Response to Comments on Proposed 

Massachusetts Certifications of Infrastructure State Implementation 

Plans for the 2008 Ozone NAAQS, 2010 N02 NAAQS, and 

2010 S02 NAAQS 

On August 3, 2013, the Massachusetts Department of Environmental Protection (MassDEP) 

issued a notice of public hearing on three proposed Certifications in which MassDEP concludes 

that the existing Massachusetts State Implementation Plan (SIP) adequately meets the basic 

("infrastructure") requirements of 42 U.S.C. § 7410(a)(l) and (2), Sections l lO(a)(l) and (2) of 

the Clean Air Act (CAA), with respect to the: 

• National Ambient Air Quality Standards (NAAQS) for ozone promulgated by the U.S. 

Environmental Protection Agency (EPA) on March 12, 2008 (the 2008 ozone NAAQS); 

• NAAQS for nitrogen dioxide (N02) promulgated by EPA on January 22, 2010 (the 2010 

N02 NAAQS); and 

• NAAQS for sulfur dioxide promulgated by EPA on June 2, 2010 (the 2010 S02 

NAAQS). 

MassDEP held a public hearing on the proposed Infrastructure SIP Certifications (I-SIPs) on 

September 6, 2013 and accepted comments on the proposals through September 16, 2013. On 

September 13 , 2013, EPA issued its "Guidance on Infrastructure State Implementation Plan 

Elements under Clean Air Act Sections J JO(a)(l) and l JO(a)(2) " (EPA's Guidance). 

The following parties submitted comments on the proposed I-SIP Certifications: 

• EPA Region 1 commented on the proposed Ozone, N02 and S02 1-SIPs; 

• The Sierra Club commented on the proposed Ozone and S02 I-SIPs. 

EPA Comments1 

EPA submitted the fo llowing comments concerning the Ozone I-SIP, the N02 I-SIP and the S02 

I-SIP. 

1. Comment: Prevention of Significant Deterioration (PSD): Since Massachusetts does not 

have a SIP-approved PSD program, the PSD elements in the proposed Infrastructure SIPs (1-

SIPs) are not approvable (e.g., section l 10(a)(2) sub-elements (C), (D)(i)(ll), and (J) as they 

relate to the state's PSD program, as well as (D)(ii), which relates to interstate and international 

pollution abatement). However, a Federal Implementation Plan (FIP) is already in place to 

address this issue. Therefore, no further action is necessary at this time. 

Response: MassDEP agrees that no further action is required. 

1 EPA's comments are reproduced verbatim. 
2. Comment: 11 O(a)(2)(A) Emission limits and other control measures: The proposed I-SIPs 

state that the Commonwealth will submit a SIP revision including a new definition of the term 

"National Ambient Air Quality Standards (NAAQS)." This SIP revision will need to be 

submitted before EPA can approve the infrastructure SIPs. 

Response: MassDEP's regulation 310 CMR 7.00, Definitions, uses the term National Ambient 

Air Quality Standards (NAAQS) but does not define the term or indicate to which version of the 

standards the regulations refer. In 2012, EPA commented on MassDEP' s I-SIPs for the 1997 

and 2006 fine particulate matter NAAQS stating that MassDEP must add a definition ofNAAQS 

to its regulations and the definition must include a calendar date to make clear to which NAAQS 

version MassDEP's regulations refer. 

To address the 2012 EPA comment, in May 2013 , MassDEP proposed a revision to 310 CMR 

7.00 to include a definition of the term "NAAQS" that includes a calendar date. This revision 

will apply to all of the pollutants for which EPA sets NAAQS. MassDEP has held hearings on 

the proposed revision and intends to promulgate the revision to 310 CMR 7.00 as soon as 

possible and submit it to EPA for inclusion in the Massachusetts SIP. 

3. Comment: 11 O(a)(2)(B) Ambient Air quality monitoring/data system: Massachusetts' 

proposed I-SIPs includes a citation to 40 CFR 52.370, regarding a SIP-approved air quality 

monitoring plan. We believe the citation should instead be to 40 CFR 52.11 20( c )(36). 

Response: MassDEP has corrected the citation in each of the final I-SIPs. 

4. Comment: 11 O(a)(2)(C) Enforcement: The proposed I-SIPs reference three state statutes, as 

well as regulation 310 CMR 5. 00 for this sub-element. The statutes and regulations that 

Massachusetts is relying on to meet the enforcement requirement should be submitted for 

incorporation into the SIP. 

Response: MassDEP submitted, with the I-SIPs, copies of the following statutes that 

demonstrate that it has adequate enforcement authority: 

• M.G.L. c. 111 , s. 142A- O, Pollution Control Laws, as amended in 2009 and 2010. 

• M.G.L. c. 111 , s. 2C. Pollution violations; orders of department of environmental 

protection. 

• M.G.L. c. 21A, s. 16. Civil Administrative Penalties. 

MassDEP is not requesting that these statutes be incorporated in the Massachusetts SIP. In 

conversations with EPA Region 1 staff subsequent to EPA' s submitting this comment, Region 1 

staff advised that a copy of the statutes should be submitted with the final I-SIPs but that 

incorporation of the statutes into the SIPs is not required. 

Furthermore, EPA' s Guidance concerning this SIP element states (p. 24) that "new" provisions 

should be submitted for incorporation, but does not require submission of existing statutes and 

regulations for incorporation. These MassDEP enforcement-related statutes and regulations are 

not new and have been a part of MassDEP's air quality program for many years. 

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5. Comment: 11 O(a)(2)(D)(ii) Interstate pollution abatement and international air pollution: 

Under this sub-element, as noted on pages 38 and 39 ofEPA's I-SIP guidance, we recommend 

that Massachusetts include the following two statements in each I-SIP: 

"No source or sources within Massachusetts are the subject of an active finding under 

section 126 of the Clean Air Act with respect to the [2008 ozone, 2010 S02, or 2010 

N02] standard." 

"There are no final findings under section 115 of the Clean Air Act against Massachusetts 

with respect to the [2008 ozone, 2010 S02, or 2010 N02] standard." 

Response: MassDEP inserted the two recommended statements into each of the final I-SIPs. 

6. Comment: 11 O(a)(2)(H) Future SIP revisions: The proposed I-SIPs list the Massachusetts 

General Statute M.G.L. c 111 , s. 142A-N that allows for future SIP revisions. As noted on page 

51 ofEPA's Guidance: 

"To demonstrate that the requirements under (H) are met, the best practice for an air agency 

submitting an infrastructure SIP would be to submit, for inclusion into the SIP (if not already 

part of the SIP), the statutory or regulatory provisions that provide the air agency or official 

with the authority to perform the following actions along with a narrative explanation of how 

they meet the requirements of this element: (1) revise its section 110 plan from time to time as 

may be necessary to take into account revisions of such primary or secondary NAAQS or the 

availability of improved or more expeditious methods of attaining such standards; and (2) 

revise the plan in the event the Administrator finds the plan to be substantially inadequate to 

attain the NAAQS or otherwise meet all applicable CAA requirements." p. 51 , EJ;>A's 

Guidance. 

Response: MassDEP notes that EPA's Guidance, at page 51, also states the following: 

"If an air agency chooses not to include the relevant statute or regulation in its SIP, then the 

air agency should provide a reference or citation to the authority provisions, along with a 

narrative explanation of how the provisions meet the requirements of this element, as well as 

a copy of the relevant authority to accompany the SIP as required by 40 CFR 51.231 ." 

As noted in the response to comment #4, MassDEP submitted a copy of. M.G.L. c. 111, s. 

142A- O, as amended in 2009 and 2010, with the I-SIP. The specific sections cited below 

demonstrate that MassDEP has authority to amend the Massachusetts SIP as needed. 

Section 142A: "The department of environmental protection, referred to in this section and in 

sections one hundred and forty-two B through one hundred and forty-two M, inclusive, as the 

department may from time to time adopt regulations, pursuant to this section and sections one 

hundred and forty-two B through one hundred and forty-two M, inclusive, to prevent pollution or 

contamination of the atmosphere." 

Section 142D: "From time to time the department shall review the ambient air quality standards 

and plan for implementation, maintenance and attainment of such standards adopted pursuant to 

this section and, after public hearings, shall amend such standards and implementation plan so as 

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to minimize the economic cost of such standards and plan for implementation, provided, 

however, that such standards shall not be less than the minimum federal standards." 

7. Comment: 11 O(a)(2)(J) Public Notification: The proposed 1-SIPs reference a statutory 

requirement that Mass DEP provide notice and public comment and hearing prior to adoption of 

regulations. However, this sub-element deals with the public notification of poor air quality. 

(See page 54 of EPA's I-SIP guidance.) Therefore, EPA recommends that the DEP instead 

reference Massachusetts' participation in AIRNOW and its activities to regularly notify the 

public of exceedances of the air quality standards (e.g., air quality web site, alerts, press releases, 

etc.) 

Response: MassDEP has revised its discussion of this requirement to reference Massachusetts' 

participation in EPA's AIRNOW program and MassDEP's daily air quality forecasts and alerts 

and air quality web site. 

8. Comment: 11 O(a)(2)(J) Consultation with Government Officials: For this sub-element, the 

proposed 1-SIPs list three Massachusetts General Statutes (M.G.L. c 21a, c. 111 and c. 30A) and 

an Executive Order and do not list any SIP-approved regulations that require consultation. EPA 

recommends that D EP consider referencing Section VII of the Massachusetts 1972 SIP which 

does require the DEP to consult with other government officials in its regulatory actions. Section 

II of the Massachusetts 1972 SIP may also be relevant. Alternatively, Massachusetts could 

submit the appropriate state statutes for incorporation into the SIP. Furthermore, as noted on 

page 53 ofEPA's Guidance: 

"Under the requirements of 40 CFR 51.2402

, the SIP would need to identify 

organizations that will participate in developing, implementing and enforcing the plan 

and the responsibilities of such organizations. The plan should also include any related 

agreements or memoranda of understanding among the organizations." 

Response: The final 1-SIPs references the 1972 Massachusetts Plan for the Implementation, 

Maintenance, and Enforcement of National Primary and Secondary Ambient Air Quality 

Standards (the 1972 SIP), which documents the requirements for MassDEP to consult with other 

government officials. Section VII of the 1972 SIP, entitled "Intergovernmental and InterAgency Cooperation " provides that Massachusetts will cooperate with adjoining and other states 

to address interstate air quality control, citing NESCAUM (the New England Staff for 

Coordinating Air Use Management)3 as an example of interstate cooperation. Since the 

submission of the 1972 SIP, MassDEP has maintained active membership in NESCAUM, which 

has continued to be a forum for consultation with air program officials of other states in the 

northeast. In addition , interstate consultation became a federal statutory requirement through 

the creation of the Ozone Transport Region (OTR) pursuant to the 1990 Clean Air Act 

2 40 CFR § 51.240 - General plan requirements. Each State implementation plan must identify organizations, by 

official title, that will participate in developing, implementing, and enforcing the plan and the responsibilities of 

such organizations. The plan shall include any related agreements or memoranda of understanding among the 

organizations. 3 NESCAUM is now the Northeast States for Coordinated Air Use Management and includes the states of New 

York and New Jersey. 

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Amendments. Massachusetts is within the OTR and actively participates in the Ozone Transport 

Commission, which coordinates interstate air quality planning among the OTR states. 

Section VII ( c) of the 1972 SIP also discusses the existence of six air quality control regions 

within Massachusetts, and the role of the Bureau of Air Quality Control (at that time within the 

Department of Public Health) in administering, overseeing and coordinating inter-district 

cooperation. The role of municipally-operated air pollution control programs within the six air 

quality control regions in implementing the air program is discussed in detail in Section VII, 

Resources. 

Section VII ( d) of the 1972 SIP lists the state statues that require the cooperation and/or 

assistance in the control of air pollution by other state agencies. 

Section II of the 1972 SIP, "Legal Authority" lists the statutes that provide MassDEP with the 

legal authority to carry out the plan. The statutes cited also provide that cities or towns may 

apply to MassDEP to form air pollution control districts. The powers, duties, and rights of 

MassDEP in the exercise of air pollution control in such districts are spelled out in the statutes 

referenced in the I-SIP. 

MassDEP submitted to EPA on September 1, 1977, a Memorandum of Understanding signed by 

the Massachusetts air and transportation agencies related to Section 109(a)(2)(J) requirements 

concerning the integration of air quality considerations into the transportation planning and 

development process. 

As noted in the proposed I-SIPs, Executive Order No. 145, adopted in 1978, requires state 

agencies, including MassDEP, to provide notice to the Local Government Advisory Committee 

soliciting input on the impact of proposed regulations on local government. MassDEP submitted 

a copy of Executive Order No. 145 with the final I-SIPs. 

The final I-SIPs note that MassDEP has the responsibility for overall coordination of SIP 

planning and is the lead compliance and enforcement agency related to all matters incorporated 

into SIPs. These responsibilities were outlined in a July 9, 1993 letter from Governor William F. 

Weld to EPA Region 1. The Jetter designates MassDEP as the lead agency for stationary and 

area sources and the lead for programs related to motor vehicle fuels, vehicle inspection and 

maintenance, and ridesharing. The letter designates the Executive Office of Transportation and 

Construction (EOTC)4 

as the lead agency in SIP planning for all transportation initiatives in 

consultation with Metropolitan Planning Organizations, which include representation of locallyelected officials through membership on transit authority advisory boards and regional planning 

commissions. The letter states that MassDEP must approve all actions incorporated into the SIP. 

For enforcement of transportation initiatives, MassDEP may rely on other state and local 

agencies including the State Police, the Registry of Motor Vehicles, the Massachusetts Highway 

Department, and local law enforcement and public health officials. 

Massachusetts does not have a SIP-approved state transportation conformity rule. However, 

consistent with section 176 of the CAA and 40 CRF 93 relative to conformity determinations, 

including provisions for consultation as required by section l 76(c)( 4) and 40 CFR 93.105, 

4 The EOTC is now the Massachusetts Department of Transportation. 

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MassDEP and the Massachusetts Department of Transportation consult with local, regional, and 

federal agencies to ensure that transportation plans, programs, projects, and federal actions are 

consistent with the SIP. 

9. Comment: 110(a)(2)(J) Visibility Protection: Under this sub-element, the proposed I-SIPs 

refer back to the earlier Massachusetts chart entry for 11 O(a)(2)(C), but there is no discussion on 

visibility under element (C). However, as noted on page 55 of EPA's Guidance: 

"The EPA believes that there are no new visibility protection requirements under part C 

as a result of a revised NAAQS (National Ambient Air Quality Standard). Therefore, 

there are no newly applicable visibility protection obligations pursuant to Element J after 

the promulgation of a new or revised NAAQS. Air agencies do not need to address the 

visibility sub-element of Element Jin an infrastructure SIP submission." 

Therefore, we recommend that under the (J) visibility protection sub-element, DEP delete the 

current reference to back to (C) and instead state that this element does not need to be addressed 

pursuant to EPA's Guidance. 

Response: MassDEP has revised this section as EPA recommends. 

10. Comment: 110( a)(2)(M) Consultation and Participation by affected local entities: The 

proposed I-SIPs list Massachusetts General Statute M.G.L. c. 30A and an Executive Order and 

do not list any SIP-approved regulations that require consultation. EPA recommends that DEP 

consider referencing Section VII of the Massachusetts 1972 SIP which does require the DEP to 

consult with other government officials in its regulatory actions. Section II of the Massachusetts 

1972 SIP may also be relevant. Alternatively, Massachusetts could submit the appropriate state 

statutes for incorporation into the SIP. 

Response: The final I-SIPs include references to the contents of the 1972 SIP that relate to this 

element. As noted in the response to comment #8 (110( a)(2)(J) - Consultation with Government 

Officials), the 1972 SIP includes provisions relating to consultation with local political 

subdivisions. Section VII ( c) of the 1972 SIP discusses six air quality control regions within 

Massachusetts, and the role of the Bureau of Air Quality Control (at that time within the 

Department of Public Health) in administering, overseeing and coordinating inter-district 

cooperation. The role of municipally-operated air pollution control programs within the six air 

quality control regions in implementing the air program is discussed in detail in Section VII, 

Resources. 

Section VII ( d) of the 1972 SIP lists the state statues that require the cooperation and/or 

assistance in the control of air pollution by other state agencies. 

Section II of the 1972 SIP, "Legal Authority" lists the statutes that provide MassDEP with the 

legal authority to carry out the plan. The statutes cited also provide that cities or towns may 

apply to MassDEP to form air pollution control districts. The powers, duties, and rights of the 

department in the exercise of air pollution control in such districts are spelled out in the statutes 

referenced in the I-SIP. 

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• 

As noted in the Response to comment #8, MassDEP submitted with the final I-SIPs a copy of 

Executive Order No. 145, which requires state agencies to provide notice to the Local 

Government Advisory Committee soliciting input on the impact of proposed regulations on local 

governments. 

The final I-SIPs also include discussion of MassDEP's policy related to consultation with local 

political subdivisions through the Massachusetts SIP Steering Committee, which was created 

pursuant to the 1990 Clean Air Amendments. The following constituencies are represented on 

the SIP Steering Committee: local and regional governmental entities, business and industry, 

and environmental groups and academia. The Committee provides a forum for consultation and 

participation by affected local entities in the development of SIPs and air quality regulations. 

Additionally, as a matter of policy when adopting air regulations, MassDEP conducts 

stakeholder outreach, including meetings to elicit stakeholder feedback, before proposing 

regulations for formal public review and comment. Local entities affected by regulations or SIP 

revisions are provided opportunities to consult with MassDEP through the stakeholder outreach 

process. 

M.G.L. c. 30A, Administrative Procedures, provides that MassDEP must provide public notice in 

accordance with Chapter 30A prior to the adoption, amendment, or repeal of any regulation. 

Leaders of political subdivisions have the opportunity to review such notices and to participate in 

the public process required by Chapter 30A. MassDEP also must comply with EPA 

requirements related to public notice of SIP revisions, which puts local political subdivisions on 

notice of changes that may affect them. 

Sierra Club Comments5 

Sierra Club comments concerning the Ozone I-SIP 

1. Comment: The regulations cited in the proposed infrastructure SIP fail to ensure adequate 

compliance with the 2008 ozone NAAQS. 

Response: The Massachusetts SIP includes multiple regulations to control ozone precursors, 

which are cited in the I-SIP. These regulations ensure compliance with the 2008 ozone NAAQS 

as demonstrated by Massachusetts' state-wide attainment designation, except for Duke's County, 

which has been designated as a marginal nonattainment area. 77 FR 30088, May 21 , 2012. The 

ozone concentrations in Duke's County leading to a marginal nonattainment designation are 

attributable to transported pollution from states that are upwind of Massachusetts. 

2. Comment: The Ozone I-SIP must include provisions to ensure that ozone emissions will not 

cause or significantly contribute to nonattainment or interfere with maintenance of the Ozone 

NAAQS in another state. 

5 Sierra Club's comments are summarized in this document. 

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Response: To address the contribution of upwind states to ozone in downwind states, EPA 

promulgated the Cross-State Air Pollution Rule (CSAPR) in 2011 to replace EPA' s 2005 Clean 

Air Int~rstate Rule (CAIR). In its CSAPR transport analysis, EPA found that Massachusetts 

does not significantly contribute to ozone nonattainment or interfere with maintenance in any 

other state. 76 FR 48213 , August 8, 2011. EPA's CSAPR analysis is the latest contribution 

analysis available. Note that in August 2012, the D.C. Circuit Court of Appeals vacated CSAPR 

and left CAIR in place, but on April 29, 20 14, the Supreme Court of the United States upheld 

CSAPR and remanded the case back to the D.C. Circuit Court of Appeals. MassDEP continues 

to implement the MassCAIR program. Once EPA decides how it intends to proceed with 

CSAPR, MassDEP will submit a separate transport SIP to EPA to address this issue if necessary, 

once EPA has provided updated guidance. 

3. Comment: The Ozone I-SIP should include measures to address significant sources of ozone 

precursors, such as electric generating units. 

Response: The Massachusetts Ozone SIP includes multiple regulations to control ozone 

precursors from stationary sources, including electric generating units. These regulations are 

cited in the I-SIP (for example, see page 7). 

4. Comment: The Ozone I-SIP should include measures to address leaks from natural gas 

distribution pipelines. Methane is a major source of ozone precursors. Leaking gas pipelines 

create risks of explosions and increase costs to consumers. 

Response: The Massachusetts Ozone SIP includes multiple regulations to reduce emissions of 

volatile organic compounds (VOCs), which contribute to the formation of ozone. 310 CMR 

7.00, Definitions, lists those compounds, including methane, that are excluded from the 

definition of VOC. Methane is not a VOC so is not regulated as part of the Ozone SIP. 

Sierra Club comments concerning the Ozone I-SIP and the S02 I-SIP 

5. Comment: The proposed Ozone I-SIP and the proposed S02 I-SIP impermissibly fail to 

incorporate the respective revised NAAQS. 

Response: As noted in MassDEP's Response to EPA's Comment #1 above, MassDEP intends 

to promulgate a revision to 310 CMR 7.00, Definitions, to add a definition ofNAAQS that 

addresses this issue. 

6. Comment: The Ozone I-SIP and S02 I-SIP must protect visibility in other states and cannot 

rely on a Regional Haze Plan that has not been approved by EPA. 

Response: EPA approved the Massachusetts Regional Haze SIP effective October 21 , 2013. 78 

Federal Register 57487, September 19, 2013. 

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Sierra Club comments concerning the S02 I-SIP 

7. Comment: The Clean Air Act, EPA's regulations and EPA's interpretations thereof, and 

court opinions, require that 1-SIPs must have emission limits adequate to prevent AAQS 

violations in areas not designated nonattainment. 

Response: As stated in EPA' s Guidance, pursuant to CAA Section 110( a)(2) states are required 

to develop and maintain an air quality management program that meets various basic structural 

requirements including "enforceable emission limitations." EPA has not interpreted the 

requirement for "enforceable emission limitations" to include single-source specific emission 

limitations in an infrastructure SIP. Rather, a state must demonstrate that it has in place a 

regulatory framework that requires the imposition of enforceable emission limitations to insure 

the NAAQS can be attained and maintained. Consistent with EPA's Guidance, MassDEP's S02 

I-SIP demonstrates that it has the regulatory framework allowing it to impose and enforce such 

emission limits. (See Response to Comment # 10 below.) 

8. Comment: The Sierra Club encourages MassDEP to expeditiously complete its 310 

CMR7.02(7) compliance demonstration processes for Brayton Point and Mount Tom and to 

impose appropriate modeling-informed short-term emission limits for both plants. 

Response: MassDEP is working to complete its 310 CMR 7.02(7) review process related to 

S02 emissions and emission limits for these two facilities as quickly as possible. 

9. Comment: MassDEP should coordinate the timing of finalizing the S02 I-SIP so that it 

incorporates the modeling-informed short-term emissions limits for Brayton Point and Mount 

Tom into the SIP. 

Response: As noted above in its Response to Sierra Club comment #7, EPA has not interpreted 

the requirement for "enforceable emission limitations" to include single-source specific emission 

limitations in an infrastructure SIP. Rather, a state must demonstrate that it has in place a 

regulatory framework that requires the imposition of enforceable emission limitations to insure 

the NAAQS can be attained and maintained. Consistent with EPA's Guidance, MassDEP's S02 

I-SIP demonstrates that it has the regulatory framework allowing it to impose and enforce such 

emission limits. 

10. Comment: Should MassDEP decline to delay finalization of the I-SIP, MassDEP should 

include in the SIP a provision clarifying the requirement of enforceable NAAQS-protective 

emission limits for sources calculated to cause exceedances of the standard. 

Response: MassDEP regulations that are already part of the Massachusetts SIP include 

provisions to ensure that facilities do not cause NAAQS violations. 310 CMR 7.02, Plan 

Approval and Emission Limitations, provides procedures and standards for issuing approvals in 

Massachusetts and establishing emission limitations and conditions for facilities and emission 

units. 310 CMR 7.02 generally requires a plan approval (permit) prior to any construction, 

substantial reconstruction, alteration, or subsequent operation of a facility that may emit 

contaminants to the ambient air. It also allows MassDEP to address a condition of air pollution 

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caused by a facility. The following provisions of 310 CMR 7.02 address the issue ofNAAQS 

compliance: 

310 CMR 7.02(3)U), General Requirements for Plan Approval, provides that MassDEP will 

issue a plan approval for a stationary source only if the emissions from a facility do not result in 

air quality exceeding either the Massachusetts or National Ambient Air Quality Standards. 

310 CMR 7.02(5)(a) 10, Comprehensive Plan Application, provides that facilities that do not 

trigger the general approval requirements of 310 CMR 7.02(3)U), are required to apply for an 

approval if MassDEP determines that the facility has the potential to cause or contribute to a 

condition of air pollution. 

310 CMR 7.02(7), Mitigation of Air Pollution, provides that when MassDEP determines that a 

facility has the likelihood of causing or contributing to a condition of air pollution, MassDEP 

may require that the facility submit information to allow MassDEP to determine the adequacy of 

existing air pollution control technology at a facility to prevent a condition of air pollution. 

These provisions of 310 CMR 7. 02 ensure that stationary emissions sources will be subject to 

enforceable NAAQS-protective emissions limits. MassDEP's current re-assessment of S02 

emissions from the Brayton Point and Mt Tom facilities exemplify the adequacy of MassDEP's 

existing regulatory infrastructure. Pursuant to 310 CMR 7.02, MassDEP is conducting a 

comprehensive review of these facility emissions and measures to ensure NAAQS compliance. 

11. Comment: The S02 I-SIP must include provisions to ensure that S02 emissions will not 

cause or significantly contribute to nonattainment or interfere with maintenance of the S02 

NAAQS in another state. 

Response: According to EPA's Guidance, an I-SIP must demonstrate that a regulatory 

framework is in place to ensure that emissions within the state do not interfere with downwind 

maintenance and attainment. As noted in the response to comment #7, MassDEP's S02 I-SIP 

demonstrates that it has the regulatory framework to ensure S02 emissions will not cause or 

significantly contribute to nonattainment or interfere with maintenance of the S02 NAAQS in 

another state. In addition, until EPA completes final designations for areas downwind of 

Massachusetts it is premature to address the possible contribution of Massachusetts sources to 

downwind S02 maintenance or attainment issues. 6 

6 In 2011 , New Hampshire recommended to EPA that a portion of central NH be designated as an S02 

nonattainment area. New Hampshire's technical support for its nonattainment recommendation does not reflect any 

contribution to nonattainment from Massachusetts sources. 

http://des. nh.gov/organization/divisions/air/do/sip/documents/so2-nh-designation-request.pdf 

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