b. FEM

c. NESHAPs

Response : We have revised the glossary to address these terms.

6. Reviewer recommends revising all cases where the term “whether or not” is used to state

“whether”. F or example, on page 398, the sentence, “The requirements differ depending

on whether or not the nonattainment area is considered a metropolitan area.” (emphasis added). Should be revised to state, “The requirements differ depending on whether the

nonattai nment area is considered a metropolitan area.”

### EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866/13563 Interagency Review. Subject to Further

Policy Review. Final: 1/2 3 /2015

- 28

- Response : This change has been made on page 405 ; and it was only case of “whether or not” that appeared in the document.