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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 1 

July 19, 2012 

Marc Cone 

5 POST OFFICE SQUARE SUITE 100 

BOSTON MA 02109-3912 

Bureau of Air Quality Control 

Department of Environmental Protection 

17 State House Station 

Augusta, ME 04333 

Dear Mr. Cone: 

Thank you for the opportunity to review the Maine Department of Environmental 

Protection's (DEP) proposed revisions to Chapter 100, Definitions, Chapter 115, Major 

and Minor Air Emission License Regulations and Chapter 140, Part 70 Air Emissions 

License Regulations. Our comments are attached to this letter. The revisions include 

changes to implement the current federal New Source Review (NSR) applicability test 

provisions such as the actual-to-future actual applicability test and the Plantwide 

Applicability Limits, EPA's NSR implementation requirements for Particulate Matter 

with an aerodynamic diameter less than or equal to a nominal 2.5 micrometers (PM2.s), 

federal Greenhouse Gases (GHG) permitting requirements and other changes to the state 

permitting program. Once the public comment period ends, EPA understands the DEP 

will respond to all comments made by EPA and other reviewers and submit the revised 

regulation to EPA as formal revision to its State Implementation Plan (SIP) rules. 

Again, thank you for the opportunity to review the proposed revisions to your state NSR 

permitting regulations. If you have any questions, please call Brendan McCahill at (617) 

918-1652. 

Sincerely, 

Ida E. McDonnell, Manager 

Air Permits, Toxics and Indoor Programs Unit 

Enclosure 

Toll Free • 1 888·372-7341 

Intern.it Address (URL • http '/.WW epa gov regonl 

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Enclosure 

EPA'S COMMENTS TO MAINE'S PROPOSED REVISIONS TO CHAPTER 100, 

"DEFINITIONS," CHAPTER 115, "MAJOR AND MINOR AIR EMISSION 

LICENSE REGULATIONS" AND CHAPTER 140, "PART 70 AIR EMISSIONS 

LICENSE REGULATIONS" DATED JUNE 20, 2012 

1. General Comment: EPA notes the SIP-approved nonttainment NSR plan 

requirements at 40 CFR 51.165( a)(2)(ii) states that each plan shall use the specific 

applicability provisions of paragraphs (a)(2)(ii)(A) through (F) of the section. 

Deviations from these provisions will be approved only if the state specifically 

demonstrates that the submitted provisions are more stringent than or at least as 

stringent in all respects as the corresponding provisions in paragraphs (a)(2)(ii)(A) 

through (F) of the section. The federal SIP-approved Prevention of Significant 

Deterioration (PSD) plan requirements contain a similar provision at 40 CFR 

5 l. l 66(a)(7)(iv). 

Specifically, EPA identified several revisions in the state's major NSR permitting 

applicability requirements that deviate from the federal requirements. If the DEP 

retains those revisions, the DEP will need to submit a demonstration as part of its 

SIP-approved submittal showing how the use of its revised nonattainment NSR 

and PSD program applicability procedures are as stringent in all respects as the 

corresponding federal applicability requirements. The DEP may avoid the need 

for a demonstration by incorporating the federal applicability requirements 

without revision into its regulations. 

Chapter I 00: Definitions 

2. Chapter 100.28. C02 equivalent emissions (C02e): EPA's letter to the DEP 

dated November 29, 2010 advised the DEP to add the following phrase "as it may 

be revised by EPA from time to time" or, alternatively, "as of [date]," to avoid 

confusion if Table A-1 (Global Warming Potentials) to subpart A of 40 C.F.R. 

part 89 (Mandatory Greenhouse Gas Reporting) is modified by EPA at a later 

date. EPA recommends the DEP revise this provision using one of these options. 

3. Chapter 100.82. Major Modification: 

a. 100.82 A: The DEP's provision at 100.82.A is not consistent with the federal 

definition for "Major Modification" and does not include the two part test 

provided in the federal definition. As described at 40 CFR 5 l. l 66(a)(7)(iv)(a) 

under the federal requirements for SIP-approved PSD program, a project is a 

major modification if it is physical change or change in the method of operation 

that causes two different types of emission increases: (1) a significant emissions 

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increase of a regulated pollutant and (2) a significant net emissions increase of 

that pollutant from the major stationary source. 

· In the first step, if the emission increase from the project does not exceed the 

significance level for a given pollutant, the project is not a major modification. If 

the emission increase from the project exceeds the emission threshold for a given 

pollutant, all other contemporaneous emission increases and decreases from the 

source for that pollutant are determined. If the sum of emissions from the project 

and the contemporaneous emission increases and decreases from the source 

exceed the significance level for a given pollutant, than the project is a major 

modification for that pollutant. 

The DEP's definition of "major modification" occurs if a modification results in a 

"significant emission increase." Since the DEP' s definition of significant 

emission increase means a major modification which results in any "net emission 

increase" of a regulated pollutant, the DEP's definition implements only the 

second part of the federal requirements two part test. This makes the DEP's 

definition more stringent than the federal definition. 

The following example illustrates how the DEP's definition differs from the 

federal definition. Three years ago, a major stationary source installs a device 

with a potential emission increase of 10 tons per year (tpy) of sulfur dioxide 

(S02). The source intends to install a new device with a potential increase of 35 

tpy of S02• The significant emission increase threshold for S02 is 40 tpy. Under 

the federal definition, the new device results in a significant emission increase of 

35 tpy. Since this is below 40 tpy, the new device does not result in a significant 

emission increase (the l st part of the two part test). The device is not a major 

modification. Maine's definition is based on significant net emission increase 

only, the new device results in a significant net emission increase at the major 

stationary sources of 45 tpy (35 tpy + 10 tpy). The new device is a major 

modification. 

b. Chapter 100.82.B: Chapter 100.82.B includes two additional definitions for 

"major modification." Chapter I 00.82.B (1) defines a major modification as an 

increase in the source's potential to emit by significant emissions which 

corresponds to the major stationary source thresholds in EPA's regulations. 

I 00.82.B (2) defines a major modification as an increase in actual emissions by 

significant emissions from a physical or operational change at a minor stationary 

source. Both provisions describe scenarios EPA would consider "Major 

Stationary Sources." EPA recommends the DEP remove these provisions from 

the definition of "Major modification." 

Jn addition, the DEP's regulation does not include a definition of "major 

stationary source." EPA recommends the DEP include a definition of"major 

stationary source" to its regulations that is consistent with the federal definition. 

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4. Chapter 100.92. Modification or Modified Source: Chapter 100.92.C implies 

that the replacement of a pollution control apparatus at steam electrical utility 

generators or other sources shall not be considered physical changes or changes in 

the method of operation. Federal regulations do not provide for any such 

consideration. EPA recommends the DEP remove this provision. 

5. Chapter 100.94. Net Emission Increase: 

a. EPA understands the DEP intends to implement the federal NSR requirements 

revised as of December 31, 2001. Under the federal requirements for SIPapproved PSD programs at 40 CFR 51 .166, the federal definition for "net 

emissions increase" at 40 CFR 5 l .166(b )(3) refers to a number of different 

procedures for calculating a significant emission increase for different types of 

projects (e.g., projects involving existing emission units, projects involving new 

existing units). These procedures are described in 40 CFR 5 l . I 66(a)(7)(iv). The 

DEP should include the procedures into Chapter 115. l, Applicability, of Chapter 

115, Major and Minor Source Air Emission License Regulations permitting 

regulations. The federal requirements for SIP-approved nonattairunent NSR 

programs contain similar procedures for calculating significant emission increases 

at 40 CFR 5 l . I 65(a)(2)(ii). 

b. The DEP's definition of "net emission increase" should state that an emissions 

increase or decrease of S02, particulate matter (PM) and nitrogen oxides (NOx) 

that occurs before the applicable minor source baseline date is creditable only if it 

is required to be considered in calculating the amount of maximum allowable 

increases remaining available. In other words, the increase or decrease in 

emissions was not included in determining the baseline concentration levels used 

in increment calculations. 

6. Chapter 100.154.H.: Regulated Pollutant 

Maine does not define the terms "Major New Source Review" or "Part 70 

requirements" resulting in some ambiguity of when greenhouse gases are 

considered a regulated pollutant. 

"GHGs are a regulated pollutant, except that for the purposes of 06-096 

CMR 115 and 06-096 CMR 140, they are regulated pollutants only for the 

purposes of major New Source Review and Part 70 requirements." 

Maine should clarify when greenhouse gases are considered a regulated air 

pollutant by either revising this language or defining the terms "major New 

Source Review" and "Part 70 requirements. 

7. Chapter 100.160. Significant Emissions: 

It is unclear whether the requirements in 160.A only apply between January 2, 

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2011 and July 1, 2011. To address this ambiguity Maine should add the phrase 

"In addition to subparagraph A" at the beginning of subparagraph B. 

"ln addition to the provisions in subparagraph A, beginning July 1, 2011, 

significant emissions for GHGs means any rate of emissions that would 

equal or exceed 100,000 tons per year of C02e at a new stationary source 

or an emissions . .. " 

Maine defines a major source as a source without a chapter 140 license. This 

definition causes an issue with the language in 160.A since most, if not all, 

existing part 70 sources will have a chapter 140 license. It appears the language 

contained in the second half of 160.A. is intended to outline when greenhouse gas 

emissions must be addressed when an existing major source is making a 

modification. Given the definition of "Major source" in Chapter 100, the 

language in section 100.160.A. is inconsistent with 40 CFR 51.166. Maine 

should change its definition of "Major source" to be consistent with 40 CFR 

51 .166(b )( 1 )(i), thereby ensuring modifications at existing sources properly 

address greenhouse gases. 

8. Chapter 100.161. Significant emission increase: This proposed definition 

removed paragraph D. that stated "significant" means, in reference to a net 

emission increase or potential of a source to emit a regulated pollutant that 

paragraph 100.161.A. does not list, any emission rate. Federal and SIP-approved 

PSD programs apply a 0 tpy significance level for any regulated pollutant that 

does not have a defined regulatory mass-based significance level. To meet this 

requirement, the DEP should retain paragraph D. in its regulations. 

Chapter 115: Major and Minor Source Air Emission License Regulations 

9. Chapter 115.2.U. Pollution Control Projects: The courts have vacated federal 

regulations for pollution control projects. The DEP should remove this provision. 

10. Chapter 115.2.R. Replacement of Air Pollution Control Equipment: This 

provision should clarify that air pollution control equipment shall be treated in the 

same manner as any other physical change or change in the method of operation. 

to an emission unit. 

11. Chapter 115.4.B. Process for a Plantwide Applicability Limit (PAL) at a 

Major Sources: Chapter 115.4.8(16) includes the requirements for the federal 

"Equipment replacement provision" that the courts have now vacated. The DEP 

should remove this provision in its entirety. 

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Chapter 140: Part 70 Air Emission License Regulation 

12. Chapter 140.1.C(S)(b) 

The delay in applying for an amendment to a title V license contained in this 

section is not allowed by 40 CFR part 70. An existing title V source which 

obtains a major new source review license must apply for a revision to its title V 

license pursuant to 40 CFR 70.7(e)(4). This section requires the source to obtain 

a title V license amendment prior to operating the emission units subject to the 

major new source review license. Maine must remove the new requirement in 

Chapter 140.1.C(8)(b). 

13. Chapter 140.1.D(3)(c) 

Regardless of any restrictions on emissions a source may have in a Chapter 115 

license, any source that has received a major new source review license pursuant 

to Maine's SIP approved program must have a title V license. See Clean Air Act 

§ 502(a). In addition, EPA has a policy that sources defined as major after the 

compliance date of a MACT standard will not be allowed to restrict emissions to 

avoid title V applicability. Maine should remove this section from its rule or 

clarify the fact that emission restrictions in a Chapter 115 license do not always 

remove a source from Chapter 140. 

14. Chapter 140.2.J(2)(c) 

There are two problems with this provision. First, changes requiring a major NSR 

license are not eligible for off license changes. These types of changes must be 

done using the significant modification procedures. Secondly, as stated in 

comment 12, sources currently operating under a title V permit must apply for a 

license amendment prior to operating the affected emission unit(s). To be 

consistent with 40 CFR 70.4(b)(l4), please modify the eligibility for off license 

changes. 

l 5. Chapter l 40.2.K(3) 

Maine should add a requirement the public notice contain the DEP contact person 

for the licensing action. See 40 CFR 70. 7(h)(2). 

16. Chapter 140.2.S 

Maine's proposed rule extends the permit terms and conditions when a complete 

renewal application as determined by the Department, is submitted at least 6 

months prior to expiration but no earlier than 18 months. Part 70 allows a state 

program to either extend the permit terms and conditions or extend the permit. 

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Forty CFR 70.4(b)(l0) states: 

"A requirement under State law that, if a timely and complete application 

for a permit renewal is submitted, consistent with §70.5(a)(2), but the 

State has failed to issue or deny the renewal permit before the end of the 

term of the previous permit, then: 

(i) The permit shall not expire until the renewal permit has been 

issued or denied and any permit shield that may be granted 

pursuant to §70.6(f) may extend beyond the original permit term 

until renewal; or 

(ii) All the terms and conditions of the permit including any permit 

shield that may be granted pursuant to §70.6(f) shall remain in 

effect until the renewal permit has been issued or denied." 

Although subparagraphs (i) and (ii) allow a facility to continue to legally operate 

when a permit is extended, the ability to modify an extended permit is different 

between the two subparagraphs. If a state wants to retain the ability to modify an 

~xtended permit it must incorporate the language on subparagraph (i). This 

language extends the permit, thus allowing a permit to be modified. 

Subparagraph (ii) is limited to extending the permit's term and conditions so there 

is no longer any permit to modify. 

17. Chapter 140, Appendix B, Section B 

In the last few years EPA published requirements under 40 CFR part 63 for diesel 

generators and small boilers. Maine should consider removing these emission 

units, listed as items B-2 and B-3, from the list since they are subject to an 

applicable requirement. 

18. Chapter 140.3.E(7)(b)(xiii)(d) 

This section states: 

"The method(s), specified in the source's license, used for determining the 

compliance status of the source, currently and over the reporting period; 

and .. . " 

Forty CFR 70.6(c)(5)(iii)(B) is broader because it requires the source to determine 

compliance using other available information. 

"The identification of the method(s) or other means used by the owner or 

operator for determining the compliance status with each term and 

condition during the certification period. Such methods and other means 

shall include, at a minimum, the methods and means required under 

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paragraph (a)(3) of this section . . . " 

Maine should revise Chapter 140.3.E(7)(b)(xiii)(d) to also include information not 

specifically required by the license when determining the compliance status. 

19. Chapter 140.7.A(S): There appears to be a typo withln this section. 

"Incorporates any other type of change which the Administrator has 

determined as part of the approved Part 70 program to be similar to those 

in paragraphs 40 CFR 60 § 70.7(d)(l)(i) through (iv)." 

20. The current introductory language to the list of insignificant activities based on 

emission or production rates does not specifically require the state to include these 

activities in a Chapter 140 license if the activity is subject to an applicable 

requirement. We recommend Maine revise the current language as follows: 

"The following units and activities are insignificant based on size or 

production and shall be listed on the Chapter 140 license application. The 

activities will eut ma;· flOt be included in the Chapter 140 license if the 

activity is subject to an applicable requirement." 

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