Comment and Response Document

Proposed Revisions to the Infrastructure State Implementation Plans for the 

2008 8-Hour Ozone National Ambient Air Quality Standard (NAAQS); 

2010 1-Hour Nitrogen Dioxide NAAQS; 

2010 1-Hour Sulfur Dioxide NAAQS; and 

2012 Annual Fine Particulate Matter NAAQS; 

and Proposed SIP Revision for Clean Air Act Section 128 for All NAAQS

July 2014

Bureau of Air Quality

Department of Environmental Protection
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On May 3, 2014, the Pennsylvania Department of Environmental Protection (DEP) published a 

notice of public hearing and commenced a 35-day written comment period on the proposed 

revisions to the Infrastructure State Implementation Plans (i-SIPs) for the 2008 8-Hour Ozone 

NAAQS, 2010 1-Hour Nitrogen Dioxide NAAQS, 2010 1-Hour Sulfur Dioxide NAAQS and 

2012 Annual Fine Particulate Matter NAAQS; and the proposed SIP revision for Clean Air Act 

Section 128 for all NAAQS (all applicable statewide) (44 Pa.B. 2707). No member of the public 

requested a public hearing so the scheduled hearings were cancelled and notice was posted on 

DEP’s website. The comment period closed on June 6, 2014.

This document summarizes the written comments received prior to the close of the public 

comment period. The list of commentators is set forth below:

COMMENTATORS:

1. Diana Esher

Director, Air Protection Division

U.S. Environmental Protection Agency - Region III

1650 Arch Street

Philadelphia, PA 19103-2029

2. Elizabeth Toba Pearlman

Office of Elizabeth Toba Pearlman

Sierra Club

1523 27th Street NW

Washington, DC 20007
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COMMENTS AND RESPONSES

NOTE 1: Commentator No. 2, the Sierra Club, frequently refers to DEP as ‘PaDEQ’ throughout 

the comment document. The DEP has never been known as PaDEQ, however. In DEP’s 

responses, DEP assumes that the commentator is referring to DEP when the commentator refers 

to PaDEQ.

NOTE 2: Commentator No. 2, the Sierra Club, frequently references elements that it asserts 

must be included in the SIP. DEP would like to clarify that everything that has been approved 

by EPA and codified in 40 CFR Part 52, Subpart NN, Section 52.2020, is Pennsylvania’s SIP, 

which includes but is not limited to numerous Pennsylvania regulations; Pennsylvania’s

Prevention of Significant Deterioration, New Source Review, and permitting programs; and 

Pennsylvania’s attainment demonstrations, maintenance plans, inventories, and other SIP 

revisions. Different types of SIP revisions address different requirements under the CAA, and 

are generally divided into ‘planning’ SIPs (including infrastructure SIPs), and ‘control strategy’ 

SIPs. Inclusion in Pennsylvania’s SIP is not limited to items listed in infrastructure SIP 

revisions. This note applies to all Responses to Commentator No. 2 in this Comment and 

Response Document.

COMMENTS:

1. COMMENT: 110(a)(2)(B) – In the discussion of how this element is addressed in part 

by the Allegheny County Health Department (ACHD) and Philadelphia Air Management 

Services (AMS), the proposed revisions state “The 30-day public comment period for the 

ACHD and Philadelphia AMS network design plans is provided by the EPA pursuant to 

40 CFR § 58.10(a)(2).” The public comment period for network design plans for these 

localities is provided by the localities and not by EPA. EPA does however review the 

plans and as indicated in the proposal, correspondence related to the reviews is included 

in Appendix A of the proposed submittals. (1)

RESPONSE: DEP agrees with commentator. The i-SIP revisions for the 2008 8-Hour 

Ozone NAAQS, 2010 1-Hour Nitrogen Dioxide (NO2) NAAQS, 2010 1-Hour Sulfur 

Dioxide (SO2) NAAQS and 2012 Annual Fine Particulate Matter (PM2.5) NAAQS have

been revised to reflect that both ACHD and AMS provide public comment periods on 

their respective proposed network design plans. The SIP revision also explains that, if 

the local agencies fail to provide a public comment period, a 30-day comment period 

would be provided by EPA pursuant to 

40 CFR 58.10(a)(2).

2. COMMENT: 110(a)(2)(D)(i) – EPA recognizes that there was likely an overlap in time 

during which these revisions were being readied and a legal opinion was issued. On 

April 29, 2014, the United States Supreme Court reversed the opinion of the D. C. Circuit 

Court in EME Homer City Generation, L. P. v EPA v, 696 F.3d7 (D.C. Cir. 2012) which 
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had vacated EPA’s Cross State Air Pollution Rule (CSAPR) and remanded the matter to 

the D. Dc. Circuit for further proceedings. (1)

RESPONSE: DEP has removed all language relating to 110(a)(2)(D)(i)(I) in the i-SIP 

revisions for the 2008 8-Hour Ozone NAAQS, 2010 1-Hour NO2 NAAQS, 2010 1-Hour 

SO2 NAAQS and 2012 PM2.5 NAAQS and will address the requirements of that section 

in a future SIP revision. 

3. COMMENT: 110(a)(2)(D)(i) – On April 30, 2014, EPA reissued its final limited 

approval of Pennsylvania SIP revision to implement the Commonwealth’s regional haze 

program for the first planning period through 2018 (79 FR 24340). EPA is currently 

reviewing the legal opinion discussed above for implications on the regional haze 

program. (1)

RESPONSE: DEP has revised the i-SIP revisions for the 2008 8-Hour Ozone NAAQS, 

2010 1-Hour NO2 NAAQS, 2010 1-Hour SO2 NAAQS and 2012 PM2.5 NAAQS to 

update the date EPA issued the limited approval of Pennsylvania’s regional haze SIP 

revision and to remove references to the earlier limited approval dated July 13, 2012, and 

the petition for review of it, filed on September 11, 2012.

4. COMMENT: SO2 Infrastructure SIP Revision – The document indicates in element 

F(iii) that “DEP also supplies EPA with an annual stationary source inventory for major 

emitters of NOX ... and VOC...”. If appropriate, the Commonwealth could indicate if it 

also includes sources that emit SO2. (1)

RESPONSE: DEP does not submit an annual stationary source inventory to EPA based 

on SO2 emissions. DEP does, however, include reporting requirements for SO2 in 

permits issued to stationary sources in the Commonwealth. Stationary facilities are 

required to submit an Annual Emission Statement (AES); nitrogen oxides (NOX), sulfur 

oxides (SOX), volatile organic compounds (VOC), course particulate matter (PM10), fine 

particulate matter (PM2.5), ammonia (NH3) and carbon monoxide (CO) emissions of 1.0 

ton per year or more per sub facility must be reported on a sub facility by sub facility 

basis. DEP supplies facilities with reporting instructions in the document “Instructions 

for Completing the Annual Emission Statement Reporting Forms – rev 11/2007” 

(DEP Document #2700-BK-DEP1936). All emissions reported on the AES are entered 

into DEP’s computer system: Air Information Management System / environment, 

Facility, Application, Compliance Tracking System (AIMS/eFACTS). The public can 

search the eFACTS system online at the website 

http://www.ahs.dep.pa.gov/eFACTSWeb/default.aspx to find facility specific reports or 

reports of all facilities emitting a specific pollutant. The public can request copies of 

permits or other non-confidential information by contacting DEP directly. Additionally, 

AIMS/eFACTS data is provided to the federal National Emission Inventory (NEI) 

database and to other state agencies and the public upon request. DEP revised the SO2

i-SIP revision to incorporate this information.
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5. COMMENT: PM2.5 Infrastructure SIP Revision – The document indicates in element 

F(iii) that “DEP also supplies EPA with an annual stationary source inventory for major 

emitters of NOX ... and VOC...”. If appropriate, the Commonwealth could indicate if it 

also includes sources that emit PM2.5. (1)

RESPONSE: DEP does not submit an annual stationary source inventory to EPA based 

on PM2.5 emissions. DEP does, however, include reporting requirements for PM2.5 in 

permits issued to stationary sources in the Commonwealth. Stationary facilities are 

required to submit an Annual Emission Statement (AES); nitrogen oxides (NOX), sulfur 

oxides (SOX), volatile organic compounds (VOC), course particulate matter (PM10), fine 

particulate matter (PM2.5), ammonia (NH3) and carbon monoxide (CO) emissions of 1.0 

ton per year or more per sub facility must be reported on a sub facility by sub facility 

basis. DEP supplies facilities with reporting instructions in the document, “Instructions 

for Completing the Annual Emission Statement Reporting Forms – rev 11/2007” 

(DEP Document #2700-BK-DEP1936). All emissions reported on the AES are entered 

into DEP’s computer system: Air Information Management System / environment, 

Facility, Application, Compliance Tracking System (AIMS/eFACTS). The public can 

search the eFACTS system online at the website 

http://www.ahs.dep.pa.gov/eFACTSWeb/default.aspx to find facility specific reports or 

reports of all facilities emitting a specific pollutant. The public can request copies of 

permits or other non-confidential information by contacting DEP directly. Additionally, 

AIMS/eFACTS data is provided to the federal National Emission Inventory (NEI) 

database and to other state agencies and the public upon request. DEP revised the PM2.5

i-SIP revision to incorporate this information.

6. COMMENT: The plain language and legislative history of the Clean Air Act require 

that Infrastructure SIPs must impose emission limits adequate to prevent NAAQS 

exceedances in areas not designated nonattainment. (2)

RESPONSE: DEP disagrees with the commentator and the commentator’s narrow 

interpretation of the CAA. An infrastructure SIP is only the first step in a state’s 

planning for attaining and maintaining a new or revised NAAQS. See Note 2, above. 

DEP believes the requirement in Section 110(a)(2)(A) of the CAA that the SIP provide 

for “implementation, maintenance and enforcement” means for purposes of Section 110 

that a state may rely on measures already in place to address the pollutant at issue or any 

new control measures that the state may choose to submit. This is consistent with EPA’s 

expressed interpretation of Section 110, as explained in EPA’s approval of the Delaware1

and Virginia2i-SIPs for the 2008 Ozone NAAQS.

3 DEP agrees with EPA that, in light of 

 

1. Approval and Promulgation of Air Quality Implementation Plans; Delaware; Infrastructure Requirements for the 

2008 Ozone National Ambient Air Quality Standards; U.S. Environmental Protection Agency; 79 FR 18644 

(April 3, 2014) hereafter referred to as the Delaware Ozone i-SIP approval.

2. Approval and Promulgation of Air Quality Implementation Plans; Virginia; Section 110(a)(2) Infrastructure

Requirements for the 2008 Ozone National Ambient Air Quality Standards; U.S. Environmental Protection 

Agency, 79 FR 17043 (March 27, 2014), hereafter referred to as the Virginia Ozone i-SIP approval.

3. See Delaware Ozone i-SIP approval Section III(C)(a) – Response 2 on pages 18648-18649 and Virginia Ozone 

i-SIP approval Section II(B)(1) – Response 2 on page 17047.
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the structure of the CAA, infrastructure SIPs are general planning SIPs to ensure that a 

state has adequate resources and authority to implement a NAAQS in general throughout 

the state and not detailed attainment and maintenance plans for each individual area of 

the state.4 The two legislative history references presented by the commentator only 

indicate that states should include enforceable emission limits in their SIPs (not 

specifically in their infrastructure SIPs) and do not address whether states are required to 

include maintenance plans for all areas of the state as part of the infrastructure SIP.5 

Additionally, the two legislative history references pertain to Section 110 as promulgated 

in 1970 and not to Section 110 as amended in 1990.

7. COMMENT: EPA regulations implementing the Clean Air Act require that 

Infrastructure SIPs impose emission limits adequate to prohibit NAAQS exceedances in 

areas not designated as nonattainment. The commentator cites 40 CFR § 51.112(a) to 

support this comment. (2)

RESPONSE: DEP disagrees. See Note 2 and the response to Comment 6, above. In 

addition, EPA has determined that 40 CFR § 51.112(a), cited by the commentator,

applies when states are developing control strategy SIPs, such as detailed attainment or 

maintenance plan SIPs.

6

 EPA considers i-SIPs to be general planning SIPs, not control 

strategy SIPs, and as such, the specific requirements of the section cited are not 

applicable.7 DEP agrees with EPA’s approach.

8. COMMENT: Prior EPA interpretations of the Act require that Infrastructure SIPs 

impose emission limits adequate to prohibit NAAQS exceedances in areas not designated 

nonattainment. The commentator cites two EPA actions in support of this comment, 

namely EPA’s partial approval and partial disapproval of a Missouri SIP revision 

pertaining to the previous (1971) SO2 standard (71 FR 12623 (March 13, 2006)), and

EPA’s proposed disapproval of Indiana’s SO2 SIP revision (78 FR 78720 

(December 27, 2013)). (2)

RESPONSE: DEP disagrees that prior EPA interpretations of the CAA require that 

infrastructure SIPs impose emission limits adequate to prohibit NAAQS exceedances in 

areas not designated nonattainment. See Note 2 and the responses to Comments 6 and 7, 

above. It is clear from EPA’s final rule on the Missouri SIP revision that the agency was 

taking action on an attainment (or control strategy) SIP revision, and not on an i-SIP 

revision.8 Therefore, EPA’s action is not applicable to the i-SIPs being submitted to EPA 

 

4. See Delaware Ozone i-SIP approval Section III(C) – Response 1 on page 18648 and Virginia Ozone i-SIP 

approval Section II(B)(1) – Response 1 on page 17046. 

5. See Delaware Ozone i-SIP approval Section III(C)(b) – Response 3 on page 18649 and Virginia Ozone i-SIP 

approval Section II(B)(2) – Response 3 on page 17047. 

6. See Delaware Ozone i-SIP approval Section III(C)(d) – Response 5 on page 18650 and Virginia Ozone i-SIP 

approval Section II(B)(4) – Response 5 on pages 17048-17049. 

7. See footnote 4.

8. See Delaware Ozone i-SIP approval Section III(C)(e) – Response 6 on page 18651 and Virginia Ozone i-SIP 

approval on page 17049.
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by DEP. EPA’s proposed disapproval of Indiana’s SO2 SIP revision is a proposal and 

cannot be used as evidence of final EPA actions. It is also clear in Section I of that 

proposal, entitled, “What is the background for this action?”, that EPA is proposing 

disapproval of the Indiana SIP revision because it fails to meet the requirements of CAA 

Section 110(l), not Section 110(a). In addition to that, EPA’s proposed action on the 

Indiana SIP revision relates to a proposed revision to Indiana’s approved SO2 attainment 

plan, not the SO2 i-SIP,

9

and is therefore not applicable to the i-SIPs being submitted to 

EPA by DEP.

9. COMMENT: Supreme and Appellate Court opinions hold that Infrastructure SIPs must 

impose emission limits adequate to prohibit NAAQS exceedances in areas not designated 

nonattainment. (2)

RESPONSE: DEP disagrees. None of the cases cited by the commentator support the 

commentator’s contention regarding infrastructure SIPs. DEP incorporates EPA’s 

analysis of the cases in EPA’s final actions on the Delaware Ozone i-SIP approval and 

the Virginia Ozone i-SIP approval.10 See Note 2 and the responses to Comments 6

through 8, above.

10. COMMENT: Pennsylvania’s draft SO2 I-SIP fails to include enforceable one-hour SO2

emission limitations to ensure attainment and maintenance of the primary SO2 NAAQS. 

Pennsylvania’s draft SO2 I-SIP must be revised to include enforceable one-hour SO2

emission limitations for sources currently allowed to cause exceedances of the NAAQS. 

(2)

RESPONSE: DEP disagrees. See Note 2 and the responses to Comments 6 through 9, 

above. In addition, the CAA requires states with areas designated as nonattainment under 

a NAAQS to submit an applicable implementation plan meeting the requirements of 

Part D of the CAA by deadlines established in the CAA or EPA regulations. According 

to EPA’s “Guidance on Infrastructure State Implementation Plan (SIP) Elements under 

Clean Air Act Sections 110(a)(1) and 110(A)(2)” issued in September 2013, “emission 

limitations and other control measures needed to attain the NAAQS in areas designated 

as nonattainment for that NAAQS will be due on a different schedule from the 

Section 110 infrastructure elements and will be reviewed and acted upon with regard to 

approvability for the specific purpose of such an attainment plan under CAA 

Title I Part D through a separate process at a later time.”11 DEP is not adding new 

emission limitations in the i-SIPs being submitted to EPA; emission limitations will be 

addressed, as necessary and appropriate, through mechanisms that may include but are 

 

9

See footnote 8. 

10 See Delaware Ozone i-SIP approval Section III(C)(c) – Response 4 on pages 18649-18650 and Virginia Ozone iSIP approval Section (II)(B)(3) – Response 4 on page 17048. 

11 Guidance on Infrastructure State Implementation Plan (SIP) Elements under Clean Air Act Sections 110(a)(1) 

and 110(a)(2), page 18, U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards; 

September 13, 2013. 
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not limited to rulemaking, permit amendment or SIP revision, or a combination thereof. 

This approach is supported by EPA’s long-standing position regarding i-SIPs, which is

that “they are general planning SIPs to ensure that the state has adequate resources and 

authority to implement a NAAQS in general throughout the state and not detailed 

attainment and maintenance plans for each individual area of the state.”12 DEP’s i-SIPs 

demonstrate that Pennsylvania has adequate resources and authority.

11. COMMENT: Pennsylvania’s draft SO2 i-SIP must include emission limitations and 

should use modeling to show that the emission limitations (source-specific one-hour SO2

emission limits) show no exceedances of the SO2 NAAQS when modeled. (2)

RESPONSE: See Note 2 and the responses to Comments 6 through 10, above, for 

DEP’s position on the inclusion of emission limitations in i-SIPs. DEP will evaluate all 

available tools, including modeling data and analysis, through mechanisms that may 

include but are not limited to rulemaking, permit amendment or SIP revision, or a 

combination thereof, as necessary and appropriate, to meet CAA requirements for the 

SO2 NAAQS.

12. COMMENT: Pennsylvania’s draft SO2 I-SIP must include enforceable SO2 emission 

limits with a one-hour averaging period that apply at all times. (2)

RESPONSE: See Note 2 and the responses to Comments 6 through 10, above, for 

DEP’s position on the inclusion of emission limitations in i-SIPs. DEP will evaluate 

requirements relating to emission limitations, including averaging periods, through 

mechanisms that may include but are not limited to rulemaking, permit amendment or 

SIP revision, or a combination thereof, as necessary and appropriate, to meet CAA 

requirements for the SO2 NAAQS.

13. COMMENT: Pennsylvania’s draft SO2 I-SIP must require monitoring of SO2 emission 

limits on a continuous basis using a continuous emission monitor system or systems. (2)

RESPONSE: See Note 2 and the responses to Comments 6 through 10, above. DEP 

will evaluate monitoring requirements through mechanisms that may include but are not 

limited to rulemaking, permit amendment or SIP revision, or a combination thereof, as 

necessary and appropriate, to meet CAA requirements for the SO2 NAAQS.

14. COMMENT: PaDEQ must establish enforceable emission limits at major sources and 

must amend Pennsylvania’s draft SO2 I-SIP to include those limits, to ensure that large 

sources of SO2 cannot cause exceedances of the one-hour SO2 NAAQS. Commentator 

made the same comment relating to the draft ozone I-SIP, relating to emission limits for 

ozone precursor pollutants. (2)

 

12. See footnote 4. 
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RESPONSE: See Note 2 and the responses to Comments 6 through 10, above, for 

DEP’s position on the inclusion of emission limitations in i-SIPs. DEP will evaluate 

requirements relating to emission limitations at major sources through mechanisms that 

may include but are not limited to rulemaking, permit amendment or SIP revision, or a 

combination thereof, as necessary and appropriate, to meet CAA requirements for the 

SO2 NAAQS.

15. COMMENT: Pennsylvania’s draft Ozone I-SIP fails to include enforceable emission 

limitations needed to address significant monitored violations of the primary ozone 

NAAQS. (2)

RESPONSE: See Note 2 and the responses to Comments 6 through 10, above, for 

DEP’s position on the inclusion of emission limitations in i-SIPs. DEP will evaluate all 

available tools, including monitoring data, through mechanisms that may include but are 

not limited to rulemaking, permit amendment or SIP revision, or a combination thereof, 

as necessary and appropriate, to meet CAA requirements for the ozone NAAQS.

16. COMMENT: Monitoring data demonstrates that at least one county in Pennsylvania is 

exceeding the 2008 Ozone NAAQS. Pennsylvania’s draft Ozone I-SIP should be revised 

to address these exceedances and ensure attainment and maintenance of the 2008 Ozone 

NAAQS. (2)

RESPONSE: EPA has stated that, “States must develop SIPs based on the information 

they had during the SIP development process and data that becomes available after that 

process is completed cannot undermine the reasonable assumptions that were made by 

the state based on the information it had available as it developed the plan.”13 

Additionally, the CAA has provisions to address changes in air quality over time, 

including ‘provisions providing for redesignation in Section 107(d) of the CAA and 

provisions in Section 110(k)(5) of the CAA allowing EPA to call on the state to revise its 

SIP, as appropriate.”14 If EPA chooses to redesignate areas currently designated as 

attainment as nonattainment based on later years’ data, DEP would address 

nonattainment area SIP requirements, as necessary, for those areas at the time revised 

designations would become final. See Note 2 and the responses to Comments 6 through

10, above.

17. COMMENT: Adding control devices and emission limitations on electric generating 

units are a cost effective option to reduce NOX and attain and maintain the 2008 Ozone 

NAAQS. (2)

RESPONSE: See Note 2 and the responses to Comments 6 through 10, above, for 

DEP’s position on the inclusion of emission limitations in i-SIPs. DEP will address 

 

13. See Delaware Ozone i-SIP approval Section (III)(C) – Response 1 on page 18647 and Virginia Ozone i-SIP 

approval Section (II)(B) – Response 1 on pages 17045-17046.

14. See footnote 13. 
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control strategies, cost-effectiveness and emission limitations through mechanisms that 

may include but are not limited to rulemaking, permit amendment or SIP revision, or a 

combination thereof, as necessary and appropriate, to meet CAA requirements for the 

ozone NAAQS.

18. COMMENT: Pennsylvania should use the Ozone I-SIP process to address current 

ozone exceedances in Dauphin, Erie, Indiana, Mercer and York counties and prevent 

these counties from being redesignated as nonattainment for the 2008 Ozone NAAQS, or 

designated as nonattainment for the forthcoming Ozone NAAQS (referencing the current 

EPA review of the Ozone NAAQS, initiated in September 2008 – 

http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_2008_pd.html), by adding 

appropriate enforceable emission limits on NOX sources. (2)

RESPONSE: See the responses to Comments 6 through 10 for DEP’s position on the 

inclusion of emission limitations in I-SIPs. See Comment 16 for DEP’s position on using 

the i-SIP to address NAAQS exceedances.

19. COMMENT: Pennsylvania’s draft NO2 I-SIP fails to include enforceable one-hour NO2

emission limitations to ensure attainment and maintenance of the primary NO2 NAAQS. 

(2)

RESPONSE: See Note 2 and the responses to Comments 6 through 10, above, for 

DEP’s position on the inclusion of emission limitations in i-SIPs.

20. COMMENT: Pennsylvania’s draft PM2.5 I-SIP fails to include enforceable PM2.5

emission limitations, with annual averaging periods, that apply at all times, to ensure 

attainment and maintenance of the PM2.5 NAAQS. (2)

RESPONSE: See Note 2 and Responses to Comments 6 through 10, above, for DEP’s 

position on the inclusion of emission limitations in i-SIPs. DEP will evaluate 

requirements relating to emission limitations, including averaging periods, through 

mechanisms that may include but are not limited to rulemaking, permit amendment or 

SIP revision, or a combination thereof, as necessary and appropriate, to meet CAA 

requirements for the PM2.5 NAAQS.

21. COMMENT: Pennsylvania’s draft PM2.5 I-SIP must require monitoring of PM2.5

emission limits on a continuous basis using a continuous emission monitor system or 

systems. (2)

RESPONSE: DEP will evaluate monitoring requirements through mechanisms that may 

include but are not limited to rulemaking, permit amendment or SIP revision, or a 
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combination thereof, as necessary and appropriate, to meet CAA requirements for the 

PM2.5 NAAQS. See Note 2 and the responses to Comments 6 through 10, above.

22. COMMENT: The statutory and regulatory sections that PaDEQ incorporated into its 

draft I-SIPs (2008 Ozone, 2010 NOX, 2010 SOX, and 2012 PM2.5) are insufficient to 

ensure compliance with the 2010 NO2, 2010 SO2, 2008 ozone, and 2012 PM2.5 NAAQS.

None of the rules and regulations cited in Pennsylvania's draft I-SIPs include 

appropriate emission limits for the 2010 NO2, 2010 SO2, 2008 ozone, and 2012 PM2.5

NAAQS, as shown by modeling and monitoring data. Pennsylvania must revise its I-SIP 

to include enforceable emission limits that address the exceedances shown by the monitor 

data and that otherwise address the 2010 NO2, 2010 SO2, 2008 Ozone, and 2012 PM2.5

NAAQS, and it must update its emission regulations to ensure that proper mass 

limitations and short term averaging periods are imposed on large sources of pollution. 

(2)

RESPONSE: The i-SIP process is not the appropriate tool to address potential 

regulatory revisions for the purposes suggested by the commentator. See Note 2 and 

Responses to Comments 6 through 10, above, for DEP’s position on including emission 

limitations in the i-SIP. DEP will address mass limitations and averaging periods through 

mechanisms that may include but are not limited to rulemaking, permit amendment or 

SIP revision, or a combination thereof, as necessary and appropriate, to meet CAA 

requirements for the NAAQS cited in the comment.

23. COMMENT: Pennsylvania’s draft I-SIPs (2008 Ozone, 2010 NOX, 2010 SOX, and 

2012 PM2.5) fail to address sources significantly contributing to nonattainment or 

interference with maintenance of the NAAQS in downwind states [relating to CAA 

Section 110(a)(2)(D)(i)(I)]. (2)

RESPONSE: DEP has not addressed Section 110(a)(2)(D)(i)(I) in the final i-SIPs 

submitted to EPA for the 2008 Ozone, 2010 NOX, 2010 SOX, and 2012 PM2.5 NAAQS. 

DEP intends to submit a separate SIP revision in the future to address 

Section 110(a)(2)(D)(i)(I).

24. COMMENT: Pennsylvania’s draft I-SIPs (2008 Ozone, 2010 NOX, 2010 SOX, and 

2012 PM2.5) fail to protect visibility in other states by relying on Pennsylvania’s Regional 

Haze SIP [relating to CAA Section 110(a)(2)(D)(i)(II)]. (2)

RESPONSE: EPA issued a limited disapproval and limited approval of Pennsylvania’s 

Regional Haze SIP revision on June 7, 2012, and April 30, 2014, respectively 

(77 FR 33642 and 79 FR 24340). The limited disapproval resulted from Pennsylvania’s 

reliance on the Clean Air Interstate Rule (CAIR) to address regional emission transport. 

The limited disapproval included a Regional Haze Federal Implementation Plan (FIP) for 

Pennsylvania, which replaced reliance on CAIR with reliance on the Cross-State Air 
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Pollution Rule (CSAPR). The U.S. Court of Appeals vacated CSAPR in August 2012 

and ordered EPA to continue administering CAIR. EME Homer City Generation L.P. v 

EPA, 696 F.3d 7 (D.C. Cir. 2012), cert. granted 133 S.Ct. 2857 (2013). The Supreme 

Court of the United States on April 29, 2014, reversed the Court of Appeals’ judgment 

and remanded the case for further proceedings. Environmental Protection Agency v. 

EME Homer City Generation, L.P., 134 S. Ct. 1584 (2014). The commentator is 

incorrect that the April 2014 court decision reinstated CSAPR. Pennsylvania’s Regional 

Haze SIP, along with Pennsylvania’s SIP provisions to implement CAIR, adequately 

prevents sources in Pennsylvania from interfering with measures adopted by other states 

to protect visibility. If CSAPR is reinstated or if a new interstate transport rule is 

promulgated, DEP will address any new requirements under it, as necessary and 

appropriate.