IN THE MATTER OF: 

ILLINOIS POLLUTION CONTROL BOARD 

July 25, 2013 

) 

) Rl3-ll 

I EPA ATTACHMENT NO. _!l_ 

NATIONAL AMBIENT AIR QUALITY 

STANDARDS, USEPA REGULATIONS 

(through December 31, 2012) 

) (Identical-in-Substance Rulemaking- Air) 

) 

Adopted Rule. Final Order. 

OPINION AND ORDER OF THE BOARD (by J.A. Burke): 

This rulemaking updates the ambient air quality standards in the Board's air pollution 

regulations (35 Ill. Adm. Code 243) to make them confom1 with National Ambient Air Quality 

Standards (NAAQS) 1 adopted by the United States Environmental Protection Agency (USEPA) 

pursuant to section 109 of the Clean Air Act (CAA) (42 U.S.C. § 7409 (2011)). This is the 

initial proceeding under a new identical-in-substance mandate adopted in P.A. 97-945 (eff. Aug. 

10, 2012) to ensure that Illinois' regulations reflect USEPA's most recent NAAQS. 

Today the Board adopts amendments that replace all existing Illinois ambient air quality 

standards with standards de1ived directly from the federal NAAQS codified in 40 C.F.R. 50. As 

explained below, the Board intends the Illinois ambient air quality standards adopted in this 

proceeding to be identical-in-substance with their federal counterpm1s, as "identical-insubstaJ1ce" is defined by Section 7.2(a) of the Environmental Protection Act (Act) (415 ILCS 

5/7.2(a) (2012)). 

Section 1 O(H) of the Act ( 415 ILCS 511 O(H), as added by P .A. 97-945 ( eff. Aug. 1 0, 

2012)), mandates this rulemaking requiring the Board to "adopt ambient air quality standards 

specifYing the maximum pe1missible shm1-term a11d long-te1m concentrations of various 

contaminants in the atmosphere; those standards shall be identical in substance to the national 

aJnbient air quality sta11dards promulgated by ... the United States Environmental Protection 

Agency in accordance with Section 109 of the Clean Air Act [(42 U.S.C. § 7409)]." 415 ILCS 

5/lO(H). 

Section IO(H) of the Act (415 ILCS 5/lO(H) (2012)) and Section l-5(c)(l) of the 

Administrative Procedure Act (APA) (5 ILCS 100/5-l-5(c)(l) (2012)) also provide that Title VII 

of the Act a11d Section 5-35 of the APA (5 ILCS 100/5-35 (2012)) do not apply to this 

proceeding. Accordingly, the Board did not adopt a "First Notice" proposal and a "Second 

Notice" proposal for review by the Joint Committee on Administrative Rules (JCAR). However, 

as provided in Section I O(H) of the Act, a11d as explained in the two following segments of this 

opinion a11d order, the Board, before adopting final rule amendments, provided notice of the May 

16, 2013 rulemaking proposal in the May 31, 2013 issue of the Illinois Register, held one public 

hearing on the proposal on June 26, 2013 in Springfield, as required by the federal Clean Air Act 

1 Throughout this opinion and in the regulatory text, the Board uses the abbreviation "NAAQS" 

to refer to a single standard and "NAAQS" to refer to multiple sta11dards. 
(33 U.S.C. § 7410(a) (2011)), and allowed for public comment for 45 days after publication of 

the Illinois Register notices, until July 15, 2013. 

The Board reserved this docket to accommoda,te the initial set of amendments necessary 

to conform the Illinois ambient air quality standards to the federal NAAQS, as adopted and 

amended by USEPA through December 31, 2012. Board action was necessary to amend the 

Illinois ambient air quality standards to conform with the NAAQS adopted by USEP A, as 

amended through calendar year 2012. 

The Board prefaces this opinion with procedural matters. The substantive discussions 

follow the procedural matters. 

PUBLIC COMMENTS 

The Board adopted a proposal for public comment in this matter on May 16, 2013. A 

Notice ofProposed Amendments appeared in the May 31,2013 issue of the Illinois Register, at 

37 Ill. Reg. 7316. The Board invited public comment on the proposed amendments. The Board 

received public comments on that proposal for 45 days after that date of publication, until July 

15, 2013. During the public comment period, the Board received comments from the Illinois 

Environmental Regulatory Group (IERG): 

PC I First Notice Comments of IERG, by Alec M. Davis, General Counsel (dated July 

15, 2013) 

By PC I, IERG supported the approach taken by the Board in the May 16,2013 proposal 

for public comment. IERG maintains in PC I that the Board misapprehended that an area 

designation under the 2008 eight-hour NAAQS for ozone would effect the sunset of the 1979 

one-hour ozone standard. IERG explained that USEPA's June 15, 2004 area designations under 

the 1997 eight-hour NAAQS for ozone was the triggering event. The Board has corrected the 

text of the adopted rules by removing the 1979 one-hour standard, as is discussed in the 

appropriate segment of the following discussions. 

FEDERALLY REOUIRED PUBLIC HEARING 

The Board expects that the Illinois Environmental Protection Agency (Agency) will 

submit the present amendments as a revision to the Illinois State Implementation Plan (SIP) for 

various contaminants pursuant to section 110 of the federal Clean Air Act (42 U.S.C. § 7410(a) 

(2011) and the implementing USEPA regulations. See 40 C.F.R. 51.102 and appendix V (2012). 

The Board held a public hearing in Springfield on June 26, 2013 in this mlemaking for 

the purpose of allowing interested members of the public to comment on the proposed 

amendments and the anticipated SIP revision that will result from their adoption. The Agency 

and the Illinois Environmental Regulatory Group (IERG) appeared at the hearing, and Mr. David 

Kolaz, fmmerly Chief of the Agency's Bureau of Air, presented testimony on behalf of IERG. 

Mr. Kolaz testified that the Board misapprehended that an area designation under the 2008 eighthour NAAQS for ozone would effect the sunset of the 1979 one-hour ozone standard. Mr. Kolaz 
asserted that it was the June 15, 2004 USEPA area designations under the 1997 eight-hour 

NAAQS for ozone that caused the sunset of the 1979 NAAQS. The Board has corrected the text 

of the adopted mles by removing the 1979 one-hour standard, as is discussed in the appropliate 

segment of the following discussions. 

DUE DATE AND SCHEDULE FOR COMPLETION 

The Board must complete action to adopt amendments within one year of the date when 

USEPA has revised the NAAQS. 415 ILCS 5/7.2(b). Since USEPA adopted all of the federal 

NAAQS more than one year before the effective date ofP.A. 97-945, the Board is interpreting 

that this initial round of amendments must be completed before August 10, 2013. Fulfilling the 

one-year mandate before that date will require proceeding according to the following schedule: 

Due date: 

Proposal adopted date: 

Illinois Register publication date: 

Public hearing date: 

End of 45-day public comment period: 

Adoption date: 

Possible filing and effective date: 

Possible Illinois Register publication date: 

August 10, 2013 

May 16,2013 

May 31,2013 

June 26, 2013 

July 15,2013 

July 25, 2013 

August 5, 2013 

August 15, 2013 

OVERVIEW OF THE FEDERAL NAAQS AND THIS PROCEEDING 

The amendments adopted today are intended to make the Illinois ambient air quality 

standards identical-in-substance to the NAAQS adopted by USEP A. Today's amendments 

include USEP A revisions and ancillary actions, such as USEP A approvals of reference methods 

and equivalent methods, through December 31,2012. The following table outlines the 

discussions and acts as a table of contents: 

Topical Heading Page 

The Context of This Identical-in-Substance Proceeding 6 

Overview of the Federal NAAQS 6 

The Section lO(H) Mandate and the Federal Regulations Included 7 

Replacing the Existing Illinois Ambient Air Quality Standards 7 

Retaining the Existing Illinois Stmcture: Combining a Critelia 8 

Pollutant 

Use of the Singular or Plural to Refer to Plimary and Secondary 9 

NAAQS 

Standardized Naming of Each NAAQS 9 
Removal of Two Illinois Rules 11 

Removal of the "Nondegradation" Rule 11 

Removal of the "Monitoring" Rule 12 

Inclusion of Prescribed Methods, Required Interpretations, and Special- 13 

Case Methods 

List of Designated Methods 13 

Incorporation of Designated Methods 14 

References to Methods in the Text of the NAAQS 14 

Standardization ofTe1ms: FRMs, FEMs, and List of Designated 15 

Methods 

Codified and Non-Codified FRMs 15 

Non-Codified FEMs 17 

The Difference Between FRMs and FEMs 17 

Interpretations: Conventions for Data Management and Analysis 19 

The Special Case FRMs of Appendices B, 0, and Q 20 

Appendix B: FRM for Total Suspended Particulate Matter 20 

Appendix 0: FRM for Coarse Pmticulate Matter (PM10•2.5) 

Appendix Q: FRM for Lead in Particulate Matter (PM 10) 

20 

21 

Summary Tabulation of the NAAQS and Supporting Appendices 22 

NAAQS for Sulfur Oxides 22 

NAAQS for PM10 and PM2.5 22 

NAAQS for Carbon Monoxide 23 

NAAQS for Ozone 23 

NAAQS for Nitrogen Oxides 24 

NAAQS for Lead 24 

Non-NAAQS Required Monitoring 25 

Summary re Inc01poration of the FRMs, FEMs, and Inte1pretations 25 

Codified FRMs 25 

Non-Codified FRMs 25 

Non-Codified FEMs 25 

Intmpretations 26 

The Special-Case FRMs 26 

Omission of Ancillary Federal Regulations in 40 C.F.R. 53, 58, and 81 26 
Revisions to USEP A Defmitions/Definitions Added 27 

Shifted Meanings and Revisions to the Preamble 27 

Changes in Defmed Terms 28 

Added Defmed Terms 28 

Omitted Defmed Terms 29 

USEP A Rules Added/State Provisions Removed 29 

Incmporation of the NAAQS for the Six Criteria Pollutants 31 

Section 243.120: Particulate Matter 32 

Section 243.122: Sulfur Oxides 36 

Sunset Clause for the 1971 Primary 24-Hour NAAQS for Sulfur 38 

Oxides 

Option 1: Retain the Entire Federal Text with Minimal Deviation 39 

Option 2: Replace the Statement of Inapplicability and Delete One 40 

Exception Statement. 

Option 3: Replace the Statement of Inapplicability with a Statement 41 

That the Board Will Remove the 1971 NAAQS When Conditions 

Are Fulfilled 

Option 4: Replace the Statement of Inapplicability with a Statement 41 

That the Board Will Remove the 1971 NAAQS When USEPA 

Makes Area Designations Under the 2010 One HourNAAQS or 

Removes the 1971 NAAQS 

Option 5: Remove the Sunset Provision in Its Entirety 42 

Selection of Option 3 42 

Section 243.123: Carbon Monoxide 42 

Section 243.124: Nitrogen Oxides 44 

Section 243.125: Ozone 46 

Sunset of the 1979 Primary and Secondary One-Hour NAAQS for 48 

Ozone 

Partial Sunset of the 1997 Primary and Secondary Eight-Hour 49 

NAAQS for Ozone 

Section 243.126: Lead 49 

1978 Primary Calendar Quarterly Average NAAQS for Lead 50 

Non-Inclusion of the 2012 NAAQS for PM2.5 and dPM10 51 

Responses to Requests for Public Comments 53 

Deviations from the Literal Text of the Federal Amendments and Non- 55 

Federally Derived Conections and Clarifications 
Tabulations of Deviations from the Literal Text of the Federal Amendments 56 

and Miscellaneous Board Housekeeping Amendments 

Table I: Deviations from the Text of the Federal Rules 

Table 2: Board Housekeeping Amendments 

ORDER (Text of the Amendments) 

The Context of This Identical-in-Substance Proceeding 

56 

91 

94 

The Board does not engage in substantive review of federal standards in the context of an 

identical-in-substance proceeding. Rather, the Board reviews federal standards only to the extent 

necessary to make a "best fit" for those standards in the context of the Illinois regulatory scheme. 

The Board tries to follow the structure and content of federal regulations where possible. 

This ensures the full incorporation of all necessary elements of the present federal standards, and 

it makes updating the regulations easier when future federal amendments occur. 

Depa11ures from the federal structure may occur for a valiety of reasons and will be noted 

as needed below. Where more stlingent pre-existing State standards exist that will continue in 

effect after incorporation of federal elements, the Board will incorporate a structure that retains 

those State standards. See, e.g., RCRA SubtitleD Amendments (Amendments to 35 Ill. Adm. 

Code 810. 811. and 814). R93-1 0 (Sept. 15, 1993), slip op. at 3-5 (adding required federal 

elements into existing State regulations); Safe Drinking Water Act Regulations, R88-26 (Aug. 9, 

1990), slip op. at 6-7 (retaining more stlingent pre-existing State regulations within the body of 

new federal requirements). 

Overview of the Federal NAAOS 

The federal CAA requires USEPA to assemble a list of air pollutants that "cause or 

contlibute to air pollution which may reasonably be anticipated to endanger public health or 

welfare." 42 U.S.C. § 4208(a)(l) (2011). The purpose is to establish national primary and 

secondary NAAQS. A p1imary NAAQS is intended to protect public health, and a secondary 

NAAQS is intended to protect public welfare. 42 U.S.C. § 4209(b) (2011). USEPA is required 

to periodically review each NAAQS and revise it where USEPA determines that revision is 

necessary. USEP A is further required to establish an independent technical advisory committee 

to aid the periodic reviews of each NAAQS. 42 U.S.C. § 4209(d) (2011). 

To date, US EPA has designated six "criteria" pollutants for establishment of primary and 

secondary NAAQS: 

Carbon monoxide (CO) (see 40 C.F.R. 50.8 (2012)); 

Lead (Ph) (see 40 C.F.R. 50.12 and 50.16 (2012)); 

Nitrogen oxides (NOx) (see 40 C.F.R. 50.11 (2012)); 

Ozone (03) (see 40 C.F.R. 50.9 and 50.15 (2012)); 

Particulate matter (PM) in various, evolving, standards: 

Pa11iculate matter (PM) (see 40 C.F.R. 50.6 (1986)); 
Pru1iculate matter with an aerodynamic diameter of 10 micrometers (}lm) or less 

(PM10) (see 40 C.P.R. 50.6 (2012)); and 

Particulate matter with an aerodynamic diameter of 2.5 micrometers (11m) or less 

(PM2.s) (see 40 C.P.R. 50.7 (2012)); and 

Sulfur oxides (as sulfur dioxide) (S02) (see 40 C.P.R. 50.4, 50.8, and 50.17 (2012)). 

The Section IO(H) Mandate and the Federal Regulations Included 

By P.A. 97-945, the General Assembly has created a new identical-in-substance 

mlemaking subject matter. 2 Effective August 10,2012, the General Assembly revised 415 ILCS 

5/7.2 and 10 to require the Board to adopt rules that are identical-in-substance to regulations 

adopted by USEPA pursuant to 42 U.S.C. § 4209. Those federal regulations are the federal 

NAAQS codified as 40 C.P.R. 50. Thus, 40 C.P.R. 50 is the principal focus of this proceeding. 

The Board, however, must consider exactly which segments of 40 C.P.R. 50 are required and 

whether segments of other federal regulations are necessary to fully incorporate the federal 

NAAQS into the Illinois air regulations. 

The federal NAAQS in 40 C.P.R. 50 rely on at least three other segments ofUSEPA 

regulations. The first segment ofUSEPA regulations relates to US EPA-approved monit01ing 

and testing methods required for demonstrating compliance. See, e.g., 40 C.P.R. 50.4(c), 

50.5(b ), and 50.17( c) (20 12) (specifying the methods for the NAAQS for sulfur dioxide). The 

second segment is the body of mles that prescribe the requirements for assembling, maintaining, 

and operating an ambient air monitoring network-i.e., presc1ibing when, where, and how to use 

the required monitoring and testing methods. See 40 C.P.R. 58 (2012). The third segment is the 

series ofUSEPA area designations, which defme the monitoring areas within each state, and 

which classify the attainment or non-attainment status of each air monit01ing area for each 

criteria pollutant. See 40 C.P.R. 81 (20 12). The applicability of many older NAAQS is 

determined by reliance on those area designations. See, e.g., 40 C.P.R. 50.4(e), 50.9(b), and 

50.12(b) (2012) (co!Tesponding with 35 Ill. Adm. Code 243.122(a)(5), the 1971 primary 

NAAQS for sulfur oxides; 243.125(a)(2), the 1997 one-hour primary and secondary NAAQS for 

0 3; and 243.126(a)(2), the 1978 p1imruy and secondary NAAQS for lead, respectively). 

Replacing the Existing Illinois Ambient Air Qualitv Standards 

In the context of this proceeding, pre-existing State ambient air quality standards exist in 

35 Ill. Adm. Code 243. The Board intended that those standards be consistent with 

co!Tesponding federal NAAQS. See Proposed Air Quality Standards, R72-7 (July 10, 1975), slip 

op. at 4-5, 14 (initial Board adoption of ambient air quality standards). The Board intended no 

more stringent State standard in the Illinois ambient air quality regulations. See !d. at 4-5 

(observing adoption of the federal standards absent a reason to differ). 

2 The stated pwpose was to facilitate adoption of the federal NAAQS and the air pe1mitting 

process in Illinois. See 97th Ill. Gen. Assem., Senate Proceedings, March 29, 2012, at 28; 97th 

Ill. Gen. Assem., House Proceedings, May 25,2012, at 27. 
Over time, the Illinois ambient air quality standards lagged behind adoption of the federal 

NAAQS. See Air Quality Standards Clean-Up: Amendments to 35 Ill. Adm. Code 217. 233. 

and 243, R09-19 (Sept. 22, 2011) (Second Notice opinion and order), slip op. at 4-8, 16; see also 

Air Quality Standards Clean-Up: Amendments to 35 Ill. Adm. Code 217. 233. and 243, R09-19 

(Oct. 20, 20 II), slip op. at 4-7 (adopted mle opinion and order). Thus, the existing Illinois 

NAAQS do not presently include any State requirements that are more stringent than the federal 

NAAQS, and they do not include all of the cunent federal NAAQS. 

The mandate of Section IO(H) of the Act (415 ILCS 5/IO(H) (2012)) arose in this 

context. The mandate requires that the Board adopt standards that are identical-in-substance to 

the federal NAAQS. The mandate fmther allows the Board to adopt more stringent State 

standards by generalmlemaking. See 415 ILCS 5/IO(H) (2012). 

The Act generally requires that identical-in-substance mles closely follow the language 

and stmcture of the corr-esponding federal regulations. See 415 ILCS 5/7.2(a) (2012). The 

Board, however, routinely uses the limited flexibility in the statutory definition of"identical in 

substance" (see 415 ILCS 5/7.2(a) (2102)) to preserve more stringent existing State standards. 

See, e.g., RCRA SubtitleD Amendments (Amendments to 35 Ill. Adm. Code 810. 811. and 814), 

R93-IO (Sept. 15, 1993); Safe Drinking Water Act Regulations, R88-26 (Aug. 9, 1990), at 6-7; 

Pretreatment Regulations, R86-44 (Dec. 3, 1987), at 7, 12, 23. 

Since there are no existing Illinois ambient air quality standards that are more stringent 

than the federal NAAQS, the Board has little reason for significant deviation from the stmcture 

and language of each federal NAAQS. Further, retaining the structure and language of the 

individual NAAQS will facilitate future updates to the Illinois regulations as the federal NAAQS 

continue to evolve. The Board has replaced the structure and language of the existing Illinois 

ambient air quality standards with that of the federal NAAQS. 

For the foregoing reasons, the Board has opted to replace the existing Illinois ambient air 

quality standards with the federal NAAQS. The new language is drawn directly from 40 C.F.R. 

50, retaining the structure and language of the federalmles. There are deviations discussed 

throughout this opinion and order. The Board notes tlrree of the exceptions here. 

Retaining the Existing Illinois Structure: Combining All NAAQS for a Criteria 

Pollutant. The Board has combined the multiple NAAQS for each crite1ia pollutant into a single 

provision. Thus, the primary and secondary NAAQS for PMw and PM2.5 from 40 C.F.R. 50.6, 

50.7, and 50.13 are combined in Section 243.120; the NAAQS for sulfur oxides from 40 C.F.R. 

50.4, 50.5, and 50.17 are combined in Section 243.122; and the NAAQS for ozone from 40 

C.F.R. 50.9, 50.1 0, and 50.15 are combined in Section 243.125; and the NAAQS for lead from 

40 C.F.R. 50.12 and 50.16 are combined in Section 243.126. USEPA itself combined the 

NAAQS for nitrogen oxides into a single provision, in 40 C.F.R. 50.11 (corr-esponding with 35 

Ill. Adm. Code 243.124). There is no need to combine standards as to the federal NAAQS for 

carbon monoxide, as there is only one federal standard, in 40 C.F.R. 50.8 (corr-esponding with 35 

Ill. Adm. Code 243.123). 
Use of the Singular or Plural to Refer to Primarv and Secondarv NAAQS. USEPA 

often uses the plural to refer to primary and secondary NAAQS where both are embodied in a 

single standard. See, e.g., 40 C.P.R. 50.6(a) (1987 primary and secondary 24-hourNAAQS for 

PMw) and 50.9(a) (1997 primary and secondary one-hour NAAQS for ozone). The Board has 

consistently used the singular to refer to NAAQS that embody the primary standard and the 

secondary standard in a single number, which the Board perceives as a single primary and 

secondary standard. See, e.g., 35 Ill. Adm. Code 243.120(a)(I) and 243.125(a)(l) 

( con·esponding with the above-cited federal NAAQS). On the other hand, the Board has used 

the plural where two separate numerical standards are presented. For example, the provision that 

recites the 2010 NAAQS for nitrogen oxides includes a one-hour primary NAAQS and an annual 

average secondary NAAQS. See 40 C.P.R. 50.11 (b) and (c) (2012). See 35 Ill. Adm. Code 

243.124(b) and (c) (corresponding with 40 C.P.R. 50.ll(b) and (c) (2012)). As another example, 

the provision relative to the 1971 eight-hour and one-hour primary NAAQS for carbon monoxide 

recites an eight-hour average concentration and a separate one-hour average concentration. See 

40 C.P.R. 50.8(a)(l) and (a)(2) (2012). 

Standardized Naming of Each NAAQS. To accommodate the combined structure and 

clarify the rules, the Board has standardized the names for each NAAQS. The Boardstandardized names indicate the year that USEP A adopted each standard. Each name indicates 

whether the standard is a primary standard, a secondary standard, or primary and secondary 

standard. Each name indicates the duration of each reported monitoring result-"annual 

averaoe" Hqum1erly averaoe" (or "three-month averaoe") "24-hour" "eio-ht-hour" "three-hour" 0' 0 0 ' ' 0 ' ' 

or "one-hour."3 Each of the standardized names states "NAAQS" followed by the name of the 

particular criteria pollutant-i.e., "carbon monoxide," "lead," :nitrogen oxides," "ozone," 

"PMw" or "PM2.s," or "sulfur oxides." These standardized names are rigidly applied throughout 

the text of the rules, and they are consistently used throughout this opinion. Thus, each 

standardized name for the NAAQS is stmctured as follows: 

[Year] "primary" and/or 

"secondary" [monitoring period] "NAAQS 

for" [pollutant name] 

Each federal NAAQS is discussed below, including consideration of development of the 

standard. That discussion of the individual NAAQS, organized on a priority pollutant-bypriority pollutant basis, explains the Board's selection of each standardized name. 

3 The monitoring for each NAAQS occurs over specific periods, the monitoring results are 

analyzed in specific ways, and the results are reported in a time-period-analyzed basis. Thus, 

some of the NAAQS are reported and considered on a quruterly or annual-average basis. See, 

e.g., 40 C.P.R. 50.4(a) (1971 primary annual average NAAQS for sulfur oxides) and 50.12(a) 

(2008 primary and secondary three-month average NAAQS for lead). Some are reported on a 

shmt-te1m basis of a one-, three-, eight-, or 24-hour average. See, e.g., 40 C.P.R. 50.4(a) (1971 

primary 24-hour NAAQS for sulfur oxides), 50.5(a) (1971 secondary three-hour NAAQS for 

sulfur oxides), 50.8(a) (1971 primary eight-hour NAAQS for carbon monoxide), and 50.13(a) 

(2006 primary and secondary 24-hour NAAQS for PM2.5). In the instance of the shmt-tenn 

averages, the Board has omitted the word "average" when creating a standardized name. 
Using the above-described convention, the standardized NAAQS names (together with the 

conesponding citations to them in the Illinois and federal rules) are tabulated as follows: 

Particulate matter CPMl: 

Standardized N arne 3 5 Ill. Adm. Code 40 C.P.R. 

"1987 primary and secondary 24-hour NAAQS for 243.120(a) 50.6 

PM10" 

"1997 primary and secondary annual average 243.120(b) 50.7 

NAAQS for PM2.s " 

"1997 primary and secondary 24-hour NAAQS for 243.120(b) 50.7 

PM2.s" 

"2006 primmy and secondary annual average 243.120(c) 50.13 

NAAQS for PM2.s " 

"2006 prima1y and secondary 24-hour NAAQS for 243.120(c) 50.13 

PMz.s" 

Sulfur oxides: 

Standardized Name 35 Ill. Adm. Code 40 C.P.R. 

"1971 primary annual average NAAQS for sulfur 243.122(a) 50.4 

oxides" 

"1971 prima1y 24-hour NAAQS for sulfur oxides" 243.122(a) 50.4 

"1971 secondary tluee-hour NAAQS for sulfur 243.122(b) 50.5 

oxides" 

"2010 primary one-hour NAAQS for sulfur 243.122(c) 50.17 

oxides" 

Carbon monoxide: 

Standardized Name 35 Ill. Adm. Code 40C.P.R. 

"1971 eight-hour and one-hour NAAQS for carbon 243.123 50.8 

monoxide" 

Nitrogen oxides: 

Standardized N arne 3 5 Ill. Adm. Code 40 C.P.R. 

"1971 prima1y annual average NAAQS for 243.124(a) 50.ll(a) 

nitrogen oxides" 

"2010 primary one-hour NAAQS for nitrogen 243.124(b) 50.11(b) 

oxides" 

"1971 secondmy annual average NAAQS for 243.124(c) 50.ll(c) 

nitrogen oxides" 
Ozone: 

Standardized Name 

"1979 primary and secondary one-hour NAAQS 

for 0 3" 

"1997 primary and secondary eight-hour NAAQS 

for 0 3" 

"2008 primmy and secondary eight-hour NAAQS 

for 0 3" 

Lead: 

35 Ill. Adm. Code 40 C.F.R. 

None 50.9 

243.125(a) 50.10 

243.125(b) 50.15 

Standardized Name 35 Ill. Adm. Code 40 C.F.R. 

"1978 primary and secondary quarterly average 243.126(a) 50.12 

NAAQS for lead"4 

"2008 primary and secondary three-month average 243.126(b) 50.16 

NAAQS for lead" 

Removal of Two Illinois Rules 

The removal of two existing Illinois mles requires brief specific discussion. The 

principal reason for their removal is that these mles are not directly derived from the federal 

NAAQS. The first is the non-degradation clause of35 Ill. Adm. Code 243.104. The second is 

the monitoring provision of35 Ill. Adm. Code 243.106. Especially in the case of the 

"nondegradation" mle, the Board does not want misunderstanding to arise by the removals. 

Removal of the "N ondegradation" Rule. The non-degradation rule predates the 

Enviromnental Protection Act. The Board adopted the mle from earlier mles of the Air Pollution 

Control Board. See Emission Standards, R71-23 (Api". 13, 1972), slip op. at 44-45. When 

adopting the mle, the Board explained that non-degradation "embodies the principle ... that 

parts of the State now clean shall not be unnecessarily degraded." !d. The mle itself is less clear 

than that brief description. The Board has removed the non-degradation clause of 3 5 Ill. Adm. 

Code 243.104 because (I) it might conflict with a newly added federalmle; (2) it is not 

necessary in the context ofNAAQS; and (3) it is not possible to correct its flaws in the context of 

this proceeding. 

Initially, the non-degradation clause may conflict the federal non-degradation 

requirement in 40 C.F.R 50.2(c) that the Board has incorporated at 35 Ill. Adm. Code 243.102(c). 

That statement, added to the Illinois rules, is as follows: "The promulgation of prin1ary and 

secondary NAAQS must not be considered in any manner to allow significant deterioration of 

existing air quality in any portion of this State." 35 Ill. Adm. Code 243.102(c). To the extent 

4 This assumes that the Board does not omit the 1978 primary and secondary NAAQS for lead, 

as is discussed beginning on page 52 of this opinion and order. 
that the clause relates to the NAAQS themselves, the differences between the Illinois mle and the 

newly added federal statement could conflict. Fm1hennore, by incorporating the federal 

language in 35 Ill. Adm. Code 243.102(c), the Illinois mles retain the intent of35 Ill. Adm. Code 

243.104 that air quality in Illinois will not be degraded. 

Second, the Board views non-degradation as directly related to air permitting, not as a 

segment of the federal NAAQS. To the extent that the Illinois non-degradation mle does not 

directly relate to the ambient air quality standards, the statement is not necessary in the present 

context. This is the pJinciple embodied in the federal Prevention of Significant Degradation 

(PSD) requirements. See 42 U.S.C. §§ 7470 et seq. (2011); 40 C.F.R. 51.166 and 52.21 (2012). 

Finally, the language of the mle is flawed. The opening statement imposes no 

requirement. Use of the word "will be maintained" is a statement of present intent, which does 

not impose an imperative, as would language that used a word such as "must." The second 

sentence is ambiguous as to the meaning of"lowered." Generally, a "lowered" pollutant loading 

is an improved air quality. A higher pollutant loading is a degraded air quality. Use of the word 

"degraded" in place of "lowered" would remove this ambiguity. The Board cannot amend the 

mle in this way in the context ofthis identical-in-substance proceeding. 

Removal of the "Monitoring" Rule. Existing 35 Ill. Adm. Code 243.106 requires the 

use of fixed or mobile monit01ing stations located beyond the premises on which an emissions 

source is located, "according to the guidelines for established monitoring networks" that USEPA 

has developed. USEPA has codified the requirements for design, location, and operation of 

monitoring networks as 40 C.F.R. 58. See 40 C.F.R. 50 (2012). 

The Board has removed the Illinois monitoring provision for several reasons. Initially, 

while imp011ant to implementation of the NAAQS, this provision is not a necessary segment of 

the NAAQS themselves. USEPA codified the monit01ing network requirements separately from 

the NAAQS. Further, the authority used by USEPA for adoption of the monitoring network 

requirements does not include "Section I 09 of the Clean Air Act" as required by the present 

identical-in-substance mandate. See 415 ILCS 5/10(H), as added by P.A. 97-945, eff. Aug. 10, 

2012; 40 C.F.R. 58 (2012) (source note). Second, the federal requirements for design, location, 

and operation of monitoring networks are self-in1plementing. See, e.g., 40 C.F.R. 50.10(a) and 

50.1l(a) (2012). Thus, no Illinois provision is necessary in this regard. Third, the vatious 

NAAQS require monitoring in compliance with specified procedures that incorporate the federal 

standards for design, location, and operation of monit01ing networks. Those standards are 

referenced in several of the methods and procedures required for monitoring. See Appendices A1, A-2, B, C, G, H, I, J, K, L, N, 0, P, Q, R, S, and T to 40 C.F.R. 50 (2012). 

N evet1heless, should the record indicate that the Board must retain a provision relative to 

design, location, and operation of monitoring stations, the Board could retain 35 Ill. Adm. Code 

243.106 revised to read as follows: 

All monitoring performed to fulfill the requirements of this Part must be 

perfotmed at stations and networks of stations designed, located, and operated 
according to plans approved by USEP A according to the requirements of 40 

C.F.R. 58. 5 

Inclusion of Prescribed Methods, Required Interpretations, and Special-Case Methods. 

USEPA has approved multiple methods for use in demonstrating compliance with each 

NAAQS. The methods that the standards require for determining compliance are an essential 

aspect of the federal NAAQS. Different methods can produce different measurements. Thus, 

USEP A has specified the methods required for use and reserved authority to itself for approval 

of alternative methods. 

The approved methods are of three types: (!)codified reference methods, (2) USEPAdesignated reference methods, and (3) USEP A-designated equivalent methods. Each NAAQS 

refers to a reference method that is codified in an appendix to 40 C.F.R. 50. Many of the 

NAAQS finther allow the alternative use of another USEP A-designated reference method. 

Other NAAQS allow the alternative use of a USEP A-designated equivalent method. USEPA has 

further added appendices to 40 C.F .R. 50 that recite data handling conventions for some of the 

NAAQS. The following paragraphs outline the considerations relative to inclusion of these 

various methods-related materials into illinois NAAQS mles. 

List of Designated Methods. USEP A designates methods for use in monitoring ambient 

air quality by prescribed procedures. 40 C.F.R. 53.2 and 53.3 (2012); see also 40 C.F.R. 53.11, 

53.14, and 53.16 (2012) (relating to cancellation, modification, and supersession of methods 

designations, respectively). Under federal law, USEPA's designation of a method is effective on 

the date of Federal Register publication. 40 C.F.R. 53.8(a) (2012). USEPA later compiles all of 

the methods designations into a single reference document known as the "List of Designated 

Reference and Equivalent Methods," from the USEP A, National Exposure Research Laboratory 

(List of Designated Methods). 40 C.F.R. 53.8(c) (2012). Thus, there is a short time between 

when a designated method is available for use and when it appears in the List of Designated 

Methods. 

The List of Designated Methods identifies the individual methods that are permissible for 

demonstrating compliance with each NAAQS, providing the following infonnation items: (!) 

the method type; (2) the method source; (3) the method title; (4) a description of the method 

procedure, which may include notes on use of the method; (5) one or more citations to Federal 

Register notices pertaining to USEP A designation of each method; and ( 6) the date of any later 

modifications of the method (in some of the entries). Separate tabulations repeat some of the 

methods identifications in a summary form, including a "method code" number. Finally, the List 

of Designated Methods includes a listing of methods sources and contact information. The List 

of Designated Methods includes all non-codified USEPA-designated reference methods and 

equivalent methods. The List does not include all of the codified reference methods. 

5 The Board would notmally incorporate 40 C.F.R. 58 by reference when imposing its 

requirements. The Board, however, does not believe that incorporation by reference is necessary 

when requiring use of a plan that is approved by USEP A as compliant with 40 C.F.R. 58. 
The latest version of the List of Designated Methods is dated December 17, 2012. This 

edition of the List includes all methods designated by USEPA through that date. USEPA 

designates reference method and equivalent methods on an ongoing basis. When USEP A 

designates a method, it publishes a Federal Register notice of the designation. USEP A also 

posts a link to information about the newly designated reference method and equivalent methods 

on the Technology Transfer Network, Ambient Monitoring Technology Infmmation Center 

(TTN-AMTIC) website. 6 USEPA periodically updates the List of Designated Methods to 

include the federal reference methods (FRMs) and federal equivalent methods (FEMs) 

designated since the last version of the List. 7 For example, the December 17,2012 version of the 

List added equivalent methods designated by USEPA on September II, 2012 and October 5, 

2012. See List of Designated Methods at 2; 77 Fed. Reg. 60985 (Oct. 5, 2012); 77 Fed. Reg. 

55832 (Sept. 11, 20 12). 

Incorporation of Designated Methods. The Board will incorporate by reference all 

USEPA methods designations into the Illinois NAAQS mles. For those methods listed in the 

List of Designated Methods, the incorporation by reference in 35 Ill. Adm. Code 243.108 will 

rely on the latest version of the List to identify the methods designated for each NAAQS. For 

those methods that have not yet appeared in the List as of the date of adoption of future 

amendments, the Board will include incorporation by reference to the Federal Register notice of 

the USEP A designation. 

When conducting the necessary semiannual reviews ofUSEPA actions to determine what 

identical-in-substance mlemaking action is necessary relative to the NAAQS, the Board will 

check the TTN-AMTIC website for any updates to the list or USEP A methods designations that 

may exist only in the form of a Federal Register notice, and either update the version of the List 

of Designated Methods incorporated by reference or incorporate by reference Federal Register 

notices, as appropriate. 

As a matter of Illinois law, inclusion of a USEP A-designated reference method or 

equivalent method is effective on the date that the Board files an amendment to incorporate that 

method by reference. See 5 ILCS 100/5-40(d) (2012). This will result in an unavoidable delay 

up to a year (see 415 ILCS 5/7.2(b) (2012)) between the dates when USEPA has designated a 

new method and when the use of that method is acceptable as a matter of Illinois law. 

References to Methods in the Text of the NAAOS. Most of the federal NAAQS refer 

to designated methods in the text of the NAAQS by reference to methods "designated in 

accordance with part 53 of this chapter." See 40 C.F.R. 50.4(c), 50.5(b), 50.6(c)(l) and (c)(2), 

50.7(a)(l) and (a)(2), 50.8(b)(1) and (b)(2), 50.9(a), 50.10(a), 50.11(a) and (d)(2), 50.13(a)(1) 

and (a)(2), 50.15(a), 50.16(a)(l) and (a)(2), and 50.17(c). One NAAQS omits this language, 

even though the use ofUSEPA-designated methods is required. See 40 C.F.R. 50.12(a) (2102) 

(lead). 

6 http://www.epa.gov/ttn/amtic/cpreldoc.html. 

7 The four prior published versions of the List of Designated Methods were dated June 6, 2012, 

October 12, 20 II, April 1, 2011, and Febmary I, 2011. 
The Illinois NAAQS mles will specifY use of methods "designated by US EPA and listed 

in List of Designated Methods, incorporated by reference in Section 243.108." See 35 Ill. Adm. 

Code 243.120(a)(3)(A), (a)(3)(B), (b)(l)(A), (b)(l)(B), (c)(l)(A), and (c)(l)(B); 243.122(a)(3), 

(b)(2), and (c)(3); 243.123(b)(l) and (b)(2); 243.124(d)(l) and (d)(2); 243.125(a)(l), (b)(!), and 

(c)(!); and 243.126(a)(l ), (b )(I )(A), and (b )(I )(B). USEP A alone has authority to designate 

monitming methods. See 40 C.F.R. 53.8(a), 53.ll(a), 53.14(c), and 53.16(a) (2012); see also 42 

U.S.C. § 7403( c) (2011) (requiring USEP A to establish "methods for sampling, measurement, 

monitoring, analysis, and modeling of air contaminants"). The language chosen by the Board for 

each of the NAAQS translates this federal requirement into their Illinois counterpatts. 

Standardization of Terms: FRMs, FEMs, and List of Designated Methods. In the 

course of identical-in-substance mlemaking, the Board routinely attempts to standardize the 

language used where variation appears in the language of federalmles. That is tme in this 

proceeding in several regards, but particularly in the naming of monitoring methods. Other shifts 

in phrasing are considered in later segments of this discussion. 

To standardize the naming of USEP A -designated methods, the Board has combined 

usage from two segments ofthe US EPA regulations: (I) the NAAQS mles themselves; and (2) 

the mles pettaining to methods designations. As a result, the Illinois NAAQS mles define the 

standardized terms "federal reference method" and "federal equivalent method" in 35 Ill. Adm. 

Code 243.102. 

The definition of "federal reference method" combines the parallel federal definitions of 

"reference method," in cmTesponding 40 C.F.R. 50.1(£), and "federal reference method" in 40 

C.F.R. 53.1, which is in the provisions for approval of these methods. The Board has further 

used the defmed abbreviation "FRM" for this term throughout the substantive provisions of the 

NAAQS-derived regulations. This is without regard to whether the method is codified as an 

appendix to 40 C.F.R. 50 or the method is a USEPA-designated reference method that is based 

on a method codified as an appendix. 

Similarly, the definition of"federal equivalent method" combines the parallel federal 

definitions of"equivalent method," in corresponding 40 C.F.R. 50.l(g), and "federal equivalent 

method" in 40 C.F.R. 53.1. The Board has used the defined abbreviation "FEM" to refer to the 

equivalent methods. 

The following discussions use the abbreviations "FRM" and "FEM" to refer to the 

methods. The discussions distinguish between the codified and USEP A-designated non-codified 

FRMs where necessary. 

Codified and Non-Codified FRMs. The federal NAAQS include two types ofFRMs. 

There are the FRMs codified in appendices to 40 C.F.R. 50, and there are non-codified FRMs 

that USEPA has designated. The federal NAAQS use two distinct phrasings to allow use of 

FRMs. The Board here observes possible inconsistent usage in the federal language, but makes 

no attempt to reconcile the language. The revisions to the federal text that the Board has made 
are limited to standardizations of terms. The Board intends that the Illinois NAAQS rules have 

the same substantive effect as do the federal NAAQS upon which they are based. 

Most of the NAAQS provisions describe the pem1issible FRMs in the following terms: 

"a reference method based on [the reference method cited in the] appendix ... and designated 

[by USEPA]." See 40 C.F.R. 50.6(c)(l) (PM10), 50.7(a)(l) (PM2s), 50.8(b)(l) (carbon 

monoxide), 50.9(a) (ozone), 50.10(a) (ozone), 50.ll(d)(l) (nitrogen oxides), 50.13(a)(l) (PM25), 

and 50.15(a) (ozone) (2012). The List of Designated Methods includes numerous non-codified 

FRMs for these contaminants, but none of the codified FRMs from 40 C.F.R. 50. See List of 

Designated Methods, at 4-9 (16 for PM10), 10-15 (17 for PM2 5), 25-30 (nine for ozone), 31-34 

(20 for carbon monoxide), and 35-41 (26 for nitrogen oxides). The absence of codified FRMs in 

the List for these contaminants is literally consistent with the teim "an FRM based on [the 

reference method cited in] appendix ... and designated by USEPA." 

The Board has followed the federal language very closely in the cmTesponding Illinois 

NAAQS provisions, with three shifts in language discussed in the immediately foregoing 

paragraphs: (I) the Board standardized usage of the defined teim "an FRM"; (2) the Board 

clearly stated the requirement for USEPA-designation of the FRM; and (3) the Board added a 

reference to the List of Designated Methods. Thus, the con·esponding Illinois NAAQS use the 

phrasing "an FRM based on appendix ... and designated by USEP A and listed in List of 

Designated Methods, incorporated by reference in Section 243.108." See 35 Ill. Adm. Code 

243.120(a)(3)(A), (b)(l)(A), and (c)(l)(A) (PM10 and PM25); 243.123(b)(l) (carbon monoxide); 

243.124(d)(l) (nitrogen oxides); and 243.125(a)(l), (b)(!), and (c)(!) (ozone). 

The Board notes the potential for ambiguities in the federal language. The first 

ambiguity concems whether some FRMs are directly available for use when USEPA has 

specified use of "an FRM based on" the codified FRM. The second, related, ambiguity is 

whether a codified FRM is available for use even though that FRM is not included in the List of 

Designated Methods. 

The NAAQS for carbon monoxide, ozone, nitrogen oxides, PM10, and PM2.5 require use 

of an FRM "based on" an associated appendix to 40 C.F.R. 50. See 40 C.F.R. 50.6(c)(l) (2012) 

("based on appendix J" for PM10); 40 C.F.R. 50.7(a)(l) and 50.13(a)(l) (2012) ("based on 

appendix L" for PM2.5); 40 C.F.R. 50.8(b)(l) (2012) ("based on appendix C" for carbon 

monoxide); 40 C.F.R. 50.9(a), 50.10(a), and 50.15(a) (2012) ("based on appendix D" for ozone); 

40 C.F.R. 50.ll(d)(l) (2012) ("based on appendix F" for nitrogen oxides). Further, the List of 

Designated Methods does not include listings for Appendices C, D, F, J, and L to 40 C.F.R. 50, 

relative to carbon monoxide, ozone, nitrogen oxides, PM10, and PM2.5, respectively. The general 

rules relative to FRM designations for PM 10, PM2.

5, carbon monoxide, ozone, and nitrogen 

oxides require that the FRM "meets all requirements specified in" the particular appendix 

associated with that FRM. See 40 C.F.R. 53.2(a)(2), (a)(3), and (b) (2012). 

The NAAQS for sulfur oxides add to the potential for ambiguity. The three 1971 

NAAQS for sulfur oxides (the 1971 primary annual average NAAQS for sulfur oxides, the 1971 

primary 24-hour NAAQS for sulfur oxides, and the 1971 secondary three-hour NAAQS for 

sulfur oxides) use a second te1m to refer to the permissible FRM: "the reference method 
described in appendix [A-2]." See 40 C.P.R. 50.4(c) and 50.5(b) (2012). The general rules for 

methods designations allow no manual method other than the codified FRM in appendix A-2 to 

40 C.P.R. 50. See 40 C.P.R. 53.2(a)(l) (2012). The general rules further specify that an 

automated FRM for sulfur oxides "must use the measurement principle and calibration procedure 

specified in" Appendix A-I to 40 C.P.R. 53.2(b) (2012). Consistent with use restricted to the 

codified FRM for sulfur oxides is the fact that the only FRM included in the List of Designated 

Methods is the manual method of Appendix A-2 to 40 C.P.R. 50. See List of Designated 

Methods, at 18. 

On the other hand, the 2010 plimary one-hour NAAQS for sulfur oxides uses the tenn 

"an FRM based on appendix [A-2] or A-1." See 40 C.P.R. 50.17(c) (2012). This language is 

that used for the NAAQS for which no codified FRM is included in the List of Designated 

methods. 

The NAAQS for lead are also unique cases that enhance the potential for ambiguity. The 

lead NAAQS require an FRM "based on appendix G." See 40 C.P.R. 50.12(a) and 50.!6(a)(l) 

(2012). The only FRM included in the List of Designated Methods is Appendix G. List of 

Designated Methods, at 42. Further, the general rules for FRM designation explicitly state that 

"other manual methods for lead will not be considered for a reference method determination," 

and they do not provide for approval of automated FRMs for lead. 40 C.P.R. 53.2(a)(l) and (b) 

(2102). 

The Board has made no effort to clarify the federal language in this regard. The Board 

has followed the federal language with the above-described changes, retaining any potential 

ambiguities. If there is any difference in meaning between "an FRM based on" and "the FRM 

described in" language, the Board does not wish to blur any distinctions. The only distinction 

that the Board makes is that some FRMs are codified and others are non-codified. Fmther, the 

Board observes that only two of the codified FRMs are included in List of Designated Methods. 

From a practical perspective, in the context of this identical-in-substance proceeding, the 

main difference between a codified FRM and a non-codified FRM is how each type is 

incorporated by reference into the Illinois regulations. From the broader perspective of what 

USEPA intended as to the meaning of the rules, the Board cannot mitigate any potential for 

ambiguity. 

Non-Codified FEMs. The third type ofUSEP A-designated method is an FEM. All of 

the FEMs are non-codified. USEPA refers to them all (often conjunctively with FRMs) with 

uniform language: "an equivalent method designated in accordance with pa1t 53 of this chapter." 

See 40 C.P.R. 50.4(c), 50.5(b), 50.6(c)(2), 50.7(a)(2), 50.8(b)(2), 50.ll(d)(2), 50.13(a)(2), 

50.15(a), 50.16(a)(2), and 50.17(c) (2012) (NAAQS for sulfur oxides, PM10, PM2.5, carbon 

monoxide, nitrogen oxides, ozone (except the 1997 NAAQS), and lead). The federal regulations 

include two consistent variations on this language: (I) the NAAQS for lead omits "designated in 

accordance with part 53 of the chapter" (see 40 C.P.R. 50.12(a) (2012)); and (2) the 2010 

NAAQS for sulfur oxides capitalizes "Federal Equivalent Method" and adds "(FEM)" (see 40 

C.P.R. 50.17(c) (2012)). The List of Designated Methods includes all of the FEMs. See List of 

Designated Methods, at 4-9 (II for PM10), 10-15 (17 for PM2_s), 18-24 (34 for sulfur oxides), 25-
30 (23 for ozone), 31-34 (none for carbon monoxide), 35-41 (five for nitrogen oxides), and 42-45 

(27 for lead). 

Only two federal NAAQS do not refer to the use of an FEM. These are the 1997 primary 

and secondary one-hour and eight-hour NAAQS for ozone. Instead, these NAAQS recite only 

the use of an FRM. See 40 C.P.R. 50.9(a) and 50.10(a) (2012). The Board could fmd no 

explanation why these standards do not refer to FEMs. See 62 Fed. Reg. 38856 (July 18, 1997) 

(adopting the 1997 standards). Further, the List of Designated Methods includes 23 FEMs for 

ozone. See List of Designated Methods at 25-30. 

The Board has uniformly used "an FEM designated by USEP A and listed in List of 

Designated Methods, incorporated by reference in Section 243.108" throughout all of the 

NAAQS, except for the 1997 p1immy and secondary NAAQS for ozone. See 35 Ill. Adm. Code 

243.120(a)(3)(B), (b)(l)(B), and (c)(l)(B); 243.122(a)(3), (b)(2), and (c)(3); 243.123(b)(2); 

243.124(d)(2); 243.125(a)(l), (b)(!), and (c)(!); and 243.126(a)(l) and (b)(l)(A) (NAAQS for 

PM10, PM2.5, sulfur oxides, carbon monoxide, nitrogen oxides, ozone (2008 NAAQS), and lead. 

This meant confmming the two consistent variations in language of the federal NAAQS for 

sulfur oxides and lead, cited above. See 35 Ill. Adm. Code 243.122(a)(3), (b)(2), and (c)(3) and 

243.126(a)(l) and (b)(l)(B). 

On the other hand, the Board has not tried to reconcile the potential inconsistency with 

regard to the 1997 ozone standards. The Board has added no references to FEMs relative to 

those two NAAQS. See 35 Ill. Adm. Code 243.125(a)(l) and (b)(!). 

The Difference Between FRMs and FEMs. From the practical perspective of use, the 

Board sees no difference between an FRM (whether codified or non-codified) and an FEM. The 

federal NAAQS authmize the use of either type of method. Still, there is a qualitative difference 

between the two types of methods. USEP A recited as follows with regard to methods for PM25 : 

[R ]eference methods ... are intended to provide for unifonn, reproduceable [sic] 

measurements of ... [ciiteria pollutant] concentrations in ambient air to serve as a 

measurement standard for the primary purpose of making comparisons to the 

NAAQS. Equivalent methods ... allow for the consideration and introduction of 

new and innovative ... [ Ciiteiia pollutant] measurement technologies for this 

same purpose, provided such new technologies can be shown to provide ... 

[ ciite1ia pollutant] measurements comparable to reference measurements under a 

variety of typical monitoring conditions. 62 Fed. Reg. 38764, 65 (July 18, 1997). 

The Board observes that the federal mles divide FEMs for PM2.5 into three classes: Class 

I, Class II, and Class III. The distinctions are based on the analyzer used. See 40 C.P.R. 53.1 

(2012) (definitions of"Class I equivalent method," "Class II equivalent method," and "Class III 

equivalent method"). The perfmmance characteristics and designation procedures for each class 

differs. See 40 C.P.R. 53.3(a)(2) and (a)(3) (2012); table C-4 to subpart C of 40 C.P.R. 53 

(2012). USEPA explained that the classes are intended "[t]o minimize the number and extent of 

perfmmance tests to which candidate equivalent methods are subjected .... " 62 Fed. Reg. 
38764, 66 (July 18, 1997). Since the classes ofPEMs do not relate directly to any NAAQS, the 

Board does not need to include these classes in the Illinois NAAQS rules. 

Interpretations: Conventions for Data Management and Analvsis. Many of the 

federal NAAQS reference "interpretations" that outline the procedure for using monitoring data 

to determine compliance with the NAAQS. All of these interpretations are embodied in an 

appendix to 40 C.P.R. 50. The federal NAAQS require use of the interpretations as follows: 

Appendix H: The 1997 primary and secondary one-hour NAAQS for ozone requires use of 

Appendix H to 40 C.P.R. 50 "to dete1mine when the expected number of days per 

calendar" is below the regulatory threshold level. See 40 C.P.R. 50.9(a) (2012); 

Appendix H to 40 C.P.R. 50 (2012) (introductory paragraph). 

Appendix I: The 1997 primary and secondmy eight-hour NAAQS for ozone requires 

determination of compliance using the "data handling conventions and 

computations" of Appendix Ito 40 C.P.R. 50. See 40 C.P.R. 50.10(b) (2012); 

Appendix I to 40 C.P.R. 50 (2012) (introductory paragraph). 

Appendix K: The 1987 primary and secondary 24-hour NAAQS for PM10 requires 

determination of compliance using the "computations" of Appendix K to 40 

C.P.R. 50. See 40 C.P.R. 50.6(c)(l) (2012); Appendix K to 40 C.P.R. 50 (2012) 

(introductory paragraph). 

Appendix N: The 1997 and 2006 prirnmy and secondary annual average and 24-hour NAAQS 

for PM,.s (four NAAQS) require dete1mination of compliance using the "data 

handling conventions and computations" of Appendix N to 40 C.P.R. 50. See 40 

C.P.R. 50.7(b) and 50.13(b) (2012); Appendix N to 40 C.P.R. 50 (2012) 

(introductory paragraph). 

Appendix P: The 2008 primary and secondary eight-hour NAAQS for ozone requires 

determination of compliance using the "data handling conventions and 

computations" of Appendix P to 40 C.P.R. 50. See 40 C.P.R. 50.15(b) (2012); 

Appendix P to 40 C.P.R. 50 (2012) (introductory paragraph). 

Appendix R: The 2008 primary one-hour NAAOS for sulfur oxides requires determination of 

compliance using the "data handling conventions and computations" of Appendix 

R to 40 C.P.R. 50. See 40 C.P.R. 50.16(b) (20 12); Appendix R to 40 C.P.R. 50 

(2012) (introductory paragraph). 

Appendix S: The 1971 primary annual average and 2010 primary one-hour NAAQS for 

nitrogen oxides (two NAAQS) require determination of compliance using the 

"data handling conventions and computations" of Appendix S to 40 C.P.R. 50. 

See 40 C.P.R. 50.ll(e) and (f) (2012); Appendix S to 40 C.P.R. 50 (2012) 

(introductory paragraph). 
Appendix T: The 20 I 0 primary one-hour NAAQS for sulfur oxides requires determination of 

compliance using the "data handling conventions and computations" of Appendix 

T to 40 C.P.R. 50. See 40 C.P.R. 50.17(b) (2012); Appendix T to 40 C.P.R. 50 

(2012) (introductory paragraph). 

Some of the oldest existing NAAQS do not require use of interpretations, including the 

following: 

The 1971 primary annual average NAAQS for sulfur oxides (see 40 C.P.R. 50.4 (2012)); 

The 1971 primary annual average NAAQS for sulfur oxides (see 40 C.P.R. 50.4 (2012)); 

The 1971 secondary three-hour NAAQS for sulfur oxides (see 40 C.P.R. 50.5 (2012)); 

The 1971 p1imary eight-hour NAAQS for carbon monoxide (see 40 C.P.R. 50.8 (2012)); 

The 1971 primary one-hour NAAQS for carbon monoxide (see 40 C.P.R. 50.8 (2012)); 

The 1971 secondary annual average NAAQS for nitrogen oxides (see 40 C.P.R. 50.11 

(2012)); and 

The 1978 primary and secondary qumterly average NAAQS for lead (see 40 C.P.R. 50.12 

(2012)). 

The Special Case FRMs of Appendices B, 0, and Q. Three codified FRMs are not 

directly relied on by any NAAQS. The Board has included all three FRMs in the Illinois 

NAAQS because each is substantively relied on in another codified FRM. The following 

paragraphs explain the special circumstances of each of these codified FRMs. 

Appendix B: FRM tor Total Suspended Particulate Matter. An old NAAQS for 

particulate matter (PM) f01merly relied on Appendix B to 40 C.P.R. 50. See 40 C.F.R 50.6 

(1983). USEPA retained Appendix B to 40 C.P.R. 50, when USEP A subsequently replaced the 

PM NAAQS with the PM10 NAAQS and Appendix J to 40 C.P.R. 50 for PM10 supplanted 

Appendix B for PM. USEP A did so because Appendix B is substantively referenced in 

Appendix G to 40 C.P.R. 50, for the purposes of the lead NAAQS. See 52 Fed. Reg. 24634, 48 

(July I, 1987). 

The substantive reliance on Appendix B remains in Appendix G to 40 C.P.R. 50. See 

Appendix G to 40 C.P.R. 50 (2012), at~ 5.1.1. For this reason, the Board has retained the 

incorporation by reference to Appendix Bin 35 Ill. Adm. Code 243.108, noting the reference to 

this document in Appendix G to 40 C.P.R. 50. 

Appendix 0: FRM (or Coarse Particulate Matter (PM10•2.5l. USEP A once proposed, 

yet declined to adopt a NAAQS for coarse particulate matter (PM10•2.5). See 71 Fed. Reg. 61144, 

94 (Oct. 17, 2006); 71 Fed. Reg. 2620, 98 (Jan. 17, 2006) (proposing a 24-hour standard of70 

)lg/m3 as 40 C.P.R. 50.13(a)(2)(i)). USEPA, however, adopted the proposed FRM for PM10.25 as 

Appendix 0 to 40 C.P.R. 50. See 71 Fed. Reg. 61144, 230 (Oct. 17, 2006) (NAAQS 

amendments); see also 71 Fed. Reg. 61236, 38 (Oct. 17, 2006) (accompanying amendments to 

40 C.P.R. 53 and 58). USEPA explained as follows: 

An official FRM will be an important element in facilitating consistent research 

on PM10_25 air quality and health effects and in promoting the commercial 
development ofFEMs. In a separate final rule ... [US]EPA is promulgating a 

requirement that States deploy about 60 FRM or FEM PM10_25 monitors as part of 

a new National Core (NCore) multi-pollutant monitoring stations. 71 Fed. Reg. 

61144,212 (Oct. 17, 2006). 

In accompanying amendments to the ambient air quality surveillance requirements, 

USEP A required all states to establish and operate at least one NCore8 monitoring site. USEPA 

provided that Illinois would need to establish and operate one or two additional sites. See 

Appendix D to 40 C.F.R. 58 (2012), at~ 3(a); 71 Fed. Reg. 61236, 39 (Oct. 17, 2006). 

Monitoring for PM10.25 is required at each NCore site. See 40 C.F.R. 58.12(f)(l) (2012); 

Appendix D to 40 C.F.R. 58 (2012), at~ 3(b); see also 40 C.F.R. 58.1 (2012) (definition of 

"NCore"). 

Fmther, Appendix Q to 40 C.F.R. 50 relies on Appendix 0 for descliption of the required 

sampler, sampling period, measurement procedures, etc. See Appendix Q to 40 C.F.R. 50 

(2012), at~~ 1.2 and 3.1. Appendix Q is considered in the following segment of this discussion, 

immediately below. 

Thus, the NCore monitoring provisions sites and Appendix Q to 40 C.F.R. 50 rely on 

Appendix 0 to 40 C.F.R. 50. This is despite the fact that Appendix 0 is not pat1 of an active 

NAAQS. For this reason, the Board has retained the incorporation by reference to Appendix 0 

in 35 Ill. Adm. Code 243.108, noting the reference to this document in Appendix Q to 40 C.F.R. 

50. The Board has also noted that this method is "for use in federally required monitoring by the 

NCore system pursuant to 40 CFR 58." 

Appendix 0: FRM for Lead in Particulate Matter (PM10l.:. USEPA once proposed 

revising the NAAQS for lead, which is lead in ultra-coarse pat1iculate matter (Pb-PM) to lead in 

coarse particulate matter (Pb-PM10). See 73 Fed. Reg. 66964, 88-89 (Nov. 12, 2008). USEPA 

retained the Pb-PM standard, but not the PB-PM standard because the data was insufficient to 

establish the relationship between Pb-PM10 levels and health effects. See id. at 66991. USEP A, 

however, allowed limited use ofPb-PM10 data to establish non-compliance (see id. at 67019) or 

to establish compliance where the levels oflead in the air are anticipated to be substantially 

below the standard and ultra-coarse particles are not expected (see id. at 66991). Thus, USEPA 

adopted the interpretation of the 2008 primary and secondaty three-month average NAAQS for 

lead as Appendix R to 40 C.F.R. 50. Appendix R refers to the FRM for Pb-PM10 in Appendix Q. 

See Appendix R to 40 C.F.R. 50 (2012), at~ 1 (a); 73 Fed. Reg. at 67019-21. 

The substantive reliance on Appendix Q in Appendix R to 40 C.F.R. 50 wanants 

inclusion of Appendix Q in the Illinois NAAQS rules. Appendix Q provides an altemative 

monitoring methodology for the 2008 NAAQS for lead. For this reason, the Board has retained 

the incorporation by reference to Appendix Q in 35 Ill. Adm. Code 243.108, noting the reference 

to this document in Appendix R to 40 C.F.R. 50. 

8 Defined as the "National Core multipollutant monitoring stations" that monitor PM25, speciated 

PM2.5 PM10.2.5, ozone, sulfur dioxide, carbon monoxide, nitrogen oxides, lead, and basic weather 

data. 40 C.F.R. 58.1 (2012). 
Summarv Tabulation of the NAAQS and Supporting Appendices. The following 

tabulation lists all of the federal NAAQS, the codified FRM and any "interpretation" associated 

with each. 

NAAOS for Sulfur Oxides: 

NAAQS: 1971 primary annual average NAAQS for sulfur oxides 

Citations: 40 C.F.R. 50.4(a)/35 Ill. Adm. Code 243.122(a)(l) 

FRM specified: Appendix A-2 to 40 C.F.R. 50 

Citations: 40 C.F.R. 50.4(c)/35 Ill. Adm. Code 243.122(a)(3) 

Interpretation specified: None 

NAAQS: 1971 primary 24-hour NAAQS for sulfur oxides 

Citations: 40 C.F.R. 50.4(a)/35 Ill. Adm. Code 243.122(a)(l) 

FRM specified: Appendix A-2 to 40 C.F.R. 50 

Citations: 40 C.F.R. 50.4(c)/35 Ill. Adm. Code 243.122(a)(3) 

Interpretation specified: None 

NAAQS: 1971 secondary three-hour NAAQS for sulfur oxides 

Citations: 40 C.F.R. 50.5(a)/35 Ill. Adm. Code 243.122(b)(1) 

FRM specified: Appendix A-2 to 40 C.F.R. 50 

Citations: 40 C.F.R. 50.5(b )/35 Ill. Adm. Code 243 .122(b )(2) 

Interpretation specified: None 

NAAQS: 2010 mimary one-hourNAAQS for sulfur oxides 

Citations: 40 C.F.R. 50.17(a)/35 Ill. Adm. Code 243.122(c)(1) 

FRM specified: Appendix A-1 or A-2 to 40 C.F.R. 50 

Citations: 40 C.F.R. 50.17(c)/35 Ill. Adm. Code 243.122(c)(3) 

Interpretation specified: Appendix T to 40 C.F.R. 50 

Federal citation: 40 C.F.R. 50.17(b)/35 Ill. Adm. Code 243.122(c)(2) 

NAAOS (or PM1o and PM,.s: 

NAAQS: 1987 primarv and secondary 24-hour NAAOS for PM10 

Citations: 40 C.F.R. 50.6(a)/35 Ill. Adm. Code 243.120(a)(l) 

FRM specified: Appendix J to 40 C.F.R. 50 

Citations: 40 C.F.R. 50.6(c)(l)/35 Ill. Adm. Code 243.120(a)(3)(A) 

Interpretation specified: Appendix K to 40 C.F.R. 50 

Citations: 40 C.F.R. 50.6(a)/35 Ill. Adm. Code 243.120(a)(l) 

NAAQS: 1997 primary and secondary annual average NAAQS for PM22 

Citations: 40 C.F.R. 50.7(a)/35 Ill. Adm. Code 243.120(b)(l) 

FRM specified: Appendix L to 40 C.F.R. 50 

Citations: 40 C.F.R. 50.7(a)(l)/35 Ill. Adm. Code 243.120(b)(l)(A) 
Interpretation specified: Appendix N to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.7(b)/35 Ill. Adm. Code 243.120(b)(2) 

NAAQS: 1997 primary and secondary 24-hour NAAQS for PM,_5 

Citations: 40 C.P.R. 50.7(a)/35 Ill. Adm. Code 243.120(b)(l) 

PRM specified: Appendix L to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.7(a)(l)/35 Ill. Adm. Code 243.120(b)(l)(A) 

Intetpretation specified: Appendix N to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.7(b)/35 Ill. Adm. Code 243.120(b)(2) 

NAAQS: 2006 primary and secondary annual average NAAQS for PM, 5 

Citations: 40 C.P.R. 50.13(a)/35 Ill. Adm. Code 243.120(c)(l) 

FRM specified: Appendix L to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.13(a)(l)/35 Ill. Adm. Code 243.120(c)(l)(A) 

Interpretation specified: Appendix N to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.13(b)/35 Ill. Adm. Code 243.120(c)(2) 

NAAQS: 2006 primary and secondary 24-hour NAAQS for PM,_5 

Citations: 40 C.P.R. 50.13(a)/35 Ill. Adm. Code 243.120(c)(l) 

PRM specified: Appendix L to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.13(a)(l)/35 Ill. Adm. Code243.120(c)(l)(A) 

Interpretation specified: Appendix N to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.13(c)/35 Ill. Adm. Code 243.120(c)(3) 

NAAOS (or Carbon Monoxide: 

NAAQS: 1971 primary eight-hour NAAQS for carbon monoxide 

Citations: 40 C.P.R. 50.8(a)(l)/35 Ill. Adm. Code 243.123(a)(l) 

PRM specified: Appendix C to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.8(b)(l)/35 Ill. Adm. Code 243.123(b)(l) 

Intetpretation specified: None 

NAAQS: 1971 primary one-hour NAAQS for carbon monoxide 

Citations: 40 C.P.R. 50.8(a)(2)/35 Ill. Adm. Code 243.123(a)(2) 

PRM specified: Appendix C to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.8(b)(l)/35 Ill. Adm. Code 243.123(b)(l) 

Intetpretation specified: None 

NAAOS (or Ozone: 

NAAQS: 1979 primary and secondary one-hour NAAQS for ozone 

Citations: 40 C.P.R. 50.9(a)/No corresponding Illinois provision 

PRM specified: Appendix D to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.9(a)/No corresponding Illinois provision 

Interpretation specified: Appendix H to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.9(a)/No corresponding Illinois provision 
NAAQS: 1997 primary and secondary eight-hour NAAOS for ozone 

Federal citation: 40 C.P.R. 50.10(a)/35 Ill. Adm. Code 243.125(a)(1) 

FRM specified: Appendix D to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.10(a)/35 Ill. Adm. Code 243.125(a)(J) 

Inte1pretation specified: Appendix I to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.JO(b)/35 Ill. Adm. Code 243.125(a)(2) 

NAAQS: 2008 primary and secondary eight-hour NAAOS for ozone 

Federal citation: 40 C.P.R. 50.15(a)/35 Ill. Adm. Code 243.125(b)(J) 

FRM specified: Appendix D to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.15(a)/35 Ill. Adm. Code 243.125(b)(J) 

Inte1pretation specified: Appendix P to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.15(b)/35 Ill. Adm. Code 243.125(b)(2) 

NAAOS (or Nitrogen Oxides: 

NAAQS: 1971 primary annual average NAAQS for nitrogen oxides 

Citations: 40 C.P.R. 50.11(a)/35 Ill. Adm. Code 243.124(a) 

FRM specified: Appendix F to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.11(d)(1)/35lll. Adm. Code 243.124(d)(J) 

Interpretation specified: Appendix S to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.1l(e)/35 Ill. Adm. Code 243.124(e) 

NAAQS: 2010 primary one-hour NAAQS for nitrogen oxides 

Citations: 40 C.P.R. 50.11(b)/35 Ill. Adm. Code 243.124(b) 

FRM specified: Appendix F to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.11(d)(1)/35 ill. Adm. Code 243.124(d)(1) 

Inte1pretation specified: Appendix S to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.11(f)/35 Ill. Adm. Code 243.124(f) 

NAAQS: 1971 secondary annual average NAAQS for nitrogen oxides 

Citations: 40 C.P.R. 50.11(c)/35 Ill. Adm. Code 243.124(c) 

FRM specified: Appendix F to 40 C.P.R. 50 

Citations: 40 C.P.R. 50.11(d)(l)/35 ill. Adm. Code 243.124(d)(l) 

Interpretation specified: None 

NAAOS (or Lead: 

NAAQS: 1978 primary and secondary quarterly average NAAQS for lead 

Citations: 40 C.P.R. 50.12(a)/35 Ill. Adm. Code 243.126(a)(J) 

FRM specified: Appendix G to 40·C.F.R. 50 (relying on Appendix B) 

Citations: 40 C.P.R. 50.12(a)/35 Ill. Adm. Code 243.126(a)(J) 

Interpretation specified: None 
NAAQS: 2008 primary and secondary tln·ee-month average NAAQS for lead 

Citations: 40 C.P.R. 50.16(a)/35 Ill. Adm. Code 243.126(b) 

PRM specified: Appendix G to 40 C.P.R. 50 (relying on Appendix B) 

Citations: 40 C.P.R. 50.16(a)(l)/35 Ill. Adm. Code 243.126(b)(l)(A) 

Interpretation specified: Appendix R to 40 C.P.R. 50 (relying on Appendix Q, 

which relies on Appendix 0) 

Citations: 40 C.P.R. 50.16(b)/35 Ill. Adm. Code 243.126(b)(2) 

Non-NAAOS Required Monitoring: 

Required by: NCore monitoring for PM10_2_5 

Citation: 40 C.P.R. 58.12(±)(1) 

PRM specified: Appendix 0 to 40 C.P.R. 50 

Citation: Appendix D to 40 C.P.R. 58 (2012), at~ 3(b) 

Summarv re Incorporation of the FRMs, FEMs, and Interpretations. Based on the 

foregoing, the Board has incorporated the three types ofUSEPA-designated monitoring methods 

in the following ways. All of the incorporations have been done by incorporations by reference, 

as described. 

Codified FRMs. The Board has incorporated by reference all of the appendices to 40 

C.P.R. 50 that codify an PRM that is cited in an NAAQS. These appendices set forth the text of 

the method itself. These incorporations by reference directly involve each of the federal 

appendices. See 35 Ill. Adm. Code 243.108. At present, there are eight codified PRMs that 

directly support an NAAQS included in the appendices: Appendices A-1, A-2, C, D, P, G, J, and 

L to 40 C.P.R. 50. 

Non-Codified FRMs. The Board has incorporated by reference the listing of all of the 

non-codified PRMs, but not the PRMs themselves. These methods are identified in the List of 

Designated Methods, but the actual method is not set forth in full. Thus, the Board includes 

these non-codified methods in the Illinois regulations by incorporation by reference to the List of 

Designated Methods. See 35 Ill. Adm. Code 243.108. At present, there are 88 non-codified 

PRMs included in the List of Designated Methods: 16 for PM10, 17 for PM2.5, three for PM10_25, 

nine for ozone, 20 for carbon monoxide, 26 for nitrogen oxides. None are listed for sulfur oxides 

and lead. 

Non-Codified FEMs. The Board has incorporated by reference the listing of all of the 

PEMs, all of which are non-codified. These methods are identified in the List of Designated 

Methods, in the same manner as are the non-codified PRMs, with the actual method not set forth 

in full. As for the non-codified PRMs, the Board includes the PEMs in the Illinois regulations by 

incorporation by reference to the List of Designated Methods. See 35 Ill. Adm. Code 243.108. 

At present, there are 127 PEMs included in the List of Designated Methods: 11 for PM10, 17 for 

PM25, 34 for sulfur oxides, 23 for ozone, five for nitrogen oxides, and 27 for lead. There are 

none for carbon monoxide. 
Interpretations. The Board has incorporated by reference all of the interpretations 

relative to the various NAAQS, all of which are codified as appendices to 40 C.F.R. 50. As for 

the codified FRMs, the Board includes the interpretations in the Illinois regulations by 

incorporation by reference of the various appendices. See 35 Ill. Adm. Code 243 .I 08. At 

present, there are eight interpretations included in the appendices: Appendices H, I, K, N, P, R, 

S, and T to 40 C.F.R. 50. 

The Special-Case FRMs. The Board has incorporated by reference all of the specialcase FRMs that do not directly relate to the NAAQS, all of which are codified as appendices to 

40 C.F.R. 50. As for the codified FRMs that directly support the NAAQS, the Board includes 

the FRMs in the Illinois regulations by incorporation by reference of the various appendices. See 

35 Ill. Adm. Code 243.108. At present, there are three special-case FRMs that do not directly 

support an NAAQS included in the appendices: Appendices B, 0, and Q to 40 C.F.R. 50. 

Omission of Ancillarv Federal Regulations in 40 C.F.R. 53, 58, and 81 

USEPA uses the procedures of 40 C.F.R. 53 to make FRM and FEM designations. See 

40 C.F.R. 53.2, 53.3, and 53.8 (2012). Further, USEPA uses those rules to remove methods from 

the List of Designated Methods. See 40 C.F.R. 53.11 and 53.16 (2012). The Board does not 

read the mandate of Section IO(H) of the Act as requiring adoption of provisions from 40 C.F.R. 

53. While the methods approved by USEPA pursuant to 40 C.F.R. 53 are vital to implementing 

the standards, only the methods themselves are specified within the text of the NAAQS. Since 

no NAAQS directly depends on any provision of 40 C.F.R. 53, the Board has entirely omitted 

the federal methods designations provisions from the illinois NAAQS regulations. 

The requirements of 40 C.F.R. 58 prescribe the requirements for establishing, operating, 

and maintaining monitoring networks and monitoring plans. See 40 C.F.R. 58.2 (2012). While 

these requirements are essential to implementation of the NAAQS, none of the NAAQS tetms 

depend on any provision of the monitoring network rules. Further, as discussed above, the Board 

believes that these requirements are implemented in Illinois as a matter of federal law. Finally, 

USEPA did not cite 42 U.S.C. § 7409 as the basis for adoption of these rules. See 40 C.F.R. 58 

(2012) (authority note); 415 ILCS 5/lO(H), as added by P.A. 97-945, eff. Aug. 10,2012. For 

these reasons, the Board entirely omitted the federal ambient air quality monitoring system 

requirements from the Illinois NAAQS regulations. 

The federal defmitions of air quality monitoring areas and attainment designations of 

these areas are codified in 40 C.F.R. 81. In particular, these federal rules define the boundaries 

of the "air quality control regions" (designated areas) in Illinois. See 40 C.F .R. 81.14 

(Metropolitan Chicago), 81.18 (Metropolitan St. Louis), 81.69 (Paducah-Cairo Interstate), 81.71 

(Rockford-Janesville-Beloit Interstate), 81.98 (Burlington-Keokuk Interstate), 81.1 01 

(Metropolitan Dubuque), 81.1 02 (Metropolitan Quad Cities), 81.262 (North-Central Illinois 

Intrastate), 81.263 (East-Central Illinois Intrastate), 81.264 (West-Central Illinois Intrastate), and 

81.265 (Southeast Illinois Intrastate) (2012). These regulations further codifyUSEPA's 

attainment designations for these designated areas. See 81.314 (2012). 
Many transitional provisions in the federal NAAQS make applicability ofNAAQS 

depend on the attainment status of the vmious designated areas in Illinois. See 40 C.F.R. 50.4(e) 

(2012) (the 1971 NAAQS for sulfur oxides), 50.9(a) (1997 one-hour NAAQS for ozone), 

50.10(c) (1997 24-hourNAAQS for ozone), and 50.12(b) (the 1978 NAAQS for lead) (2102). 

Even though the applicability of these NAAQS directly rely on the federally codified area 

boundaries and attainment designations codified in 40 C.F.R. 81, the Board has not included any 

provision of these ancillmy rules in the Illinois NAAQS rule. 

The Board acknowledges the need to monitor future amendments to 40 C.F.R. 81 to 

dete1mine the applicability ofNAAQS. The Board has used 40 C.F.R. 81 to determine the 

applicability ofNAAQS for two criteria contaminants: the 1971 plimary 24-hour NAAQS for 

sulfur oxides and the 1979 primary calendar qumterly average NAAQS for lead. The Board 

foresees two possible modes for removal of obsolete NAAQS from the Illinois rules. The first is 

US EPA removal of the NAAQS from 40 C.F.R. 50. The second is when the NAAQS no longer 

applies to any area in this State. See 415 ILCS 5/7.2(a)(l) (2012). For this reason, the Board 

will monitor future amendments to 40 C.F.R. 81 with the same vigilance that the Board will use 

with regard to the NAAQS codified in 40 C.F.R. 50. 

Revisions to USEPA Definitions/Definitions Added 

The Board has incorporated the text of the federal definitions into the Illinois NAAQS 

rules. This has involved (I) replacing the former definition-related language of 35 Ill. Adm. 

Code 243.101 with a revised version of the preamble to 40 C.F.R. 50.1; (2) changing the 

meanings of a small number of core definitions to accommodate the context of the Illinois 

regulatory context, adding core definitions as necessary to accommodate those changed 

meanings; (3) revising several of the federal definitions; and ( 4) adding definitions to enhance 

the clality of the rules. The following paragraphs broadly describe the revisions to the federal 

definitions. Table I, details the revisions to the federal language. 

Shifted Meanings and Revisions to the Preamble. The following bulleted segments 

describe the changed meanings for te1ms, the definitions added as a result, and the revisions to 

the preamble statement ofthe definitions provision. 

• The Board changed the meaning of the te1m "Act" to mean the Environmental Protection 

Act (415 ILCS 5 (2012)), rather than the federal Clean Air Act (42 U.S.C. §§ 7401 et seq. 

(2011)). This change required adding a definition of"Clean Air Act," together with a 

defined abbreviation "CAA."9 

The Board shifted the meaning of the te1m "Agency" to mean the Illinois Environmental 

Protection Agency, rather than the U.S. Environmental Protection Agency. This shift 

required adding a definition of the abbreviation "USEPA." 

9 Adding this definition may not have been necessary, as the te1m "CAA" is used only in the 

"Scope" provision of35 Ill. Adm. Code 243.102(a) (derived from 40 C.F.R. 50.2 (2012)), where 

the Board changed "Act" to "CAA" to retain the meaning of the statutory reference. Adding the 

definition of"CAA" maintains greater parity between the State and federal NAAQS rules. 
The Board added an affirmative statement of applicability of the definitions in the 

preamble. No such statement exists in 40 C.F.R. 50.1. Rather, the conesponding federal 

preamble states that the definition of a term given by the Clean Air Act applies to terms 

not defined in 40 C.F.R. 50.1. 

• The Board retained the word "Act" in the language drawn from the federal preamble 

statement in 40 C.F.R. 50.1. The above-described shifted definition of"Act" would 

change the focus fi"om definitions in the federal Clean Air Act to those of the Illinois 

Environmental Protection Act were the Board to retain the word "Act." Since the Board 

perceives that USEP A intended use of the Clean Air Act definitions, the Board has 

replaced "Act" with "CAA" in this statement. The Board fu1ther added a reference to the 

definitions of35 ill. Adm. Code 201.102, which are a segment of the general provisions 

pertinent to the Subtitle B: Air Pollution Control requirements. 

Changes in Defined Terms. The Board has changed a limited number of the defined 

te1ms. The pu!]Joses for the changes are two-fold: (I) to standardize use of the te1m and 

conform the term to its use in the text; and (2) to enhance the clarity of the term. The following 

bulleted points describe the changed tenus: 

The Board changed "exceedance with respect to a national ambient air quality standard" 

to "exceedance of a NAAQS" for enhanced clarity. 

The Board changed "equivalent method" to "federal equivalent method" and added the 

defined abbreviation "FEM" for consistent use in the text of the rules for the reasons 

previously explained in this opinion and order. 

The Board changed "reference method" to "federal reference method" and added the 

defined abbreviation "FRM" for consistent use in the text of the rules for the reasons 

previously explained in this opinion and order. 

Added Defined Terms. The Board has added a limited number of defined terms. The 

purposes for the additions are two-fold: (I) to standardize use of the term in the text of the rules; 

and (2) to enhance the clarity of the text. The following bulleted points describe the added 

defined tenus: 

The Board added a defmition of the term "micrograms per cubic meter" and the defined 

abbreviation "f.!g/m3

" to enable the use of the defmed abbreviation in 35 Ill. Adm. Code 

243.124(c) and 243.126(b)(l) and (b)(2) (co1Tesponding with 40 C.F.R. 50.6(a), 50.7(a), 

and 50.9(a) (2012)), based on the definition of the abbreviation in 40 C.F.R. 50.6(a) and 

50.7(a) (2012). 

The Board added a definition of the te1m "milligrams per cubic meter" and the defmed 

abbreviation "mgfm3

" to enable use of the defined abbreviation in 35 Ill. Adm. Code 

243.124(a)(l) and (a)(2) (based on 40 C.F.R. 50.8(a)(l) and (a)(2) (2012)). 
The Board added a definition of "National Ambient Air Quality Standard" and the 

defined abbreviation "NAAQS" to enable use of the defined abbreviation in multiple 

locations throughout the text of35 Ill. Adm. Code 243. The defmition is based on the 

definition in "Tenns of Environment: Glossary, Abbreviations, and Acronyms" 

(December 1997), EPA 175-B-97-001, at 30. 

• The Board added a definition of the term "pmis per billion" and the defined abbreviation 

"ppb" to enable use of the defined abbreviation in 35 Ill. Adm. Code 243.122(c)(l) and 

(c)(2); 243.124(a), (b), and (e); and appendix C to 35 Ill. Adm. Code 243 (2012) (based 

on 40 C.F.R. 50.15(a) (2012)). 

• The Board added a definition of the te1m "pmis per million" and the defined abbreviation 

"ppm" to enable use of the defined abbreviation in 35 Ill. Adm. Code 243.122(a)(l), 

(a)(2), (b)(l), and (b)(2); 243.123(a)(l), (a)(2), and (d); 243.124(c) and (g); and 

243.125(a)(l), (b)(l), (b)(2), and (c)(2) and Appendix C to 35 Ill. Adm. Code 243 (based 

on40 C.F.R. 50.4(a) and (b), 50.4(a) and (b); 50.8(a)(l), (a)(2), and (d); 50.9(a); 50.10(a) 

and (b); 50.11(g); 50.14(c); and 50.15(b) (2012)), based on the definition of the 

abbreviation in 40 C.F.R. 50.4(a) and (b), 50.8(d),; and 50.17(a) (2012). 

• The Board added a definition of the term "PM10,'' based on the parenthetical definition in 

40 C.F.R. 50.6(c), for the purposes of35 Ill. Adm. Code 243.120(a) (conesponding with 

40 C.F.R. 50.6 (2012)). 

The Board added a defmition of the te1m "PM2.5," based on the parenthetical definition in 

40 C.F.R. 50.7(a), for the purposes of35 Ill. Adm. Code 243.120(b) and (c) 

(conesponding with40 C.F.R. 50.7 and 50.13 (2012)). 

Omitted Defined Terms. The Board has omitted two of the federally defined tenns. 

The purposes for the omissions are (1) to exclude a tenn that has no present operative effect in 

Illinois (see 415 ILCS 5/7.2(a)(l) (2012)); and (2) to omit a term that has been substituted in the 

text of the rules with another term. The following bulleted paragraphs describe the defmitions 

omitted. 

• The Board omitted the federal defmition of "Indian counh-y" from 40 C.F.R. 50.2(i), 

since no such area that falls within this defmition exists in Illinois. 

The Board omitted the defmition of "Administrator," since the te1m "USEP A" is 

substituted for this tenn throughout the text of the rules. See 35 Ill. Adm. Code 243.102 

(definition of"exceptional event"; conesponding with 40 C.F.R. 50.l(j)) and 243.102(b) 

(cmTesponding with 40 C.F.R. 50.2(b)). 

USEPA Rules Added/State Provisions Removed 

The Board removed from the illinois regulations the following provisions that have no 

cunent direct counterparts in the federal rules: 
Preamble (35 Ill. Adm. Code 243.102), which the Board has replaced with the statement 

of scope from 40 C.P.R. 50.2. The recitations of the existing preamble statement are 

similar in nature to those of the federal scope statement. Replacing the State preamble 

statement with the federal stat~ment of scope minimizes the potential for conflicts 

between the Illinois and federal NAAQS requirements. 

Nondegradation (35 Ill. Adm. Code 243.104), which the Board has removed in its 

entirety. The federal rules include no direct counterpart to this requirement. Section II 0 

of the federal Clean Air Act (42 U.S.C. § 7410 (2011)), however, includes a requirement 

that a SIP must not interfere with requirements to prevent significant deterioration 

(PSD). 10 See 42 U.S.C. § 7410(a)(2)(D)(i)(Il) and (a)(2)(J) (2011). 

Monitoring (35 Ill. Adm. Code 243.106), which the Board has removed in its entirety. 

The federal NAAQS rules include no direct counterpart to this requirement. Rather, 40 

C.P.R. 58 sets fmth the detailed requirements for air monitoting networks. As is 

discussed above, the Board has not included requirements from 40 C.P.R. 58 in this 

proceeding. The Board does not perceive those requirements to be part of the NAAQS, 

despite the important role the air monitoting network rules play in ensuring compliance 

with the NAAQS. 

• Rule into Section Table and Section into Rule Table (Appendices A and B to 35 Ill. Adm. 

Code 243), which the Board has removed in their entirety. Those tables cmTelated the 

numbers of the original Illinois air pollution control rules relating to ambient air quality 

with the numbers of rules in the codified version, which arose in 1983. See 7 Ill. Reg. 

13630 (Oct. 14, 1983). The Board sees no present need to maintain those listings. 

The Board added the following provisions: 

• Scope (35 Ill. Adm. Code 243.102), with which the Board replaced the former preamble 

statement, as described immediately above. 

• Air Quality Monitoting Data Influenced by Exceptional Events (35 Ill. Adm. Code 

243.105 and Table A to 35 Ill. Adm. Code 243), which the Board added to CO!Tespond 

with 40 C.P.R. 50.14 (2012) ("Treatment of air quality monitoring data influenced by 

exceptional events"). This provision sets forth the procedure for USEP A approval of 

excluding monitoring data that resulted from an exceptional event. Under the procedure, 

a state flags such data and requests that USEP A exclude that data. Upon an affirmative 

USEP A detetmination that the data were the result of an exceptional event, USEP A will 

exclude that data from the dete1mination of compliance. See 40 C.P.R. 50.14 (2012). 

The procedure also includes a requirement for public notification of an event that is 

expected to result in exceedance ofanyNAAQS. See 40 C.P.R. 50.14(c)(l) (2012). The 

term "exceptional event" is defined in 40 C.P.R. 50.1 Gl as follows: 

10 Part C of the Clean Air Act includes the federal PSD requirements. See 42 U.S.C. § 7470-92 

(2011). 
(j) Exceptional event means an event that affects air quality, is not 

reasonably controllable or preventable, is an event caused by human 

activity that is unlikely to recur at a particular location or a natural event, 

and is detennined by [USEPA] in accordance with 40 CFR 50.14 to be an 

exceptional event. It does not include stagnation of air masses or 

meteorological inversions, a meteorological event involving high 

temperatures or lack of precipitation, or air pollution relating to source 

noncompliance. 40 C.F.R. 50.I(j) (2012); see (35 III. Adm. Code 

243.101); see also 40 C.F.R. 50.l(k) (2012) (definition of"natural event"). 

Incorporating this provision into the Illinois NAAQS regulations required modification of 

the federal text. Principally, the Board modified the language to shift from first-person 

statements of what USEPA will do to third-person statements of what USEPA has said it will do. 

The Board also added topical sub-headings, "exceptional events," "fireworks displays," and 

"prescribed fires" for each of the categories of events considered by USEP A. See 35 III. Adm. 

Code 243.1 05(b )(1 ), (b )(2), and (b )(3). The Board fiuther omitted expired federal provisions. 

See 35 III. Adm. Code243.105(c)(2)(D), (c)(2)(E), (c)(3)(B), and (c)(3)(C). 

Finally, the Board found it necessary to move the tabular material appended to 40 C.F.R. 

50.14(c)(2)(vi) into a separate provision. The tabular material appears in new Table A to 35 III. 

Adm. Code 243. Inclusion of the tabular material at con-esponding with 35 III. Adm. Code 

243. 105(c)(2)(F) would have required a two-inch left indent and extensive reorganization of the 

material. See 1 III. Adm. Code 1 00.340; Illinois Secretary of State, Index Department, 

Administrative Code Division, Style Manual, Illinois Administrative Code and Illinois Register 

(June 2004). 11 

The Board found it necessary to make minor revisions to the federal tabular material. 

First, the Board omitted federal footnotes "a" and "b" relating to federal effective dates from the 

text, since they would serve no function in the Illinois text. Second, the Board corrected the 

2010 one-hour NAAQS for nitrogen oxides from "80-100 PPB, final level TBD" to "100 ppb" 

and the 2010 one-hour NAAQS for sulfur oxides to "75 ppb." 12 The Board added explanation of 

both alterations to the Board note appended to Table A to 35 III. Adm. Code 243. 

Incorporation of the NAAQS for the Six Criteria Pollutants 

In the following paragraphs, the Board considers the current status of the NAAQS 

associated with each of the six priority pollutants for which USEP A has established one or more 

11 Available online at www.cyberdriveillinois.com/publications. 

12 This is an apparent en-or in final federal adoption. Compare 75 Fed. Reg. 35520, 92 (June 22, 

2010) (adopted version) with 74 Fed. Reg. 64810,69-70 (Dec. 8, 2009) (proposed version); see 

75 Fed. Reg. at 35586; 74 Fed. Reg. at 64858 (the table as it appeared in the preamble 

discussions). The 2010 one-hour NAAQS for nitrogen oxides was pending simultaneous with 

the 2010 NAAQS for sulfur oxides. See 75 Fed. Reg. 6474 (Feb. 9, 2010) (adoption of2010 

NAAQS for nitrogen oxides). 
NAAQS: carbon monoxide, lead, nitrogen oxides, ozone, particulate matter, and sulfur oxides. 13 

Each segment of discussion examines the historical development of the NAAQS for the 

particular pollutant, each notes the NAAQS that remain in 40 C.F.R. 50 for that pollutant, and 

each explains the Board's approach to each of the NAAQS. 

Section 243.120: Particulate Matter. USEP A has had three different types of 

standards for particulate matter, which have depended on the size of the particulates to be 

monitored. The initial standard was for total suspended particulates (TSP), which gauged the 

total amount of pm1iculates in the a~nbient air. USEP A then used what has now been called 

"PM10," which are the particulates in air having an aerodynamic diameter of 10 microns or less. 

See 40 C.F.R. 50.6(c) (2012). More recently, USEPA has used "PM25," which is also called 

"fine pm1iculates": those having an aerodynamic diameter of2.5 microns or less. See 40 C.F.R. 

50.7(a) (2012). The following table summmizes the development of the NAAQS for pm1iculate 

matter (indicating curr-ently codified standards in bold): 

1971 Primary Annual Average NAAQS for Total Suspended Particulates (TSP) 

(Removed) 

Standard: 75 f!g/m3 annual geometric mean 

Citation: 40 C.F.R. 50.6(a) (1986) (originally42 C.F.R. 410.6(a) (1971)) 

Aplil30, 1971 (36 Fed. Reg. 8186): 01iginal adoption. 

November 25, 1971 (36 Fed. Reg. 22384): Recodified without substantive 

revision. 

July I, 1987 (52 Fed. Reg. 24634): Removed. 

1971 Primary 24-Hour NAAOS for Total Suspended Pm1iculates CTSPl (Removed) 

Standard: 260 f!g/m3 not to be exceeded more than once in a year 

Citation: 40 C.F.R. 50.6(b) (1986) (originally 42 C.F.R. 41 0.6(b) (1971)) 

Aplil30, 1971 (36 Fed. Reg. 8186): Original adoption. 

November 25, 1971 (36 Fed. Reg. 22384): Recodified without substantive 

reVISIOn. 

July I, 1987 (52 Fed. Reg. 24634): Removed. 

1971 Secondary Annual Average NAAOS for Total Suspended Pm1iculates CTSPl 

(Removed) 

Standard: 60 f!g/m3 used for assessing implementation plans achieving the 1971 

secondary 24-hour standard 

Citation: 40 C.F.R. 50.7(a) (1986) (originally 42 C.F.R. 410.7(a) (1971)) 

Apiil30, 1971 (36 Fed. Reg. 8186): Original adoption. 

13 USEPA adopted primmy and secondaryNAAQS for hydrocarbons in 1971. See 40 C.F.R. 

50.10 (1972); 36 Fed. Reg. 8186 (Apr. 30, 1971) (originally codified as 42 C.F.R. 410.10); see 

also 36 Fed. Reg. 22369, 84 (Nov. 25, 1971) (recodified to 40 C.F.R. 50.10). USEPA removed 

the NAAQS for hydrocarbons in 1982. See 48 Fed. Reg. 628, 29 (January 5, 1983). 
November 25, 1971 (36 Fed. Reg. 22384): Recodified without substantive 

revJsJOn. 

July I, 1987 (52 Fed. Reg. 24634): Removed. 

1971 Secondary 24-Hour NAAQS for Total Suspended Pmticulates CTSP) (Removed) 

Standard: !50 )lg/m3 not to be exceeded more than once in a year 

Citation: 40 C.P.R. 50.7(b) (1986) (originally 42 C.P.R. 410.7(b) (1971)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption. 

November 25, 1971 (36 Fed. Reg. 22384): Recodified without substantive 

revJsJOn. 

July I, 1987 (52 Fed. Reg. 24634): Removed. 

1987 Primarv and Secondarv 24-Honr NAAQS for PM10 (Current) 

Standard: !50 )lg/m3 not to be exceeded more than once per year, on a three-year 

average basis 

Citation: 40 C.P.R. 50.6(a) (2012) 

July I, 1987 (52 Fed. Reg. 24634): Original adoption. 

July 18, 1997 (62 Fed. Reg. 38652): Sunset provision added. 14 

December 22, 2000 (65 Fed. Reg. 80776): Sunset provision removed 15 

1987 Primary and Secondary Annual Average NAAOS for PM10 (Removed) 

Standard: 50 )lg/m3 annual arithmetic mean on a three-year average basis 

Citation: 40 C.P.R. 50.6(b) (2006) 

July I, 1987 (52 Fed. Reg. 24634): Original adoption. 

July 18, 1997 (62 Fed. Reg. 38652): Sunset provision added. 16 

December 22, 2000 (65 Fed. Reg. 80779): Sunset provision removed 17 

October 17,2006 (71 Fed. Reg. 61144): Removed. 

1997 P1imary and Secondary Annual Average NAAQS for PM10 (Removed) 

Standard: 50 [Lglm3 annual arithmetic mean, averaged over three years 

Citation: 40 C.P.R. 50.7(a)(2) (1998) 

14 Not described in this surnn1ary outline because USEPA subsequently removed the sunset 

provision. See 40 C.P.R. 50.6(d) (1998) (the removed sunset provision). 

15 As a result of the decision in American Trucking Assoc. v. EPA, 175 F. 2d 1027, modified en 

bane, 195 F.3d 4 (D.C. Cir. 1999), aff'd in part and rev 'din part sub nom Whitman v. Ame1ican 

Trucking Assoc., 531 U.S. 457,121 S. Ct. 903,149 L. Ed. 2d 69 (2001), on remand, 283 F.3d 

355 (D.C. Cir. 2002). 

16 See supra note 14. 

17 See supra note 15. 
July 18, 1997 (62 Fed. Reg. 38652): Original adoption. 

July 30, 2004 (69 Fed. Reg. 45592): Removed. 

1997 Primary and Secondary 24-Hour NAAQS for PM10 (Removed) 

Standard: 150 [.tg/m3 99th percentile, averaged over tlu·ee years 

Citation: 40 C.P.R. 50.7(a)(2) (1998) 

July 18, 1997 (62 Fed. Reg. 38652): Original adoption. 

July 30, 2004 (69 Fed. Reg. 45592): Removed. 

1997 Primarv and Secondarv Annnal Average NAAOS for PM,.s (Current) 

Standard: 15.0 [.tg/m3 arithmetic mean, averaged over three years 

Citation: 40 C.P.R. 50.7(a) (2012) (originally40 C.P.R. 50.7(a)(l) (1998)) 

July 18, 1997 (62 Fed. Reg. 38652): Original adoption. 

July 30, 2004 (69 Fed. Reg. 45592): Renumbered to subsection (a). 

1997 Primarv and Secondarv 24-Hour NAAQS for PM, 5 (Current) 

Standard: 65 [.tg/m3 98th percentile, averaged over three years 

Citation: 40 C.P.R. 50.7(a) (20 12) (originally 40 C.P.R. 50. 7(a)(l) (1998)) 

July 18, 1997 (62 Fed. Reg. 38652): Original adoption. 

July 30, 2004 (69 Fed. Reg. 45592): Renumbered to subsection (a). 

2006 Primarv and Secondarv Annual Average NAAQS for PM,.s (Current) 

Standard: 15.0 [.tg/m3 arithmetic mean, averaged over three years 

Citation: 40 C.P.R. 50.13(a) (2012) 

October 17, 2006 (71 Fed. Reg. 61144): Original adoption. 

2006 Primarv and Secondarv 24-Hour NAAQS for PM, 5 (Current) 

Standard: 35 [.tg/m3 98th percentile, averaged over tlu·ee years 

Citation: 40 C.P.R. 50.13(a) (2012) 

October 17, 2006 (71 Fed. Reg. 61144): Original adoption. 

Five primary and secondary NAAQS for particulate matter remain codified in tiu·ee 

federalmles: 40 C.P.R. 50.6, 50.7, and 50.13. There remains one standard for PM10 and four for 

PM25 .

18 The Board has codified these five standards in 35 Ill. Adm. Code 243.120. The Board 

has replaced this patiiculate matter provision with the text of the five federal NAAQS. Each of 

18 USEPA proposed and declined to adopt a standard for coarse particulate matter (PM10•2.5). See 

the discussion that appears at page 20 of this opinion and order. 
the federal pmticulate matter provisions appears in a separate subsection, one for each of the 

1987, 1997, and 2006 standards. The five NAAQS are codified as follows: 

Subsection Federal Citation NAAQS 

243.120(a) 40 C.F.R. 50.6 1987 primary and secondary 24-hour NAAQS for PM10 

1997 primary and secondary annual average NAAQS for 

243.120(b) 40 C.F.R. 50.7 PM2.s 

1997 primary and secondary 24-hour NAAQS for PM2.5 

2006 primary and secondary annual average NAAQS for 

243.120(c) 40 C.F.R. 50.13 PM2.5 

2006 primmy and secondary 24-hour NAAQS for PM2.5 

The Board does not engage in substantive review of federal standards in the context of an 

identical-in-substance proceeding, except as necessary to incmporate them into the illinois air 

regulations. Persons wishing to understand the substance of a federal standard should review the 

Federal Register notices by which US EPA has adopted, reviewed, and amended the various 

standards. Those notices are listed in the foregoing review of the federal standards for 

particulate matter. 

The Board has codified the federal NAAQS for pmticulate matter without substantive 

revision. All of the deviations fi·om the literal text of the federal NAAQS are itemized in Table 

1. The Board discusses here one addition to the federal text: the addition of explanation in the 

Board notes to the 1987 and 1997 standards. 

The explanation appended to the 1987 NAAQS for PM10 outlines how USEPA added a 

sunset clause to the 1987 PM10 standards when adopting a revised 1997 standard for PM10 and 

the 1997 NAAQS for PM2.5• See 62 Fed. Reg. 38652, 701 (July 18, 1997). The sunset provision 

stated that the 1987 standards would not apply to an area designated non-attainment with the 

1987 standards once USEPA has established rules for non-attainment areas as required by 

section 172(e) of the Clean Air Act (42 U.S.C. § 7502(e) (2011). The sunset provision further 

stated that the 1987 standards would not apply to an area that had attained those standards after 

US EPA has approved a SIP for that area relative to the new 1997 standards. See 40 C.F.R. 

50.6(d) (1998). 

USEPA later removed the 1997 NAAQS for PM10 and the sunset provision from the 1987 

standard as a result of decision in American Trucking Assoc. v. EPA, 17 5 F. 2d 1 027, modified 

en bane, 195 F.3d 4 (D.C. Cir. 1999), aff'd in part and rev'd in part, sub nom Whitman v. 

American Trucking Assoc., 531 U.S. 457, 121 S. Ct. 903, 149 L. Ed. 2d 69 (2001), on remand, 

283 F.3d 355 (D.C. Cir. 2002). See 69 Fed. Reg. 45592 (July 30, 2004); 65 Fed. Reg. 80776, 77 
(Dec. 22, 2000). As a result, the 1987 plimary and secondary 24-hour NAAQS for PM10 

continues to apply. 19 See 65 Fed. Reg. 80776, 77 (Dec. 22, 2000). 

The Board has included the 1987 standard for PM10 . The explanation that the Board 

appended to the 1987 standards explains Board retention of the 1987 standards. The Board has 

not included the 1997 NAAQS for PM10 in the Illinois regulations. 

The Board has retained the 1997 NAAQS for PM2.

5 because USEPA has done so. The 

2006 ptimary and secondary annual average NAAQS for PM2.s is nearly the same as the 1997 

annual average standard. 20 On the other hand, the 2006 prin1ary and secondary 24-hour NAAQS 

for PM2.s is more stringent than the 1997 24-hour standard. Compare 40 C.P.R. 50.7(a) (2012) 

(1997 standard) with 40 C.P.R. 50.13 (2012) (2006 standard); see 71 Fed. Reg. 61144,45, 64 

(Oct. 17, 2006). Further, it appears that the 1997 standards for PM2.s may have continuing 

vitality for implementation of various federal ambient air quality mles. See 71 Fed. Reg. 61144, 

49 (Oct. 17, 2006). The explanation appended to the 1997 NAAQS for PM2.5 outlines USEPA's 

addition of the 2006 annual average and 24-hour NAAQS for PM2_5 and Board retention of the 

1997 standard. 

Section 243.122: Sulfur Oxides. USEP A has maintained primary and secondary 

NAAQS for sulfur oxides since 1971. The following table summarizes the development of the 

NAAQS for sulfur oxides (indicating currently codified standards in bold): 

1971 Primarv Annual Average NAAOS for Sulfur Oxides (as SO,) (Subject to 

Sunset) 

Standard: 

Citation: 

0.030 ppm annual arithmetic mean 

40 C.P.R. 50.4(a) (20 12) (originally 42 C.F.R. 41 0.4(a) (1971 )) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 80 J.tg/m3 (0.03 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

reVISIOn. 

April21, 1993 (58 Fed. Reg. 21351): Retained without revision. 

May 22, 1996 (61 Fed. Reg. 25566): Immaterial change to 0.030 ppm (significant 

digit added, metric units removed). 

June 22,2010 (75 Fed. Reg. 35520): Sunset provision added: the standard does 

not apply to an area one year after USEPA designation of the 

attainment status of that area under the 2010 primary one-hour 

standard, with exceptions. 

1971 Primarv 24-Hour NAAOS for Sulfur Oxides (as S02) (Subject to Sunset) 

Standard: 0.14 ppm not to be exceeded more than once per year 

19 USEPA retained the 24-hour 1987 NAAQS and removed the annual average 1987 NAAQS in 

2006. See 71 Fed. Reg. 61144 (Oct. 17, 2006). 

20 USEP A kept the numerical standard the same, but revised the monitoring and data handling 

conventions for detennining compliance. See 71 Fed. Reg. 61144, 77, 210-11 (Oct. 17, 2006). 
Citation: 40 C.F.R. 50.4(b) (2012) (originally42 C.F.R. 4!0.4(b) (1971)) 

April 30, 1971 (36 Fed. Reg. 8186): Original adoption as 365 !lg/m3 (0.14 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

reVISIOn. 

Ap1il 21,1993 (58 Fed. Reg. 21351): Retained without revision. 

May 22, 1996 (61 Fed. Reg. 25566): Immaterial change to 0.14 ppm (metJ.ic units 

removed). 

June 22, 2010 (75 Fed. Reg. 35520): Sunset provision added: the standard does 

not apply to an area one year after USEP A designation of the 

attainment status of that area under the 2010 primary one-hour 

standard, with exceptions. 

1971 Secondary Annual Average NAAQS for Sulfur Oxides (as SO,) (Revoked) 

Standard: 60 !lg/m3 (0.02 ppm) annual mithmetic mean 

Citation: 40 C.F.R. 50.5(a) (1972) (originally 42 C.F.R. 4!0.5(a) (1971)) 

April 30, 1971 (36 Fed. Reg. 8186): Original adoption. 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

revJsJOn. 

September 14, 1973 (36 Fed. Reg. 25678): Revoked. 

1971 Secondary 24-Hour NAAQS for Sulfur Oxides (as SO,) (Revoked) 

Standard: 260 !lg/m3 (0.1 ppm) not to be exceeded more than once per year 

Citation: 40 C.P.R. 50.5(b) (1972) (originally 42 C.F.R. 4!0.5(b) (1971)) 

April 30, 1971 (36 Fed. Reg. 8186): Original adoption. 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

reVISIOn. 

September 14, 1973 (36 Fed. Reg. 25678): Revoked. 

1971 Secondarv Three-Hour NAAOS for Sulfur Oxides (as S02) (Current) 

Standard: 0.5 ppm not to be exceeded more than once per year 

Citation: 40 C.F.R. 50.5 (2012) (originally 42 C.F.R. 410.5(c) (1971), then 40 

C.P.R. 50.5(c) (1972)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 1300 !lg/m3 (0.5 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

revision. 

September 14, 1973 (36 Fed. Reg. 25678): Renumbered. 

May 22, 1996 (61 Fed. Reg. 25566): Immaterial change to 0.5 ppm (metric units 

removed). 

2010 Primarv One-Hour NAAOS for Sulfur Oxides (as SO,) (Current) 

Standard: 7 5 ppb 99th percentile, averaged over three years 

Citation: 40 C.F.R. 50.17(a) (2012) (originally 42 C.F.R. 410.4(a) (1971)) 
June 22,2010 (75 Fed. Reg. 35520): Original adoption. 

Three primary and one secondary NAAQS for sulfur oxides remain codified in three 

federalmles: 40 C.F.R. 50.4, 50.5, and 50.17. The Board has codified these four standards in 35 

Ill. Adm. Code 243.122. The Board has replaced the existing sulfur oxides provision with the 

text of the federal NAAQS. Each of the federal sulfur oxides provisions appears in a separate 

subsection. The four NAAQS for sulfur oxides are codified as follows: 

Subsection Federal Citation NAAQS 

243.122(a)(1) 40 C.F.R. 50.4(a) 1971 primary annual average NAAQS for sulfur oxides 

243.122(a)(2) 40 C.F.R. 50.4(b) 1971 primary 24-hour NAAQS for sulfur oxides 

243.122(b) 40 C.F.R. 50.5 1971 secondary three-hour NAAQS for sulfur oxides 

243.122(c) 40 C.F.R. 50.17 2010 primmy one-hour NAAQS for sulfur oxides 

As previously discussed, the Board does not engage in substantive review of federal 

standm·ds in the context of an identical-in-substance proceeding, except as necessary to 

incorporate them into the illinois air regulations. Persons wishing to understand the substance of 

a federal standard should review the Federal Register notices by which US EPA has adopted, 

reviewed, and amended the various standards. Those notices are listed in the foregoing review 

of the federal standards for sulfur oxides. 

The Board has codified the federal NAAQS for sulfur oxides without substantive 

revision. All of the deviations from the literal text of the federal NAAQS are itemized in Table 

1. The Board discusses here only one issue relative to the federal NAAQS for sulfur oxides: 

USEPA addition of a sunset provision to the 1971 primary annual average and 24-hourNAAQS 

for sulfur oxides with adoption of the 2010 primary NAAQS for sulfur oxides. 

Sunset Clause (or the 1971 Primary 24-Hour NAAOS (or Sulfur Oxides. Upon 

adoption of the 2010 primmy one-hour NAAQS for sulfur oxides, USEP A added the following 

sunset clause: 

The [ 1971 primmy annual average and 24-hour] standards [for sulfur oxides] set 

fmth in this section will remain applicable to all areas notwithstanding the 

promulgation of[the 2010] so2 [primary] national ambient air quality standards 

(NAAQS) [for sulfur oxides] in§ 50.17. The [1971 primary annual average and 

24-hour] S02 NAAQS set forth in this section will no longer apply to an area one 

year after the effective date of the designation of that area, pursuant to section 107 

of the Clean Air Act, for the [201 0] S02 NAAQS set forth in§ 50.17; except that 

for areas designated nonattainment for the [ 1971 primary annual average and 24-

hour] S02 NAAQS set forth in this section as of the effective date of§ 50.17, and 

areas not meeting the requirements of a SIP call with respect to requirements for 
the [1971 primary annual average and 24-hour] S02 NAAQS set forth in this 

section, the [1971 primary annual average and 24-hour] S02 NAAQS set forth in 

this section will apply until that area submits, pursuant to section 191 of the Clean 

Air Act [42 U.S.C. § 7514], and EPA approves, an implementation plan providing 

for attaimnent of the [2010] S02 NAAQS set forth in§ 50.17. 40 C.F.R. 50.4(e) 

(2012); 75 Fed. Reg. 35520, 92 (June 22, 2010). 

The Board sees various altematives for codifying tllis provision. One basic change would 

apply to all of the altematives: changing "the effective date of§ 50.17" to "August 23, 2010." 

See 75 Fed. Reg. 35520 (June 22, 2010). Application of other segments of this sunset provision 

to areas of Illinois is more problematic. 

The Board cannot defnlitively determine whether the 1971 primary annual average and 

24-hour NAAQS for sulfur oxides apply to any area of the State. Although the federal 

regulations make it clear that USEP A had not designated any area in Illinois as non-attaimnent as 

of August 23, 2010 (see 40 CFR 81.314 (201 0)), the federal regulations do not make it clear that 

no area was "not meeting the requirements of a SIP call with respect to requirements for the 

[1971 primary annual average and 24-hour] S02 NAAQS" as of that date (see 40 C.F.R. 52.720, 

52,722, and 52.724 (20 12)). The Board was able to determine that USEP A had not made any 

attaimnent detenninations with regard to the 2010 primary one-hour NAAQS for sulfur oxides as 

of December 31, 2012. See 40 C.F.R 81.314 (2012); List of Sections Affected (December 2012), 

at 82; 77 Fed. Reg. 48062, 71 (Aug. 13, 2012) (pertaining only to ozone). It is apparent, 

however, that the Agency has recommended area designations for Illinois to USEP A. See letter 

of June 2, 2011 from Laurel Kroack, Chief, Bureau of Air, Agency, to Che1yl A. Newton, 

Director, Office of the Air and Radiation Division, USEP A Region 5 (available at 

http:/ /www.epa.gov/so2designations/recletters/R5 _ IL _rec _ wtechanalysis. pdf). 

After US EPA has made area designations under the 2010 one-hour NAAQS for sulfur 

oxides for each area of Illinois, and after USEPA has approved an implementation plan for 

attaimnent for each area of Illinois, the 1971 primary NAAQS for sulfur oxides will become 

obsolete as to Illinois. Until that time, the Board must maintain a provision to conespond with 

the sunset provision of 40 C.F.R. 50.4(e) at 35 Ill. Adm. Code 243.122(a)(5). The Board outlines 

five options and selects one in the following paragraphs. 

Option 1: Retain the Entire Federal Text with Minimal Deviation. The first option is 

for the Board to retain the entire text of 40 C.F.R. 50.4( e) with minimal deviation. In addition to 

the routine clarifying revisions, this altemative reorganizes the material by moving the two 

exception statements of areas where the 1971 p1imary annual average and 24-hour NAAQS will 

continue to apply into subsidiary subsections. This first option would add an explanatmy Board 

note to the text. This first option would appear as follows: 

5) The 1971 primary annual average and 24-hour NAAQS for sulfur oxides set fmth 

in this subsection (a) remain applicable to all areas notwithstanding the 

promulgation of the 2010 primary one-hour NAAQS for sulfur oxides in 

subsection (c) of this Section. The 1971 primary annual average and 24-hour 

NAAQS for sulfur oxides set forth in this subsection (a) will no longer apply to an 
area one year after the effective date of the designation of that area by USEPA 

pursuant to 42 USC 7407 for the 2010 primary one-hour NAAQS for sulfur 

oxides set fm1h in subsection (c) of this Section; except that the 1971 primary 

annual average and 24-hour NAAQS for sulfur oxides set forth in this subsection 

(a) will apply until USEPA has approved an implementation plan for that area 

pursuant to 42 USC 7514 for attainment of the 2010 primary one-hour NAAQS 

for sulfur oxides set fm1h in subsection (c) of this Section for the following areas: 

A) Areas that USEPA has designated nonattainment for the 1971 primary 

annual average and 24-hour NAAQS for sulfur oxides set forth in this 

subsection (a) as of August 23, 2010; and 

B) Areas that had not met the requirements ofUSEPA a SIP call with respect 

to requirements for the 1971 primary annual average and 24-hour NAAQS 

for sulfur oxides set fm1h in this subsection (a). 

BOARD NOTE: The Board substituted "August 23, 20 I 0" for the open-ended 

language in corresponding 40 CFR 50.4(e) relative to the effective date of 40 CFR 

50.17. August 23,2010 is the effective date recited at 75 Fed. Reg. 35520 (June 

22, 201 0). The Agency recommended that USEP A designate limited areas of 

Illinois as non-attainment with the 2010 p1imary one-hour NAAQS for sulfur 

oxides. See letter of June 2, 2011 from Laurel Kroack, Chief, Bureau of Air, 

Agency, to Cheryl A. Newton, Director, Office of the Air and Radiation Division, 

USEPA Region 5 (available at http://www.epa.gov/so2designations/recletters/ 

R5 _IL _rec _ wtechanalysis.pdf). USEP A had not designated any area of Illinois 

for the 2010 primary one-hour NAAQS for sulfur oxides as of December 31, 

2012. See 40 CFR 81.314 (area designations in Illinois). When the conditions of 

this subsection (a)(5) have been fulfilled, or USEPA has removed 40 CFR 50.4, 

the Board will remove the standard of this subsection (a) as obsolete. 

Option 2: Replace the Statement o(lnapplicabilitv and Delete One Exception 

Statement The second option is for the Board to retain the text of 40 C.F.R. 50.4(e) that states 

the continued applicability of the 1971 primary annual average and 24-hour NAAQS for sulfur 

oxides. This option, however, would replace the two conditional statements. First, a statement 

that the Board will remove the 1971 NAAQS when the conditions of 40 C.F.R. 50.4(e) have 

been fulfilled would replace the federal statement when the 1971 primary NAAQS will no longer 

apply. Second, this option would delete the exception statement relative to areas designated as 

non-attainment with the 1971 standards. This second option would add the same explanatory 

Board note to the text as would the first option. This second option would appear as follows 

(with the Board note omitted): 

5) The 1971 primary annual average and 24-hour NAAQS for sulfur oxides set forth 

in this subsection (a) remains applicable to all areas notwithstanding the 

promulgation of the 2010 primary NAAQS for sulfur oxides in subsection (c) of 

this Section. The Board will delete the 1971 primary annual average and 24-hour 

NAAQS for sulfur oxides set fm1h in this subsection (a) after fulfillment of the 
conditions recited by USEP A in con·esponding 40 CFR 50.4( e) pursuant to 42 

USC 7407 for the 2010 primary one-hour NAAQS for sulfur oxides set fmth in 

subsection (c) of this Section; except that the 1971 ptimmy annual average and 

24-hour NAAQS for sulfur oxides set forth in this subsection (a) will apply until 

USEP A has approved an implementation plan for that area pursuant to 42 USC 

7514 for attainment of the 2010 primary one-hour NAAQS for sulfur oxides set 

forth in subsection (c) of this Section. 

Option 3: Replace the Statement o(lnapplicabilitv with a Statement That the Board 

Will Remove the 1971 NAAOS When Conditions Are Fulfilled. The third option is for the 

Board to replace the text of 40 C.F.R. 50.4(e) with a statement that Board will remove the 1971 

primm·y annual average and 24-hour NAAQS for sulfur oxides after fulfillment of the conditions 

recited in 40 C.F.R. 50.4(e). This option would describe when the 1971 NAAQS no longer 

apply and the two associated conditional statements in an appended Board note. This third 

option would appear as follows: 

5) The 1971 primary annual average and 24-hour NAAQS for sulfur oxides set forth · 

in this subsection (a) remains applicable to all areas notwithstanding the 

promulgation of the 2010 primary one-hour NAAQS for sulfur oxides in 

subsection (c) of this Section. The Board will delete the 1971 primary annual 

average and 24-hour NAAQS for sulfur oxides set fmth in this subsection (a) after 

fulfillment of the conditions recited by USEP A in con-esponding 40 CFR 50.4( e). 

BOARD NOTE: Con-esponding 40 CFR 50.4(e) recites that the 1971 primary 

NAAQS for sulfur oxides remains effective in two types of areas for which 

USEP A has not yet approved an implementation plan for attainment with the 

2010 primary one-hour NAAQS for sulfur oxides. The first type of area is one 

that USEP A had designated as non-attainment for that standard as of the effective 

date of the 2010 primary one-hour NAAQS for the 1971 primaryNAAQS for 

sulfur oxides as of the effective date of the 2010 NAAQS. That date was August 

23,2010. See 75 Fed. Reg. 35520 (June 22, 2010). As ofthat date, USEPA had 

not designated any area in Illinois as non-attaimnent. See 40 CFR 81.314 (2010). 

The Board is unaware of any USEPA SIP call for any area of Illinois relative to 

the 1971 primaryNAAQS for sulfur oxides. As of December 31, 2012, USEPA 

had not yet designated the attainment status of areas in Illinois. See 40 CFR 

81.314 (2012). The Agency recommended that USEPA designate limited areas of 

Illinois as non-attaimnent with the 2010 ptimary one-hour NAAQS. See letter of 

June 2, 2011 from Laurel Kroack, Chief, Bureau of Air, Agency, to Cheryl A. 

Newton, Director, Office of the Air and Radiation Division, USEP A Region 5 

(available at http://www.epa.gov/so2designations/recletters/ 

R5_IL_rec_wtechanalysis.pdf). When the conditions of this subsection (a)(5) 

have been fulfilled, or USEP A has removed 40 CFR 50.4, the Board will remove 

the standard of this subsection (a) as obsolete. 

Option 4: Replace the Statement o(lnapplicabilitv with a Statement That the Board 

Will Remove the 1971 NAAOS When USEPA Makes Area Designations Under the 2010 One 
Hour NAAQS or Removes the 1971 NAAQS. The fourth option is a variation of the third 

option. This fomth option is for the Board to replace the text of 40 C.F.R. 50.4(e) with a 

statement that Board will remove the I 971 p1imary annual average and 24-hour NAAQS for 

sulfur oxides after USEP A has made areas designations for all areas in Illinois under the 20 I 0 

primary one-hour NAAQS for sulfur oxides or after USEP A has removed the standard of 40 

C.F.R. 50.4. This option would describe when the 1971 NAAQS no longer apply and the two 

associated conditional statements in an appended Board note. This second option would add the 

same explanatory Board note to the text as would the third option. This fourth option would 

appear as follows (with the Board note omitted): 

5) The 1971 p1imary annual average and 24-hour NAAQS for sulfur oxides set fmth 

in this subsection (a) remain applicable to all areas notwithstanding the 

promulgation of the 2010 primary one-hour NAAQS for sulfur oxides in 

subsection (c) of this Section. The Board will delete the 1971 primmy annual 

average and 24-hour NAAQS for sulfur oxides set forth in this subsection (a) after 

USEP A has made attainment designations with regard to all areas in Illinois under 

the 20 I 0 primary one-hour NAAQS for sulfur oxides or US EPA has removed the 

existing standard of 40 CFR 50.4. 

Option 5: Remove the Sunset Provision in Its Entiretv. The fifth option would involve 

removing the sunset clause in its entirety. The sunset provision operates to eclipse the 1971 

primary NAAQS as a matter of federal law. When it is clear that all of the conditions have been 

fulfilled, or ifUSEPA removes 40 C.F.R. 50.4, the Board can simply remove 35 III. Adm. Code 

243.122(a). The omission of the sunset clause in its entirety does not affect the fact that Board 

removal of subsection (a) will be required to remove the 1971 prima1y annual average and 24-

hour NAAQS from the Illinois regulations. 

Selection of Option 3. The Board has adopted the third option described above and 

replaces the conditioned statement of inapplicability of 40 C.F.R. 50.4(e) with a statement that 

the Board will remove the 1971 primary NAAQS after fulfillment of the federal conditions. 

Option 3 preserves the statement of applicability. Option 3 is consistent with the Board's 

identical-in-substance mlemaking practice to maintain a provision until the Board removes it. 

Option 3 avoids the convoluted conditional statement and its exceptions. Whether the conditions 

are fulfilled is best determined between USEPA and the Agency. 

The Board has requested that the Agency infom1 the Board in the future should USEP A 

detennine that the 1971 prin1aryNAAQS for sulfur oxides do not apply to any area of Illinois. 

The Agency stated at hearing that the USEP A area designations are now overdue. Tr. at 10-11. 

The Board can list areas of inapplicability in future updates to the NAAQS and ultimately 

remove 35 III. Adm. Code 243.122(a) when the 1971 Standards no longer apply to any area of 

the State. 

Section 243.123: Carbon Monoxide. USEPA adopted primary and secondary NAAQS 

for sulfur oxides in 1971. See 36 Fed. Reg. 8186 (Apr. 30, 1971). Each of the primary and 

secondary NAAQS included two standards: an eight-hour standard and a 24-hour standard. 
Today, only the primary standards remain. The evolution of the federal NAAQS for carbon 

monoxide is outlined as follows (indicating the cmTently codified standards in bold): 

1971 Primarv Eight-Hour NAAf!S for Carbon Monoxide (Current) 

Standard: 9 ppm (I 0 mg/m) not to be exceeded more than once per year 

Citation: 40 C.P.R. 50.8(a)(l) (2012) (01iginally 42 C.P.R. 410.8(a) (1971), then 

40 C.P.R. 50.8(a) (1972)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 10 mg/m3 (9 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 22384): Recodified without substantive 

reVISIOn. 

February 18, 1975 (40 Fed. Reg. 7042): Amended to require the use of federally 

approved monitoring methods (FRMs and FEMs). 

September 13, 1985 (50 Fed. Reg. 37484): Immaterial change to 9 ppm (10 

11g/m3), renumbered to subsection (a)(!). 

August I, 1994 (59 Fed. Reg. 38906): Retained without revision. 

August 31, 20 II (76 Fed. Reg. 54294): Retained without revision. 

1971 Secondary Eight-Hour NAAOS for Carbon Monoxide (Revoked) 

Standard: 9 ppm (I 0 mg/m3

) not to be exceeded more than once per year 

Citation: 40 C.P.R. 50.8(a) (1985) (01iginally 42 C.P.R. 410.8(a) (1971)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 40 mg/m3 (35 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

revision. 

February 18, 1975 (40 Fed. Reg. 7042): Amended to require the use of federally 

approved monitoring methods (FRMs and FEMs). 

September 13, 1985 (50 Fed. Reg. 37484): Revoked. 

1971 Primarv One-Hour NAAQS for Carbon Monoxide (Current) 

Standard: 35 ppm (40 mg/m3) not to be exceeded more than once per year 

Citation: 40 C.P.R. 50.8(a)(2) (2012) (originally42 C.P.R. 410.8(b) (1971), then 

40 C.P.R. 50.8(b) (1972)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 10 mg/m3 (9 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 22384): Recodified without substantive 

reVISIOn. 

February 18, 1975 (40 Fed. Reg. 7042): Amended to require the use of federally 

approved monitoring methods (FRMs and FEMs). 

September 13, 1985 (50 Fed. Reg. 37484): Immaterial change to 9 ppm (I 0 

11g/m3), renumbered to subsection (a)(2). 

August I, 1994 (59 Fed. Reg. 38906): Retained without revision. 

August 31, 20!1 (76 Fed. Reg. 54294): Retained without revision. 

1971 Secondary One-Hour NAAQS for Carbon Monoxide (Revoked) 

Standard: 35 ppm ( 40 mg/m3

) not to be exceeded more than once per year 
Citation: 40 C.F.R. 50.8(b) (2012) (originally 42 C.F.R. 410.8(b) (1971)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 40 mg/m3 (35 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 22384): Recodified without substantive 

rev1s10n. 

February 18, 1975 (40 Fed. Reg. 7042): Amended to require the use of federally 

approved monitoring methods (FRMs and FEMs). 

September 13, 1985 (50 Fed. Reg. 37484): Revoked. 

Two primary NAAQS for carbon monoxide remain codified in one federal regulation: 40 

C.F.R. 50.8. These are a one-hour NAAQS and an eight-hour NAAQS. The Board has codified 

the two standards in 35 Ill. Adm. Code 243.123. The Board has replaced the existing provision 

relative to carbon monoxide with the text of the federal NAAQS. The single federal provision 

relative to carbon monoxide appears in a single subsection of the Illinois rules. The two NAAQS 

are codified as follows: 

Subsection 

243.123(a)(l) 

243.123(b)(2) 

Federal Citation 

40 C.F.R. 50.8(a)(l) 

40 C.F.R. 50.8(a)(2) 

NAAQS 

1971 primary eight-hour NAAQS for carbon 

monoxide 

1971 primaryone-hourNAAQS for carbon 

monoxide 

The Board does not engage in substantive review of federal standards in the context of an 

identical-in-substance proceeding, except as necessary to incorporate them into the Illinois air 

regulations. Persons wishing to understand the substance of a federal standard should review the 

Federal Register notices by which USEP A has adopted, reviewed, and amended the various 

standards. Those notices are listed in the foregoing review of the federal standards for carbon 

monoxide in the initial pmtion of this discussion. 

The Board has codified the federal NAAQS for carbon monoxide without substantive 

rev1s10n. All of the deviations from the literal text of the federal NAAQS are itemized in Table 

1. 

Section 243.124: Nitrogen Oxides. USEP A adopted primary and secondary annual 

average NAAQS for nitrogen oxides in 1971. See 36 Fed. Reg. 46246 (Oct. 5, 1978). USEPA 

recently adopted a 2010 primary one-hour NAAQS for nitrogen oxides. The evolution of the 

NAAQS for nitrogen oxides was as follows (indicating all of the standards as cmTently codified 

in bold): 

1971 Primarv Annual Average NAAf?S for Nitrogen Oxides (as N02) (Current) 

Standard: 0.053 ppm (I 00 [J.g/m ) annual arithmetic mean 

Citation: 40 C.F.R. 50.ll(a) (2012) (originally 42 C.F.R. 410.11 (1971)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 100 [J.g/m3 (0.05 ppm). 
November 25, 1971 (36 Fed. Reg. 22369, 22384): Recodified without substantive 

revision. 

June 19, 1985 (50 Fed. Reg. 25532): Changed to a separate primary NAAQS and 

renumbered subsection (a) with immaterial change to 0.053 ppm 

(100 flg/m3

) (significant digit added, metric and non-metric units 

switched). 

October 8, 1996 (61 Fed. Reg. 52852): Retained without revision. 

Febmary 9, 2010 (75 Fed. Reg. 6474): Retained with immaterial change to 53 

ppb (units changed, metric units removed). 

1971 Secondarv Annual Average NAAQS for Nitrogen Oxides (as N01) (Current) 

Standard: 0.053 ppm (1 00 flg/m3) annual arithmetic mean 

Citation: 40 C.P.R. 50.11(c) (2012) (originally42 C.P.R. 410.11 (1971), then40 

C.P.R. 50.11 (1972) and 40 C.P.R. 50.ll(b) (1985)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as a primary and 

secondaryNAAQS of100 flg/m3 (0.05 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

reVISIOn. 

June 19, 1985 (50 Fed. Reg. 25532): Changed to a separate secondary NAAQS 

and renumbered subsection (b) with immaterial change to 0.053 

ppm (1 00 f!g/m3

) (significant digit added, metric and non-metric 

units switched). 

October 8, 1996 (61 Fed. Reg. 52852): Retained without revision. 

Febmary 9, 2010 (75 Fed. Reg. 6474): Retained without revision; renumbered 

subsection (c). 

2010 Primarv One-Hour NAAQS for Nitrogen Oxides (as NOz) (Current) 

Standard: 100 ppb three-year average of the annual 98th percentile of the daily 

maximum one-hour average concentration 

Citation: 40 C.P.R. 50.11(b) (2012) 

Febmary 9, 2010 (75 Fed. Reg. 6474): Original adoption. 

Two primary and one secondary NAAQS for nitrogen oxides are codified in one federal 

mle: 40 C.P.R. 50.11. The Board has codified the two 1971 standards in 35 Ill. Adm. Code 

243.124. The Board has replaced the existing provision with the text of the three federal 

NAAQS, adding the 2010 primary 24-hour NAAQS for nitrogen oxides to the text. Each of the 

federal provisions relative to nitrogen oxides appears in a separate subsection, with the 

subsection for each of the standards. The three NAAQS for nitrogen oxides are codified as 

follows: 

Subsection Federal Citation NAAQS 

243.124(a) 40 C.P.R. 50.1l(a) 1971 primary annual average NAAQS for nitrogen oxides 
243.124(b) 40 C.P.R. 50.ll(b) 

243.124(c) 40 C.P.R. 50.5 

2010 primary 24-hour NAAQS for nitrogen oxides 

1971 secondary annual average NAAQS for nitrogen 

oxides 

The Board does not engage in substantive review of federal standards in the context of an 

identical-in-substance proceeding, except as necessary to incorporate them into the Illinois air 

regulations. Persons wishing to understand the substance of a federal standard should review the 

Federal Register notices by which USEPA has adopted, reviewed, and amended the various 

standards. Those notices are listed in the foregoing review of the federal standards for nitrogen 

oxides in the initial pmtion of this discussion. 

The Board has codified the federal NAAQS for nitrogen oxides without substantive 

rev1s1on. All of the deviations fi·om the literal text of the federal NAAQS are itemized in Table 

I. 

Section 243.125: Ozone. USEPA adopted the initial primary and secondary one-hour 

NAAQS for photochemical oxidants21 in 1971. USEP A superseded that primary and secondary 

one-hour standard in 1979 with a standard for ozone. USEP A established a primary and 

secondary eight-hour standard for ozone in 1997 and a more stringent eight-hour standard in 

2008. The evolution of the NAAQS for ozone is summarized as follows: 

1971 Primary and Secondary One-Hour NAAQS for Total Photochemical Oxidants (O.lJ 

(Removed) 

Standard: 0.08 ppm not to be exceeded more than one hour per year 

Citation: 40 C.P.R. 50.9 (1972) (originally 42 C.P.R. 410.9 (1971)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 160 11g/m3 (0.08 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 22384): Recodified without substantive 

reVISIOn 

Febmary 18, 1975 (40 Fed. Reg. 7042): Amended to require the use of federally 

approved monitoring methods (FRMs and FEMs). 

Febmary 8, 1979 (44 Fed. Reg. 8202): Removed 

1979 Primruy and Secondary One-Hour NAAQS for Ozone (OJ) (Revoked as to All 

Areas in Illinois) 

Standard: 0.12 ppm not to be exceeded more than one day per year 

Citation: 40 C.P.R. 50.9(a) (2012) 

21 Photochemical oxidants are pollutants fmmed in the ahnosphere by the reaction of nitrogen 

oxides with hydrocarbons. USEP A, Communications, Education, and Public Affairs, Terms of 

Environment: Glossmy, Abbreviations, and Acronym (Dec. 1997), EPA 175-B-97-001, at 35. 

Ozone is the principal photochemical oxidant. Others are nitr·ogen dioxide, peroxyacetyl 

nitrates, fmmaldehyde, acrolein, and organic peroxides. See Proposed Air Quality Standards, 

R72-7 (July 10, 1975), slip op. at 23-24. 
Feb mary 8, 1979 ( 44 Fed. Reg. 8202): Original adoption as 0.12 ppm (235 

f.tg/m\ 

March 9, 1993 (58 Fed. Reg. 13008): Retained without revision. 

July 18, 1997 (62 Fed. Reg. 38856): Sunset provision added: the standard does 

not apply to an area after USEP A has designated that the area has 

attained the 1979 primary and secondary one hour standard. 

July 20, 2000 (65 Fed. Reg. 45182): Sunset provision revised: the standard does 

not apply to an area once the 1997 primary and secondary eighthour standard is effective and is no longer subject to judicial 

review, and after USEPA has designated that the area has attained 

the 1979 primary and secondary one hour standard. 22 

April30, 2004 (69 Fed. Reg. 23951): Sunset provision revised: the standard does 

not apply to an area one year after USEP A has designated the 

attainment status of the area under the 1997 primary and secondary 

one hour standard. 23 

August 3, 2005 (70 Fed. Reg. 44470): Note added to the one-hour ozone 

attainment designation table in 40 C.F.R. 81.314 stating that the 

1979 one-hour NAAQS for ozone was revoked effective June 15, 

2005. 

1997 Primarv and Secondarv Eight-Hour NAAQS for Ozone (03) (Subject to 

Partial Sunset) 

Standard: 0.08 ppm annual fourth-highest daily maximum, averaged over three 

years 

Citation: 40 C.F.R. 50.1 O(a) (2012) 

July 18, 1997 (62 Fed. Reg. 38856): Original adoption. 

May21, 2012 (77 Fed. Reg. 30160, 30170): Partial sunsetprovisionadded: 24 the 

1997 primary and secondary eight-hour standard will no longer 

22 This modification was a result of the American Trucking Assoc. litigation. See supra note 14. 

By this action, USEPA further amended 40 C.F.R. 81.314 to remove an earlier detetmination 

that the 1997 primary and secondary one-hour NAAQS for ozone does not apply to areas that 

were in compliance with the standard. See 65 Fed. Reg. 45182, 83,220-22 (July 20, 2000); see 

also 63 Fed. Reg. 31014,41-42 (June 5, 1998) (reinstating original detetmination of 

inapplicability); 63 Fed. Reg. 11842,47 (Mar. II, 1998) (withdrawing original determination of 

inapplicability); 63 Fed. Reg. 2726,48-49 (Jan. 16, 1998) (original detetmination of 

inapplicability). 

23 USEP A simultaneously designated the attainment status of all areas of Illinois for the 1997 

eight-hour NAAQS for ozone, effective June 15, 2012. See 69 Fed. Reg. 23858 (Apr. 30, 2004). 

24 The 1997 primary and secondary eight-hour standard continues to apply for all other purposes. 

See 40 C.F.R. 50.!0(c)(2012). USEPA explained that the 2008 eight-hour standard replaced the 

1997 eight-hour standard, but the 1997 standard has been retained for implementation purposes 
apply to an area for transpmtation confmmity purposes only one 

year after USEPA has made a designation of the area for the 2008 

primary and secondary eight-hour standard. 

2008 Primarv and Secondarv Eight-Hour NAAQS for Ozone (0,) (Current) 

Standard: 0.075 ppm annual fourth-highest daily maximum, averaged over three 

years 

Citation: 40 C.F.R. 50.15(a) (2012) 

March 27,2008 (73 Fed. Reg. 16483): Original adoption. 

Three primary and secondary NAAQS for ozone are codified in three federalmles: 40 

C.F.R. 50.9, 50.10, and 50.15. The Board has codified the 2008 primary and secondary eighthour NAAQS for ozone in 35 Ill. Adm. Code 243.125. The Board has replaced the existing 

provision relative to ozone with the text of the federal NAAQS, adding the 1997 primary and 

secondary eight-hour NAAQS to the text. Each of the still-applicable federal provisions relative 

to ozone appears in a separate subsection, with the subsection for each of the standards. 

The Board included the 1979 primary and secondary one-hour NAAQS for ozone in the 

May 16, 2013 proposal for public comment, but removes that standard from the adopted version 

of the mles. For the reasons stated below, the Board has determined that it is not necessary to 

include the 1979 NAAQS. The two NAAQS for ozone are codified as follows: 

Subsection Federal Citation NAAQS 

243.125(a) 40 C.F.R. 50.10 1997 Primary and Secondary Eight-Hour NAAQS for Ozone 

243.125(b) 40 C.F.R. 50.13 2008 Primary and Secondary Eight-Hour NAAQS for Ozone 

The Board does not engage in substantive review of federal standards in the context of an 

identical-in-substance proceeding, except as necessmy to incorporate them into the Illinois air 

regulations. Persons wishing to understand the substance of a federal standm·d should review the 

Federal Register notices by which USEPA has adopted, reviewed, and amended the various 

standards. Those notices are listed in the foregoing review of the federal standards for ozone in 

the initial portion of this discussion. 

The Board has codified the federal NAAQS for ozone without substantive revision. All 

of the deviations from the literal text of the federal NAAQS for Ozone are itemized in Table I. 

Two revisions that the Board has not made warrant discussion. These relate to the sunset of the 

1979 one-hour and the pattial sunset of the 1997 eight-hour NAAQS for ozone. 

Sunset o(the 1979 Prim my and Secondary One-Hour NAAOS (or Ozone. The 

conditions of the sunset clause applicable to the 1979 one-hour standard have been fulfilled. It is 

while USEPA formulates mles for transition from the 1997 standard to the 2008 standard. See 

73 Fed. Reg. 16436, 503 (Mar. 27, 2008). 
possible for the Board to omit the material derived fi·om 40 C.F.R. 50.9 from the adopted version 

of the present amendments. 

The 1979 one-hour NAAQS for ozone has not applied to any area of Illinois after June 5, 

2005. The 1979 standard provides that it no longer applies to an area one year after the effective 

date of its area designation by USEPA for the 1997 primary and secondary eight-hour standard 

for ozone. See 40 C.F.R. 50.9(b) (2012). USEPA designated areas of Illinois for the 1997 

primary and secondary eight-hour NAAQS for ozone effective June 15,2004. See 40 C.F.R. 

81.314 (2012) (the table for the 1979 eight-hourNAAQS for ozone); 69 Fed. Reg. 23858 (Apr. 

30, 2004) (designation of all areas of Illinois). USEPA revoked the 1979 one-hourNAAQS as to 

all areas of Illinois effective June 15, 2005. See 40 CFR 81.314 (table for one-hour NAAQS for 

ozone, note 3; 70 Fed. Reg. 44470, 75 (Aug. 3, 2005) (adding the footnote relating revocation of 

the 1979 NAAQS for ozone to the table of area designations)25 

The Board included the 1979 one-hour NAAQS in the proposal for public comment, but 

now removes that standard from the final version of these rules. The testimony of Mr. Kolaz at 

heming maintained that the Board should remove the revoked 1979 one-hour NAAQS for ozone. 

Tr. at 7-9; Pre-filed testimony of David Kolaz at 3. By PC I, IERG made this point more 

clearly. See PC I at 2-3. The Board cannot adopt standards that do not apply to persons or 

facilities in Illinois. 415 ILCS 5/7.2(a)(l) (2012). 

Partial Sunset ofthe 1997 Prim my and Secondmy Eight-Hour NAAOS (or Ozone. 

The conditions of the sunset clause applicable to the 1997 eight-hour standard will be fulfilled 

before final adoption of the present amendments. This sunset, however, is pattial-for purposes 

of transpmtation confmmity alone. The pmtial sunset occurs one year after the area designations 

for the 2008 eight-hour standard, after June 15,2013. See 40 C.F.R. 50.10(c) (2012); 40 C.F.R. 

81.314 (2012) (the table for the 2008 eight-hour NAAQS for ozone); 77 Fed. Reg. 34221 (June 

II, 2012) (designation of areas surrounding Chicago); 77 Fed. Reg. 30088 (May 21, 2012) 

(designation of the rest of Illinois). The Board has included 40 C.F.R. 50.10 in the present 

amendments due to the pmtial nature of the sunset provision. 

Section 243.126: Lead. USEPA adopted the initial primary NAAQS for lead in 1978. 

See 36 Fed. Reg. 46246 (Oct. 5, 1978). USEP A recently adopted a more-stringent primary 

NAAQS in 2008. The development of the ptimary NAAQS for lead are outlined as follows: 

1978 Primarv Calendar puarterlv Average NAAQS for Lead (Subject to Sunset) 

Standard: 1.5 Jlg/m maximum mithmetic mean averaged over a calendar qumter 

not to be exceeded in total suspended material 

Citation: 40 C.F.R. 50.12(a) (2012) (originally 40 C.F.R. 50.12 (1979)) 

October 5, 1978 (43 Fed. Reg. 46246): Original adoption. 

25 The federal SIP requirements now allow the State to apply to USEPA for removal of the 

obligation for a maintenance plan for the 1979 one-hour standard eight years after such a 

revocation and any time after USEPA has designated all areas of the State for the 1997 eighthom· standard. 40 C.F.R. 51.905(e) (2012). Eight years after that revocation is June 15, 2013. 
November. 12, 2008 (73 Fed. Reg. 66964): Renumbered to subsection (a); sunset 

provision added: the standard does not apply to an area one year 

after USEPA designation of the attainment status of that area under 

the 2008 p1imary and secondary three-month average standard, 

with one exception26• 

2008 Primarv Three-Month Average NAAQS for Lead (Current) 

Standard: 0.15 ~g/m3 arithmetic mean averaged over a three-month period 

Citation: 40 C.F.R. 50.16(a) (2012) 

November. 12, 2008 (73 Fed. Reg. 66964): Original adoption. 

Both primmy NAAQS for lead remain codified in two federal rules: 40 C.P.R. 50.12 and 

50.16. The Board has codified the 2008 primmy three-month NAAQS for lead in 35 Ill. Adm. 

Code 243.126. The Board has replaced the existing provision relative to lead with the text of the 

federal NAAQS, adding the 1978 primmy calendar qumierly NAAQS for lead to the text. Each 

of the federal provisions relative to lead appears in a separate subsection, one for each of the 

1978 and 2008 standards. The two NAAQS for lead are codified as follows: 

Subsection Federal Citation NAAQS 

243.126(a) 40 C.P.R. 50.12 1978 Primary Calendar Qumierly Average NAAQS for Lead 

243.126(b) 40 C.P.R. 50.16 2008 Primary Three-Month Average NAAQS for Lead 

The Board repeats that the Board does not engage in substantive review of federal 

standm·ds in the context of an identical-in-substance proceeding, except as necessmy to 

incmporate them into the illinois air regulations. Persons wishing to understand the substance of 

a federal standard should review the Federal Register notices by which USEPA has adopted, 

reviewed, and amended the various standards. Those notices are listed in the foregoing review 

of the federal standards for lead in the foregoing outline of federal development of the lead 

NAAQS. 

The Board has codified the federal NAAQS for lead without substantive revision. All of 

the deviations from the literal text of the federal NAAQS are itemized in Table 1. The Board 

discusses here only one significant issue relating to the federal standards: sunset provision in the 

1978 primary NAAQS for lead. The issue did not result in deviation from the federal text. 

Sunset o(tlze 1978 Primary Calendar Ouarterlv Average NAAOS for Lead. The 

adoption of the 2008 NAAQS for lead resulted in addition of a sunset clause to the 1978 

NAAQS for lead. The Board does not see that the conditions of the sunset clause have yet been 

met for all areas of Illinois, so the Board has included the 1978 NAAQS in this adopted rule. 

26 The exception relates to areas deemed not in attainment with the 1978 standard before the 

effective date of the 2008 standard. 
When adopting the 2008 standard, USEPA added a sunset clause to the 1978 primary 

calendar quarterly average NAAQS for lead. See 40 C.F.R. 50.!2(b)(2012); 73 Fed. Reg. 66964 

(November. 12, 2008). The sunset clause provides that the 1978 NAAQS no longer applies to an 

area that USEP A has designated for the 2008 standard one year after the effective date of the 

designation, except for areas that USEPA has designated "non-attaimnent" with the 2008 

standard. See 40 C.F.R. 50.12(b) (2012). For non-attaimnent areas, the 1978 standard no longer 

applies after USEP A has approved a plan for attaimnent or maintenance of the 2008 NAAQS. 

See/d. 

For the 2008 NAAQS for lead, US EPA has designated two areas of the state as nonattaimnent and the rest of the State as "unclassifiable/attaimnent." The two non-attaimnent areas 

are segments of Cook and Madison Counties. See 40 C.F.R. 81.314 (2012); 76 Fed. Reg. 72097 

(Nov. 22, 2011); 75 Fed. Reg. 71033 (Nov. 22, 2010). Since the Board cannot find a USEPAapproved plan for attainment or maintenance for those two areas, the 1978 NAAQS for lead 

remains viable in limited areas of the State. The Board has incorporated the 1978 standard for 

lead into the Illinois mles, adding explanation of the status of this NAAQS in an appended Board 

note. 

Non-Inclusion of the 2012 NAAQS for PMz.s and PM10 

The Board monitors USEPA actions in the several identical-in-substance subject areas27 

on an ongoing basis for USEP A actions that would require Board mlemaking activity. If the 

Board observes a USEP A action subsequent to the nominal timefran1e of an identical-insubstance proceeding that affects the same subject matter, the Board has included that later 

action within the mles under development. See, e.g., SDW A Update. USEPA Amendments 

(Janumy 1. 2012 through June 30. 2012. and July 25. 2012), R13-2 (Jan. 24, 2013), slip op. at 3, 

6 (no additional amendments); RCRA Subtitle C Update. USEPA Amendments (July I. 2008 

through December 31. 2008 and June 15. 2010), R09-l6, RCRA Subtitle C Update. USEP A 

Regulations (Janumy I. 2009 through June 30. 2009). Rl0-4 (June 17, 2010), slip op. at 5-6, 272 

(withdrawing amendments); SDWA Update. USEPA Amendments (Janumy I. 2007 though June 

30. 2007 and June 3. 2008), R08-7, SDWA Update. USEPA Amendments (July 1. 2007 though 

December 31. 2007), R08-13 (Dec. 18, 2008), slip op. at 4, 8 (adding amendments). 

On Janum·y 15, 2013, USEPA detennined to retain the 1987 primary and secondmy 24-

hour NAAQS for PM10, revised the data handling conventions applicable to all four of the PM2.s 

NAAQS28, and adopted two new NAAQS for particulate matter29 There are one new NAAQS 

27 Definition of volatile organic mate1ial, NAAQS, underground injection control, wastewater 

pretreatment, RCRA Subtitle C (hazardous waste), underground storage tanks, and RCRA 

SubtitleD (municipal solid waste landfill) regulations. See 415 ILCS 5/9.l(e), lO(H), 13(c), 

13.3, 22.4(a) and (c), and 22.40(a) (2012) (respectively). 

28 The 1997 and 2006 Primary and secondary aruma! average and 24-hour NAAQS for PM25• 
for PM10 and three new NAAQS for PM25. Those standards are the following (using the fonnat 

employed above for all of the historical and existing NAAQS): 

1987 Primarv and Secondarv 24-Hour NAAQS for PM10 

Standard: !50 )lglm3 not to be exceeded more than once per year, on a three-year 

average basis 

Citation: 40 C.P.R. 50.6(a) (2012) 

July I, 1987 (52 Fed. Reg. 24634): Original adoption. 

July 18, 1997 (62 Fed. Reg. 38652): Sunset provision added. 30 

December 22, 2000 (65 Fed. Reg. 80776): Sunset provision removed31 

January 15,2012 (78 Fed. Reg. 3086): Retained without revision. 

1997 Primarv and Secondarv Annual Average NAAQS for PM, 5 

Standard: 15.0 )lg/m3 arithmetic mean, averaged over three years 

Citation: 40 C.P.R. 50.7(a) (2012) (originally 40 C.P.R. 50.7(a)(l) (1998)) 

July 18, 1997 (62 Fed. Reg. 38652): Original adoption. 

July 30, 2004 (69 Fed. Reg. 45592): Renumbered to subsection (a). 

Januaty 15,2012 (78 Fed. Reg. 3086): Retained without revision, but subject to 

revised data handling conventions in appendix N to 40 C.P.R. 50. 

1997 Primarv and Secondarv 24-Hour NAAQS for PM,.5 

Standard: 65 )lglm3 98th percentile, averaged over three years 

Citation: 40 C.P.R. 50.7(a) (2012) (originally 40 C.P.R. 50.7(a)(l) (1998)) 

July 18, 1997 (62 Fed. Reg. 38652): Original adoption. 

July 30, 2004 (69 Fed. Reg. 45592): Renumbered to subsection (a). 

Janumy 15, 2012 (78 Fed. Reg. 3086): Retained without revision, but subject to 

revised data handling conventions in appendix N to 40 C.P.R. 50. 

29 The USEPA NAAQS webpage (www.epa.gov/ttn/naaqs/standards/prnls_pm_histmy.html) 

lists all of the remaining standards as 2012 standards: the ptimary annual NAAQS for PM2.5, 

added as 40 C.P.R. 50.18(a); the secondary annual NAAQS for PM2.5, which remains unchanged 

as 40 C.P.R. 50.13(a) (the 2006 standard); the primmy and secondary 24-hour NAAQS for 

PM2.s, which was added as 40 C.P.R. 50.18(a) and remains codified as 40 C.P.R. 50.13(a) (the 

2006 standard); and the primary and secondary 24-hour NAAQS for PM10, which remains 

codified as 40 C.P.R. 50.6(a) (the 1987 standard). 

30 Not described in this summary outline because USEP A subsequently removed the sunset 

provision. See 40 C.P.R. 50.6(d) (1998) (the removed sunset provision). 

31 As a result of the decision in American Trucking Assoc. v. EPA, 175 F. 2d 1027, modified en 

bane, 195 F.3d 4 (D.C. Cir. 1999), aff'd in part and rev 'din part sub nom. Whitman v. American 

Trucking Assoc., 531 U.S. 457, 121 S. Ct. 903, 149 L. Ed. 2d 69 (2001), on remand, 283 F.3d 

355 (D.C. Cir. 2002). 
2006 Primary and Secondarv Annual Average NAAOS for PM, 5 

Standard: 15.0 [.lg/m3 arithmetic mean, averaged over three years 

Citation: 40 C.F.R. 50.13(a) (2012) 

October 17, 2006 (71 Fed. Reg. 61144): Original adoption. 

January 15, 2012 (78 Fed. Reg. 3086): Retained without revision, but subject to 

revised data handling conventions in appendix N to 40 C.F.R. 50. 

2006 Primarv and Secondarv 24-Hour NAAQS for PM,_5 

Standard: 35 [.lg/m3 98th percentile, averaged over three years 

Citation: 40 C.F.R. 50.13(a) (2012) 

October 17, 2006 (71 Fed. Reg. 61144): 01iginal adoption. 

January 15, 2012 (78 Fed. Reg. 3086): Retained without revision, but subject to 

revised data handling conventions in appendix N to 40 C.F.R. 50. 

2012 Primarv Annual Average NAAQS for PMo,.:; 

Standard: 12.0 [.lg/m3 arithmetic mean, averaged over three years 

Citation: 40 C.F.R. 50.18(a), as added at 78 Fed. Reg. 3086,277 (Jan. 15, 2013) 

January 15,2012 (78 Fed. Reg. 3086): Original adoption. 

2012 Primarv 24-Hour NAAQS for PM2.5 

Standard: 35.0 [.lg/m3 98th percentile, averaged over three years 

Citation: 40 C.F.R. 50.18(a), as added at 78 Fed. Reg. 3086, 277 (Jan. 15, 2013) 

Janumy 15, 2012 (78 Fed. Reg. 3086): Original adoption. 

The Board has opted not to include the January 15,2013 federal amendments relating to 

PM25 with this initial adoption of identical-in-substance NAAQS standards. Adding the 

amendments to the present proceeding would cause minor delay in adoption of the present initial 

amendments. The Board sees no benefit in adding the new 2012 NAAQS to this proceeding. 

The State and USEP A will begin monitoring for the new standards as a matter of federal law 

whether the Board adopts the Janua1y 13, 2013 federal amendments in this proceeding or in a 

separate proceeding that could conclude as late as January 14,2014.32 

Responses to Requests for Public Comments 

The Board requested comments on general aspects of the May 16, 2013 proposal for 

public comment, such as the Board's approach to the statutory mandate, the standardized naming 

of the NAAQS in the text, the choice of structure, complete replacing of the existing Illinois 

standards, the incorporations by reference, etc. The Board further requested public comments on 

specific aspects of the proposal. The specific requests for comments are itemized as follows: 

32 See 415 ILCS 5/7.2(b) (2012). 
I. Removal of monitoring locations requirement Is it tme that the design, location, 

and operation of monitoring locations and networks occurs as a matter of federal 

law? Is it tme that the design, location, and operation of monitoring locations and 

networks are subject to USEP A review and approval? Is there any reason the 

Illinois NAAQS regulations should include incorporation of 40 C.P.R. 58 by 

reference? If the Board should retain the monitoring requirement, is the following 

language in 35 Ill. Adm. Code 243.106 sufficient? 

All monitoring pe1formed to fulfill the requirements ofthis Pm1must be 

perfom1ed at stations a11d networks of stations designed, located, a11d 

operated according to plans approved by USEP A according to the 

requirements of 40 C.P.R. 58. 

IERG stated supp011 for removal of the monitoring locations requirement, 

observing that the requirement is not a proper component of ambient air quality 

standards. Pre-filed testin1ony of David Kolaz at 2. 

2. Removal of non-degradation requirement Do the federal PSD requirements 

render the non-degradation mle of 35 Ill. Adm. Code 243.104 unnecessa1y? Is 

there any way that the Board should perceive non-degradation as a segment of the 

federal NAAQS? 

IERG stated support for removal of the non-degradation requirement, observing 

that the requirement is not a proper component of ambient air quality standards. 

Pre-filed testin1ony of David Kolaz at 2. 

3. USEPA approvals ofPRMs and PEMs: Will the unavoidable delay in 

incorporation of USEP A methods designations into the illinois regulations create 

difficulty in implementation of the federal NAAQS in Illinois? Is there any 

available altemative that could minimize the delay? 

The Board received no comments in this regard. 

4. Expiration of the 1979 one-hour NAAQS for ozone: Is it tme that the 1979 

standard for ozone will not apply to any area of Illinois after July 20, 2013? If so, 

may the Board remove the 1979 one-hour sta11dard for ozone after that date? 

IERG stated support for removal of the 1979 one-hour NAAQS for ozone. Mr. 

David Kolaz observed on behalf of IERG that this NAAQS was revoked in 2005 

as to all areas in Illinois. Tr. at 7-10; Pre-filed testimony of David Kolaz at 2. 

IERG made this point also in PC I. 

5. Expiration of the requirement for a maintenance plan for the 1979 one-hour 

NAAOS for ozone: Is it tme that the State may apply to USEP A to remove the 

requirement for a maintenance plan for the 1979 one-hour NAAQS for ozone 
after June 15, 2013? If so, may the Board remove the 1979 one-hour standard for 

ozone after that USEP A approval? 

The Board received no comments in this regard. 

6. Partial expiration of the 1997 PJimary and secondmy eight-hour NAAQS for 

ozone: Is it hue that that the 1997 eight-hour standard for ozone will no longer 

apply to any area after June 15, 2013 for transportation confonnity purposes? For 

what purposes will that 1997 standard continue to apply? What event or series of 

events could occur within the next few years that could wan·ant removal of the 

1997 from the Illinois regulations? 

The Board received no comments in this regard. 

7. Expiration of the 1978 primmy calendar qum1erly average NAAQS for lead: Is it 

true that the 20 II and 2012 area designations for the 2008 NAAQS for lead 

rendered the 1978 calendar qum1erly NAAQS for lead inapplicable to all areas of 

Illinois except for the two limited non-attainment areas? What is the cun·ent 

status of the State obtaining an approved attainment or maintenance plan for those 

two areas? When USEP A has approved an attainment or maintenance plan for 

those areas, should the Board remove the 1978 NAAQS for lead fi·om the Illinois 

regulations? 

The Board received no comments directly in this regard. Rather, Mr. David 

Kolaz testified that, as a general matter, the Board should remove revoked and 

inapplicable federal standards from the Illinois regulations. Tr. at 9; Pre-filed 

testimony of David Kolaz at 2-3. 

8. General re removal of expired NAAOS: When the Board observes that the 

conditions in a sunset clause applicable to a NAAQS may have been fulfilled, 

should the Board propose deletion of that standard? As a second altemative, 

should the Board wait until USEP A has expressly codified that the NAAQS does 

not apply to any area in Illinois? As a second altemative, should the Board leave 

that NAAQS in the Illinois rules until USEP A has removed that standard fi·om 40 

C.F.R. 50? 

Mr. David Kolaz testified that the Board should remove revoked and inapplicable 

federal standards from the Illinois regulations. Tr. at 9; Pre-filed testimony of 

David Kolaz at 2-3. 

Deviations from the Literal Text of the Federal Amendments 

and Non-Federallv Derived Corrections and Clarifications 

The Board routinely examines federal amendments and the base text of rules open for 

amendments to find any areas that need conection or clarification. JCAR and the Office of the 

Secretary of State also routinely examine the text and suggest cmTections and clarifications. 
Sometimes suggestions arise from the Agency, US EPA, or members of the regulated 

community. The Board often makes revisions as a result. The revisions thus made are not 

directly de1ived from federal amendments. The Board is ever mindful of the limited discretion 

authorized in the context of an identical-in-substance proceeding. The Board is limited to "those 

changes that are necessary for compliance with the Illinois Administrative Code," "technical 

changes that in no way change the scope or meaning of any portion of the regulations," and 

"apparent typographical and grammatical errors." See 415 ILCS 5/7.2(a) and (a)(7) (2012). 

Thus, the Board will only make minor, non-substantive corrections and clarifications in this 

context. These CO!Tections are non-substantive in effect. Tables follow that document the 

corrections and clmifications made in this proceeding. The first lists the deviation from the 

literal text of the USEPA amendments involved in this proceeding. The second lists the 

CO!Tection made in this docket that was not prompted by federal mnendments. 

Tabulations of Deviations from the Literal Text of the Federal Amendments and 

Miscellaneons Board Housekeeping Amendments. 

The tables below list numerous CO!Tections and amendments that are not based on current 

federal mnendments. Table 1 (beginning immediately below) lists a number of federal 

amendments that the Board has not included in this docket. Table 1 gives a brief explanation 

why the Board has declined to make each. Table 1 (beginning immediately below) includes 

deviations made in the adopted text from the verbatim text of the federal amendments. Table 2 

(beginning inunediately after Table 1 on page 91) contains corrections and clarifications that the 

Board made in the base text involved in the present amendments. The amendments listed in 

Table 2 are not directly derived from the cun·ent federal amendments. Some of the entries in 

these tables are discussed further in appropriate segments of the general discussion beginning at 

page 6 of this opinion. Table 3 (beginning on page ### below) is a listing of revisions made to 

the text ofthe amendments from that proposed and set forth in the Board's opinion and order of 

May 16,2013. Table 3 indicates the changes made, as well as the source that suggested each of 

the changes. Table 4 (on page### below) indicates suggested revisions that the Board has not 

made in adopting these amendments. Each entry gives a brief explanation why the Board did not 

incorporate the suggested change. 

Table 1: 

Deviations from the Text of the Federal Rules 

Illinois Section 40 C.P.R. Section Revision(s) 

243 table of contents, 50.14 heading Removed "Treatment of' from before 

243.105 heading "air quality monitoring data"; capitalized 

the first letter of each word in the 

heading. 
243 table of contents, Table 1 to 50.14(c)(2)(vi) Removed "Data to be Used for 

24 3 .I 05 heading heading Designations Decisions" from before 

"for New or Revised NAAQS"; changed 

the format from large and small capital 

letters to standard format with 

capitalization of the first letter of each 

word in the heading. 

243.101 generally 40 C.F.R. 50.1 Replaced the existing language with new 

language more directly derived from the 

corresponding federal provision. 

243.101 preamble 40 C.F.R. 50.1(a) Added the affirmative sentence, "For the 

purposed of this Part, terms listed below 

... this Section."; changed "herein" to 

"in this Section"; changed "shall" to 

"will"; changed "Act" to "the Act; the 

CAA, incorporated by reference in 

Section 243.108; or 35 Ill. Adm. Code 

201.102" (which are Illinois law that 

should be consistent with the CAA). 

243.101 "Act" 40 C.F.R. 50.l(b) Placed the defined term in quotation 

marks; changed the definition fi"om 

meaning the federal CAA, as amended, 

to mean the Enviromnental Protection 

Act. 

243.101 "Agency" 40 C.F.R. 50.l(c) Placed the defined term in quotation 

marks; changed the defmition from 

meaning USEP A, as amended, to mean 

the lllinois EPA. 

243.101 "Clean Air 40 C.F.R. 50.l(b) Created the separate defined term to 

Act" mean the federal statute; placed the 

defined te1m in quotation marks; added 

the altemative defined abbreviated te1m 

"CAA" in quotation marks; added 

"federal" for clarity; changed "42 U.S.C. 

1857-18571, as amended by Pub. L. 91-

604" to "42 U.S.C. 7401 et seq., as 

amended." 
243.101 "exceedance 40 C.F.R. 50.1(1) Placed the defined te1m in quotation 

ofanNAAQS" marks; moved the defmition into 

alphabetic order; changed the long 

defined te1m "exceedance with respect 

to a national ambient air quality 

standard" to the shorter form 

"exceedance of a NAAQS"; changed 

"such standard" to "such NAAQS." 

243.101 "exceptional 40 C.F.R. 50.l(j) Placed the defined tenn in quotation 

event" marks; moved the definition into 

alphabetic order; added "fulfills all of 

the following criteria" and a colon after 

"that"; divided so to place each criterion 

into a separate subsidiary paragraph; 

added "the event" (four times); changed 

the commas to semicolons to separate 

each criterion; changed "the event is an 

event caused" to "the event is caused"; 

changed "Administrator" to "USEPA"; 

changed "it does not" to "an 

'exceptional event' does not"; added 

"any of the following," followed by a 

colon, and subdivided the conditions 

into subsidimy paragraphs; changed the 

separating commas to semicolons. 
24 3.101 "federal 40 C.P.R. 50.l(g), Placed the defined tern1 in quotation 

equivalent method" 50.11(d)(2), and 53.1 marks; moved the definition into 

alphabetic order; added "federal" to the 

defined tenn and the abbreviated 

alternative definition "PEM" based on 

the defmition that appears at closely 

related 40 C.P.R. 53.1; changed "that 

has been designated" to active-voice 

"that USEP A has designated"; changed 

"in accordance with patt 53 of this 

chapter" to "pursuant to 40 CPR 53 and 

which is listed included in the List of 

Designated Methods, including later 

updates, as incorporated by reference ... 

243.108"; changed "it does not include" 

to "the tenn 'federal equivalent method' 

does not include"; changed "for which 

an equivalent method designation has 

been cancelled" to active-voice "for 

which USEP A has cancelled or 

superseded an equivalent method 

designation"; changed"§ 53.11 or 

§ 53.16 of this chapter" to "40 CPR 

53.11 or 53.16"; added the parenthetical 

"as reflected by ... Section 243.108." 

243.101 "federal 40 C.P.R. 50.1 (g), Added explanation of the derivation of 

equivalent method" 50.11 ( d)(2), and 53.1 the defmition from multiple sources; 

Board note added explanation of "including later 

updates"; added explanation of the 

effectiveness of designation of an PEM 

and cancellation of an PEM. 
243.101 "federal 40 C.P.R. 50.l(f) and Placed the defmed te1m in quotation 

reference method" 53.1 marks; moved the defmition into 

alphabetic order; added "federal" to the 

defined te1m and the abbreviated 

alternative definition "PRM" based on 

the definition that appears at closely 

related 40 C.P.R. 53.1; changed "that 

has been designated" to active-voice 

"that USEPA has designated" (twice); 

changed "in an appendix to this part" to 

"in an appendix to 40 CPR 50, 

incorporated ... 243.108"; changed "in 

accordance with pmt 53 of this chapter" 

to "pursuant to 40 CPR 53 and which is 

listed included in the List of Designated 

Methods, including later updates, as 

incorporated by reference ... 243.1 08"; 

changed "it does not include" to "the 

term 'federal reference method' does not 

include"; changed "for which an 

reference method designation has been 

cancelled" to active-voice "for which 

USEP A has cancelled or superseded a 

reference method designation"; changed 

"§ 53.11 or§ 53.16 of this chapter" to 

"40 CPR 53.11 or 53.16"; added the 

parenthetical "as reflected in ... Section 

243.108." 

243.101 "federal 40 C.P.R. 50.l(f) and Added explanation of the derivation of 

reference method" 53.1 the definition from multiple sources; 

Board note added explanation of"including later 

updates"; added explanation of the 

effectiveness of designation of an PRM 

and cancellation of an PRM. 

243.101 "micrograms 40 C.P.R. 50.6(a); Added the defmition of the te1m and the 

per cubic meter" 50.7(a), and 50.13(a) and abbreviated form to support consistent 

58.1 (definitions of use of the abbreviated form throughout 

PM2.s, PM10, PM10c, and the text. 

PM10.2.sl 
243.101 "micrograms 40 C.F.R. 50.6(a); Added explanation that the Board added 

per cubic meter" 50.7(a), 50.8(a)(l) and the defmitions of "micrograms per cubic 

Board note (a)(2), and 50.13(a) and meter" and "milligrams per cubic 

58.1 (definitions of meter." 

PM2.s, PM10, PM10c, and 

PM10-2s) 

243.101 "milligrams 40 C.F.R. 50.8(a)(l) and Added the definition of the te1m and the 

per cubic meter" (a)(2) abbreviated fonn to support consistent 

use of the abbreviated form throughout 

the text. 

243.101 "National 40 C.F.R. 50 generally, Bon·owed the definition of the te1m and 

Ambient Air Quality and "Terms of the abbreviated fonn to support 

Standards" Environment: Glossmy, consistent use of the abbreviated form 

Abbreviations, and tln·oughout the text; changed plural 

Acronyms" (Dec. 1997) "National Ambient Air Quality 

Standards" to singular; changed plural 

"standards" to singular "a standard"; 

changed "EPA" to "USEP A"; changed 

"the country" to "the United States." 

243.101 "National 40 C.F.R. 50 generally, Added explanation of the added 

Ambient Air Quality and "Terms of definition and its source. 

Standards" Board note Environment: G1ossmy, 

Abbreviations, and 

Acronyms" (Dec. 1997) 

243.101 "natural 40 C.F.R. 50.1(±) and Placed the defined term in quotation 

event" 53.1 marks; moved the definition into 

alphabetic order. 

243.101 "parts per 40 C.F.R. 50 generally, Derived the defmition and the 

billion" and "Te1ms of abbreviated fmm to support consistent 

Environment: Glossary, use of the abbreviated form throughout 

Abbreviations, and the text. 

Acronyms" (Dec. 1997) 

243.101 "parts per 40 C.F.R. 50 generally, Added explanation of the added 

billion" Board note and "Te1ms of definition and the definition of "parts per 

Environment: Glossmy, million" and their source. 

Abbreviations, and 

Acronyms" (Dec. 1997) 
243.101 "pmts per 40 C.F.R. 50 generally, Derived the definition and the 

million" and 'Te1ms of abbreviated fmm to support consistent 

Environment: Glossary, use of the abbreviated fmm throughout 

Abbreviations, and the text. 

Acronyms" (Dec. 1997) 

243.101 "PM,o" 40 C.F.R. 50.6(c) Derived the defmition of the abbreviated 

parenthetical fmm to suppmt consistent use of the 

abbreviated fonn throughout the text; 

placed the defined te1m in quotation 

marks; changed "pmticles having" to 

"pmticulate matter that has"; added the 

abbreviation ")lm" in parentheses. 

243.10 I "PM25"Board 40 C.F.R. 50.6(c) Added explanation of the added 

note parenthetical definition and the definition. 

243.101 "PM2.s" 40 C.F.R. 50.7(a) Derived the definition of the abbreviated 

parenthetical fonn to support consistent use of the 

abbreviated form tlu·oughout the text; 

placed the defined tem1 in quotation 

marks; changed "pa1ticles having" to 

"pmticulate matter that has"; added the 

abbreviation ")lm" in parentheses. 

243.101 "PM10"Board 40 C.F.R. 50.7(a) Added explanation of the added 

note parenthetical definition and the definition. 

243.101 "traceable" 40 C.F.R. 50.l(h) Placed the defined term in quotation 

marks; moved the defmition into 

alphabetic order; added the comma 

before "such as a National Bureau of 

Standards ... reference Mmmal (CRM)" 

to offset the parenthetical. 

243.101 "USEPA" 40 C.F.R. 50. I( c) Added the definition based on the 

federal definition of"Agency"; changed 

the defmed tem1 to "USEPA"; added 

"United States" before "Environmental 

Protection Agency." 

243.101 "USEPA" 40 C.F.R. 50.!(c) Added explanation of the derivation and 

Board note use of the defined term in the text. 

243.101 Board note 40 C.F.R. 50.1 generally Added explanation of the derivation of 

this Section. 
243.102 heading 50.2 heading Changed the heading from "Preamble" 

to "Scope" to conespond with the 

federal regulations. 

243.102 generally 50.2 generally Replaced the existing language of this 

Section with that of the conesponding 

federal regulation. 

243.102(a) 50.2(a) Changed "as set fm1h in this pm1" to 

"This Pm1 sets fm1h" and moved it to the 

beginning of the provision; changed 

"national primary and secondary 

ambient air quality standards" to use the 

defined abbreviation "the NAAQS"; 

added "adopted by USEP A"; changed 

"section 1 09 of the Act" to "section I 09 

of the CAA (42 USC 7409)"; added 

"and incorporated into this Part pursuant 

to 415 ILCS 5/7.2 and 10(H)." 

243.102(b) 50.2(b) Added the parenthetical "(primary 

NAAQS)"; changed "which the 

Administrator judges" to "that USEP A 

has judged" (twice); added the 

parenthetical "(secondary NAAQS)"; 

changed "such standards" to "these 

standards"; changed "primary and 

secondary standards" to "primm·y and 

secondary NAAQS"; changed "the 

Administrator" to "USEP A" 

243.102(c) 50.2(c) Changed "primary and secondary 

ambient air quality standards" to 

"primary and secondary NAAQS"; 

changed "any State or Indian country" to 

"this State." 

243.102 Board note 40 C.P.R. 50.2 generally Added explanation of the derivation of 

this Section. 

243.103 None Retained the applicability statement, 

despite the lack of a federal counterpm1. 
243.105 generally 50.14 generally Added the provision relative to 

monitoring data and exceptional events 

that had not counterpatt in the Illinois 

regulations. 

243.105 heading 50.14 heading Removed "Treatment of'' from before 

"air quality monitoring data"; capitalized 

the first letter of each word in the 

heading. 

243.105(a)(l) 50.14(a)(l) Changed "a State" to "the Agency"; 

change "EPA" to "USEP A"; moved 

"from use in the detenninations" from 

before "by demonstrating" to follow 

"exclude"; changed plural "exceedances 

or violations ... that are" to "an 

exceedance ... that is"; changed 

"national ambient air quality standard" 

to the defined abbreviation "NAAQS"; 

divided the run-on sentence after 

"exceptional event" by addition of a 

period and "the Agency must"; changed 

"by demonstrating to USEP A's 

satisfaction" to active-voice 

"demonstrate to USEPA"; changed 

"such event" to "the event." 

243.105(a)(2) 50.14(a)(2) Added the indefinite atticle before 

"demonstration"; changed "exceedance 

or violation" to "exceedance"; changed 

"such standard" to "an NAAQS." 

243.105(b) 50.14(b) Changed "EPA" to "USEP A"; added 

"USEP A has stated ... as follow" and 

an ending colon. 
243.105(b)(l) 50.14(b)(l) Added the topical heading "Exceptional 

events."; changed "EPA" to "USEPA"; 

added "has stated that it will"; changed 

"exceedances or NAAQS violations" to 

the singular defined term "exceedance of 

an NAAQS"; changed "a State 

demonstrates to EPA's satisfaction" to 

"the Agency has demonstrated"; 

changed "one or more national ambient 

air quality standards" to "one or more 

NAAQS"; created an independent clause 

by placing a comma before and 

changing "and otherwise satisfies" to 

"and the Agency otherwise satisfies"; 

changed "this section" to "40 CFR 

50.14." 

243.105(b)(2) 50.14(b)(2) Added the topical heading "Fireworks 

displays."; changed "EPA" to 

"USEPA"; added "has stated that it 

will"; changed "exceedances or NAAQS 

violations" to the singular defined te1m 

"exceedance of an NAAQS"; changed 

"a State demonstrates to EPA's 

satisfaction" to "the Agency has 

demonstrated"; changed "one or more 

national ambient air quality standards" 

to "one or more NAAQS"; changed "and 

otherwise satisfies" to "and the State 

othetwise satisfies" preceded by a 

comma for an independent clause; 

changed "such data" to "USEP A has 

stated that these data"; changed "a State 

demonstrates" to "the Agency has 

demonstrated"; changed "such use of 

fireworks" to "the use of fireworks"; 

added a comma before and after 

"including ... celebrations" to offset the 

parenthetical and add clarity; changed 

"this section" to "40 CFR 50.14." 
243.105(b)(3) 50.14(b)(3) Added the topical heading "Prescribed 

fires."; changed "EPA" to "USEP A" 

(three times); added "has stated that it 

will"; changed "exceedances or NAAQS 

violations" to the singular defined term 

"exceedance of an NAAQS"; changed 

"a State demonstrates to EPA's 

satisfaction" to "the Agency has 

demonstrated"; changed "one or more 

national ambient air quality standards" 

to "one or more NAAQS"; created an 

independent clause by placing a comma 

before and changing "and otherwise 

satisfies" to "and the Agency othe1wise 

satisfies"; changed "this section" to "40 

CFR 50.14"; changed "defmition in 

§ 50.1 (j)" to "defmition of"exceptional 

event in Section243.101"; changed 

"State" to "Agency"; changed "if' to 

"the State"; added the parenthetical 

abbreviation "(SMP)"; changed "State" 

to lower-case "state"; changed "the 

State" to "the Agency"; changed "its" to 

"the State's"; changed "a SMP" to "an 

SMP." 

243.105(b) Board note 50.14(b) Added explanation of the shift fi·om 

"EPA shall" to "USEP A has stated that 

' it will" in all occunences in this 

subsection; added explanation of 

reliance on the defined term 

"exceedance of an NAAQS" in place of 

the federal language. 

243.105(c)(l) 50.14(c)(l) Moved the text of 40 CFR 50.14 

(c)(l)(i) into subsection (c)(1),since 

there is no paragraph (c)(l)(ii); changed 

"All States and, where applicable, their 

political subdivisions" to "the Agency 

or, where the Agency has delegated 

authority pursuant to Section 4(g) or (r) 

of the Act [415 ILCS 5/4(g) or (r), the 

Agency's delegatee"; changed 

"exceedances of an applicable air quality 

standard" to the defined te1m to 

"exceedances of an NAAQS." 
243.1 05( c)(2)(A) 50.14( c)(2)(i) Changed "a State shall" to "the Agency 

must"; changed "EPA" to "USEP A"; 

changed "exceedance of an applicable 

air quality standard" to the defined te1m 

"exceedance of an NAAQS"; changed 

"AQS" to "federal air quality system 

(AQS)." 

243.1 05( c)(2)(B) 50.14(c)(2)(ii) Changed "shall" to "must" (twice); 

changed "exceedance of an applicable 

air quality standard" to the defined te1m 

"exceedance of an NAAQS"; changed 

"EPA notifies the State" to "USEP A 

notifies the Agency" and moved it from 

before "by placing as concunence flag" 

to follow "until"; changed "of its 

concunence following the State's" to 

"of USEP A concunence following the 

Agency's"; changed ''its demonstration" 

to "a den1onstration." 

243.1 05( c)(2)(C) 50.14( c )(2)(iii) Added commas before and after the 

parenthetical "together with ... the 

event"; changed "shall" to "must"; 

changed "EPA" to "US EPA"; changed 

"July 1st" to "July 1." 

243.1 05( c)(2)(D) 50.14( c)(2)(iv) Replaced the federal language with 

explanation of omission of that 

language. 

243.1 05( c)(2)(E) 50.14(c)(2)(v) Replaced the federal language with 

explanation of omission of that 

language. 
243.1 05( c)(2)(F) 50.14( c)(2)(vi) Changed "when EPA" to "USEP A has 

stated that when USEP A"; changed "its" 

to "USEP A"; added the comma before 

"and providing" to offset the final 

element of a series; changed "Table 1 

provides the schedule" to "Table A 

provides the existing schedule"; changed 

"shall apply" to "apply"; changed 

"which" to "that" for a restrictive 

relative clause; changed "EPA 

anticipates revising Table 1" to "US EPA 

has stated that it will revise the table 

upon which Table A is based." 

243.1 05( c)(3)(A) 50.14(c)(3)(i) Changed "a State that has flagged ... 

and is requesting exclusion of ... data" 

to "when the Agency has flagged ... 

and is requesting exclusion of ... data 

shall, the Agency must"; changed "to 

EPA" to "to USEP A" and moved it from 

after "data exclusion" to follow "a 

demonstration"; changed "the lesser of, 

3 years following ... was recorded or, 

12 months" to "the sooner of three years 

following ... or 12 months"; changed "a 

State" to "the Agency"; changed EPA" 

to "USEP A"; moved "to USEPA" from 

after "demonstration" to follow "must 

submit"; added a comma before "along 

with its demonstration" for a 

parenthetical clause. 

243.1 05( c)(3)(B) 50.14(c)(3)(ii) Replaced the federal language with 

explanation of omission of that 

language. 

243.1 05(c)(3)(C) 50.14( c )(3 )(iii) Replaced the federal language with 

explanation of omission of that 

language. 

243.1 05( c)(3)(D) 50.14( c)(3)(iv) Changed "shall" to "must"; changed 

evidence that" to "the following 

evidence." 

243.1 05( c)(3)(D)(i) 50.14( c)(3)(iv)(A) Added "that"; changed "criteria" to 

"definition of "exceptional event." 
243.1 05( c)(3)(D)(ii) 50.14( c)(3 )(iv)(B) Added "that." 

243.1 05( c)(3)(D)(iii) 50.14( c)(3)(iv)(C) Added "that." 

243.1 05( c)(3)(D)(iv) 50.14( c)(3)(iv)(D) Added "that." 

243.1 05( c)(3)(E) 50.14(c)(3)(v) Changed "State" to "Agency." 

243.105 Board note 40 C.F.R. 50.14 generally Added explanation of the derivation of 

this Section. 

243.107 50.3 Added commas before and after "for 

purposes of ... lead" to offset it as a 

parenthetical; added commas before and 

after "for purposes of ... Section 

243.126(b)" to offset it as a 

parenthetical; changed "shall" to "must". 

See the entry for this provision in Table 

2 below. 

243.107 Board note 50.3 generally Added explanation of the de1ivation of 

this Section. 

243.108 50.4(c); 50.5(b); 50.6(a), Added this provision for inclusion of 

(c)(1), and (c)(2); required methods and interpretations by 

50.7(b)(l) and (b)(2); incmporation by reference to the 

50.8(b)(l) and (b)(2); appendices to 40 C.F.R. 50 and the List 

50.9(a); 50.IO(a) and (b); of Designated Methods. 

50.1l(d)(l), (d)(2), (e), 

and (f); 50.12(a); 

50.13(a)(l), (a)(2), (b), 

and (c); 50.15(a) and (b); 

50.16(a)(l), (a)(2), and 

(b); 50.17(b) and (c); and 

Appendices A-1, A-2, B, 

C, D, F, G, H, I, J, K, L, 

M, N, 0, P, Q,R, S, S, 

and T to 40 C.F.R. 50 

generally 

243.120 50.6, 50.7, and 50.13 Replaced the existing language of this 

generally Section with that of the coJTesponding 

federal regulations. 
243.120(a) 50.6 heading Changed "national prima1y and 

secondary ambient air quality standards 

for PM10" to "1987 primary and 

secondary 24-hour NAAQS for PM10." 

243.120(a)(l) 50.6(a) Changed "national primary and 

secondary 24-hour ambient air quality 

standards for pm1iculate matter" to 

"1987 prima1y and secondary 24-hour 

NAAQS for PM10"; changed 

"micrograms per cubic meter ([Lg/m

3

)" 

to the defined te1m "[Lg/m

3

"; changed 

"standards are" to "1987 primary and 

secondary 24-houor NAAQS for PM10 

is"; changed "this pm1" to "40 CFR 50, 

incorporated by reference ... Section 

243.108." 

243.120(a)(2) 50.6(b) Replaced the federal designation 

"reserved" with a statement that 

maintains structural parity with the 

coJTesponding federal rule. 

243.120(a)(3) 50.6(c) Changed "primary and secondary 

standards" to "1987 primary and 

seconda1y 24-hour NAAQS for PM10"; 

changed Hshall" to Hmust"; removed the 

parenthetical "(particles with an 

aerodynamic dimneter less than or equal 

to a nominallO micrometers)," which 

has become the basis for a definition of 

"PM10" in Section 243.101 (see the entry 

above in this Table 1 ); added "by a 

method that fulfills either of the 

following requirements." 
243.120(a)(3)(A) 50.6(c)(l) Changed "a reference method" to the 

defined abbreviation "an FRM''; 

changed "this part" to "40 CFR 50, 

incorporated by reference ... Section 

243.108"; added "by USEPA and listed 

in" after "and designated"; changed "in 

accordance with part 53 of this chapter" 

to "in the List of Designated Methods, 

incorporated by reference in Section 

243.1 08"; changed the ending comma to 

a semicolon. 

243.120(a)(3)(B) 50.6(c)(2) Changed "an equivalent method" to the 

defined abbreviation "an FEM"; added 

"by USEP A and listed in" after "and 

designated"; changed "in accordance 

with patt 53 of this chapter" to "in the 

List of Designated Methods, 

incorporated by reference in Section 

243.108." 

243.120(a) Board note 50.6 generally Added explanation of the derivation of 

subsection (a); added explanation of 

USEP A removal of a transitional 

provision relative to the 1987 and 1997 

NAAQS for PM as a result of litigation. 

243.120(b) 50.7 heading Changed "national primary and 

secondary ambient air quality standards 

for PM2.5" to "1997 primary and 

secondary annual average and 24-hour 

NAAQS for PM2.5." 
243.120(b)(l) 50.7(a) Changed "the national primary and 

secondary 24-hour ambient air quality 

standards for pmticulate matter are ... 

annual arithmetic mean concentration, 

and ... 24-hour average concentration" 

to "1997 p1imary and secondary annual 

average NAAQS for PM10 is ... , annual 

arithmetic mean concentration, and ... , 

24-hour average concentration,"; 

changed "micrograms per cubic meter 

(J.tg/m3

)" to the defined term "J.tg/m3

"; 

removed the parenthetical "(particles 

with an aerodynamic diameter less than 

or equal to a nominal2.5 micrometers)," 

which has become the basis for a 

definition of "PM2.s" in Section 24 3.101 

(see the entry above in this Table 1); 

changed "either" to "by a method that 

fulfills the either of following 

requirements.'' 

243.120(b )(1 )(A) 50.7(a)(l) Changed "a reference method" to the 

defined abbreviation "an FRM"; 

changed "this pmt" to "40 CFR 50, 

incorporated by reference ... Section 

243.1 08"; added "by USEPA and listed 

in" after "and designated"; changed "in 

accordance with pmt 53 of this chapter" 

to "in the List of Designated Methods, 

incorporated by reference in Section 

243.108." 

243.120(b )(1 )(B) 50.7(a)(2) Changed "an equivalent method" to the 

defined abbreviation "an FEM"; added 

"by USEP A and listed in" after "and 

designated"; changed "in accordance 

with pa1t 53 of this chapter" to "in the 

List of Designated Methods, 

incorporated by reference in Section 

243.108." 
243.120(b )(2) 50.7(b) Changed "annual primary and secondary 

PM2.

5 standards are" to singular "1997 

primary and secondary annual average 

NAAQS for PM2.5 is"; changed "this 

part" to "40 CFR 50, incorporated by 

reference ... Section 243.108"; changed 

"micrograms per cubic meter" to the 

defined te1m "11g/m3

." 

243.120(b )(3) 50.7(c) Changed "24-hour primary and 

secondary PM2.5 standards are" to 

singular "1997 primary and secondary 

24-hour NAAQS for PM2.s is"; changed 

"this pm1" to "40 CFR 50, incorporated 

by reference ... Section 243.108"; 

changed "micrograms per cubic meter" 

to the defined te1m "11g/mh 

243.120(b) Board note 50.7 generally Added explanation of the derivation of 

subsection (b); added explanations of the 

differences between the 1997 and 2006 

NAAQS for PM2.5 and Board retention 

of the 1997 NAAQS for PM2.s243.120(c) 50.13 heading Changed "national primary and 

secondm-y ambient air quality standards 

for PM2.s" to singular "2006 primm·y and 

secondary annual average and 24-hour 

NAAQS for PM2.s-" 
243.120(c)(1) 50.13(a) Changed "national primary and 

secondary ambient air quality standards 

for particulate matter are ... annual 

arithmetic mean concentration, and ... 

24-hour average concentration" to "2006 

primary and secondary annual average 

NAAQS for pat1iculate matter is ... , 

annual arithmetic mean concentration, 

and the 2006 p1imary and secondary 24-

hour NAAQS for PM10 is ... , 24-hour 

average concentration,"; changed 

"micrograms per cubic meter (J.tg/m3

)" 

to the defined term "J.tg/m3

"; removed 

the parenthetical "(particles with an 

aerodynamic diameter less than or equal 

to a nominal2.5 micrometers)," which 

has become the basis for a definition of 

"PM25" in Section 243.101 (see the 

entry above in this Table 1 ); changed 

"either" to "by a method that fulfills the 

either of following requirements." 

243.120( c)(! )(A) 50.13(a)(1) Changed "a reference method" to the 

defined abbreviation "an FRM"; 

changed "this pat1" to "40 CFR 50, 

incorporated by reference ... Section 

243.108"; added "byUSEPA and listed 

in" after "and designated'"; changed "in 

accordance with pat153 of this chapter" 

to "in the List of Designated Methods, 

incorporated by reference in Section 

243.108." 

243.120( c)(! )(B) 50.13(a)(2) Changed "an equivalent method" to the 

defined abbreviation "an FEM"; added 

"by USEP A and listed in" after "and 

designated"; changed "in accordance 

with pat153 of this chapter" to "in the 

List of Designated Methods, 

incorporated by reference in Section 

243.108." 
243.120(c)(2) 50.13(b) Changed "annual primmy and secondary 

PM2.5 standards are" to singular "2006 

primmy and secondary annual average 

NAAQS for PM25 is"; changed "this 

pmi" to "40 CFR 50, incorporated by 

reference ... Section 243.108." 

243.120(c)(3) 50.13(c) Changed "24-hour primary and 

secondary PM2.5 standards are" to 

singular "2006 primaty and secondary 

24-hourNAAQS for PM2_5 is"; changed 

"this pmi" to "40 CFR 50, incorporated 

by reference ... Section 243.108." 

243.120(c) Board note 50.13 generally Added explanation of the derivation of 

subsection (c). 

243.122 50.4, 50.5, and 50.17 Replaced the existing language of this 

generally Section with that of the cotTesponding 

federal regulations. 

243.122(a) 50.4 heading Changed "national primary ambient air 

quality standards" to "1971 prin1ary 

annual average and 24-hour NAAQS"; 

added "as" before and "(S02)" as a 

defined abbreviation after "sulfur 

dioxide." 

243.122(a)(l) 50.4(a) Changed "standard" to "1971 primary 

annual average NAAQS for sulfur 

oxides"; changed "parts per million 

(ppm)" to the defmed tenn "ppm"; 

changed "shall" to "must" (twice). 

243.122(a)(2) 50.4(b) Changed "standard" to "1971 ptimary 

24-hour NAAQS for sulfur oxides"; 

ch311ged "pmis per million (ppm)" to the 

defined tenn "ppm"; changed "shall" to 

"must" (three times). 
243.122(a)(3) 50.4(c) Changed "shall" to "tnust"; changed 

"sulfur dioxide" to the defined 

abbreviation "S0

2"; changed "reference 

method" to the defined abbreviation 

"FRM"; changed "appendix A" to 

"appendix A-2"; changed "this part" to 

"40 CFR 50, incorporated by reference 

... Section 243.108"; changed "an 

equivalent method" to the defined 

abbreviation "an FEM"; added "by 

USEP A and listed in" after "and 

designated"; changed "in accordance 

with part 53 of this chapter" to "in the 

List of Designated Methods, 

incorporated by reference in Section 

243.108." 

243.122(a)(4) 50.4(d) Changed "shall" to "must" (four times); 

changed "18, 19, 20, 21, 22, or 23 

hourly averages" to "18-, 19-,20-,21-, 

22-, or 23-hour averages"; changed 

"using 18, 19, etc." to "using the number 

of hours (i.e., 18, 19, etc.)"; removed 

"then" fi·om before "this must be 

considered." 

243.122(a)(5) 50.4(e) Changed "standards ... remain" to 

"1971 primary annual average and 24-

hour NAAQS for sulfur oxides ... 

remain"; changed "S02 national ambient 

air quality standards (NAAQS)" to "the 

2010 primary one-hour NAAQS for 

sulfur oxides"; changed "the so2 

NAAQS ... will no longer apply ... "to 

"the Board will delete the 1971 p1imary 

annual average and 24-hour NAAQS for 

sulfur oxides ... after fulfillment of the 

conditions recited by USEP A in 

corresponding 40 CFR 50.4(e)" and 

deleted all following material. 
243.122(a)(5) Board 50.4(e) generally Added explanation of the continuing 

note applicability of the 1971 primary annual 

average and 24-hour NAAQS for sulfur 

oxides, including suppmting citations to 

USEP A regulations and publicly 

available documents and an explanation 

that the Board will remove the 1971 

primary annual average and 24-hour 

NAAQS when the conditions of 40 CFR 

50.4(e) have clearly been fulfilled. 

243.122(a) Board note 50.4 generally Added explanation of the derivation of 

subsection (a). 

243.122(b) 50.5 heading Changed "national secondary ambient 

air quality standard" to "1971 secondmy 

three-hour NAAQS"; added "as" before 

and "(S02)" after "sulfur dioxide." 

243.122(b)(l) 50.5(a) Changed "3-hour standard" to "1971 

secondary three-hour NAAQS for sulfur 

oxides"; changed "parts per million 

(ppm)" to the defined tetm "ppm"; 

changed "3-hour" to written "threehour" (twice); changed "shall" to "must" 

(three times); changed "nonoverlapping" 

to hyphenated "non-overlapping"; 

changed Hl" to written "one." 

243.122(b)(2) 50.5(b) Changed "shall" to "must"; changed 

"sulfur dioxide" to the defined 

abbreviation "S02"; changed "reference 

method" to the defmed abbreviation 

"FRM"; changed "appendix A" to 

"appendix A-2"; changed "this part" to 

"40 CFR 50, incorporated by reference 

... Section 243.108"; changed "an 

equivalent method" to the defined 

abbreviation "an FEM"; added "by 

USEP A and listed in" after "and 

designated"; changed "in accordance 

with paJt 53 of this chapter" to "in the 

List of Designated Methods, 

incorporated by reference in Section 

243.108." 
243.122(b)(3) 50.5(c) Changed "3-hour" to wtitten "tln·eehour" (six times); changed "shall" to 

"must" (tln·ee times); removed "then" 

from before "this must be considered"; 

changed "3" to written "three." 

243.122(b) Board note 50.5 generally Added explanation of the derivation of 

subsection (b). 

243.122(c) 50.17 heading Changed "national primary and 

secondary ambient air quality standards 

for sulfur oxides (sulfur dioxide)" to 

"1987 primmy and secondary NAAQS 

for PM10. 

, 

243.122(c)(l) 50.17(a) Changed "national primmy !-hour 

annual ambient air quality standard for 

oxides of sulfur" to "20 I 0 primary onehour NAAQS for sulfur oxides"; 

changed "patts per billion (ppm, which 

is I pmt in I ,000,000,000)" to the 

defined tetm "ppb"; changed "sulfur 

dioxide (S02)" to the defined 

abbreviation "S02." 

243.122(c)(2) 50.17(b) Changed "!-hour primary ambient 

standard" to "20 I 0 one-hour primary 

NAAQS for sulfur oxides"; changed "Ihour" to written ~'one-hour"; changed 

"this pmt" to "40 CFR 50, incorporated 

by reference ... Section 243.108." 

243.122(c)(3) 50.17(c) Changed "standard" to "2010 one-hour 

primary NAAQS for sulfur oxides"; 

changed "appendix A or A-1" to 

"appendix A-I or A-2"; changed "this 

pmt" to "40 CFR 50, incorporated by 

reference ... Section 243.108"; changed 

"a Federal Equivalent Method (FEM)" 

to the defined abbreviation "an FEM"; 

added "by USEP A and listed in" after 

"and designated"; changed "in 

accordance with part 53 of this chapter" 

to "in the List of Designated Methods, 

incorporated by reference in Section 

243.108." 
243.122(c) Board note 50.17 generally Added explanation of the derivation of 

subsection (a); added explanation of the 

continued effect of the 1971 primary 

NAAQS for sulfur oxides in subsection 

(a). 

243.123 heading 50.8 heading Retained the pre-existing heading 

~'carbon monoxide." 

243.123 50.8 generally Replaced the existing language ofthis 

Section with that of the conesponding 

federal regulation. 

243.123(a) 50.8(a) Changed "national primary ambient air 

quality standards" to "1971 eight-hour 

and one-hour primary NAAQS"; added 

"as follow." 

243.123(a)(l) 50.8(a)(l) Changed "an 8-hour average 

concentration" to w1itten "an eight-hour 

average concentration of' and moved to 

the begirming of subsection (a)(!); 

changed "parts per million" to the 

defined abbreviation "ppm"; changed 

"milligrams per cubic meter" to the 

defined abbreviation "mg/m3

"; added a 

comma before "not to be exceeded" to 

offset the parenthetical. 

243.123(a)(2) 50.8(a)(2) Changed "a !-hour average 

concentration" to written "an eight-hour 

average concentration of' and moved to 

the beginning of subsection (a)(2); 

changed "par1s per million" to the 

defined abbreviation "ppm"; changed 

"milligrams per cubic meter" to the 

defined abbreviation "mg/m3

"; added a 

comma before "not to be exceeded" to 

offset the parenthetical. 

243.123(b) 50.8(b) Changed "shall" to "must"; added "a 

method that fulfills either of the 

following requirements." 
243.123(b)(l) 50.8(b )(1) Changed "a reference method" to the 

defined abbreviation "an FRM"; added 

"of 40 CFR 50, incorporated by 

reference ... Section 243.108"; added 

"by US EPA and listed in" after "and 

designated"; changed "in accordance 

with part 53 of this chapter" to "in the 

List of Designated Methods, 

incorporated by reference in Section 

243 .I 08"; changed the ending comma to 

a semicolon. 

243.123(b )(2) 50.8(b)(2) Changed "an equivalent method" to the 

defined abbreviation "an FEM"; added 

"by USEP A and listed in" after "and 

designated"; changed "in accordance 

with patt 53 of this chapter" to "in the 

List of Designated Methods, 

incorporated by reference in Section 

243.108." 

243.123(c) 50.8(c) Changed "8-hour" to w1itten "eighthour" (three times); changed "average" 

to "average concentration"; changed 

"shall" to "must" (twice); changed "six 

(or seven) hourly averages" to "six-hour 

(or seven-hour) averages"; changed "75 

percent of the hourly average ... are 

available" to "75 percent of the hourly 

average ... is available." 

243.123(d) 50.8(d) Corrected the spelling "compatision" to 

"comparison"; changed "shall" to 

"must" (twice); changed "pa1ts per 

million" to the defined term "ppm." 

243.123 Board note 50.8 generally Added explanation of the de1ivation of 

Section 243.123. 

243.124 50.11 generally Replaced the existing language of this 

Section with that of the cmresponding 

federal regulations. 

243.124 heading 50.11 heading Changed "national primary ambient air 

quality standards" to singular "nitrogen 

oxides (nitrogen dioxide as indicator)." 
243.124(a) 50.ll(a) Changed "national primary ambient air 

quality standard for oxides of nitrogen" 

to "1971 primary annual average 

NAAQS for nitrogen oxides"; changed 

"pm1s per billion" to the defmed 

abbreviation "ppb"; added "(N02)" as a 

defined abbreviation after "nitrogen 

dioxide." 

243.124(b) 50.ll(b) Changed "national primary !-hour 

ambient air quality standard for oxides 

of nitrogen" to singular, written, and 

with defined abbreviations "20 1 0 

primary one-hour NAAQS for nitrogen 

oxides"; changed "nitrogen dioxide" to 

the defmed abbreviation "N02." 

243.124(c) 50.ll(c) Changed "national primary ambient air 

quality standard for nitrogen dioxide" to 

singular "1971 secondary annual 

averaae NAAQS for nitroaen oxides"· "' "' , changed "pat1s per billion" to the 

defined abbreviation "ppb"; changed 

"micrograms per cubic meter" to 

"J.Lglm3"; added "measured in the air as 

N02" as a parenthetical offset by a 

comma. 

243.124(d) 50.ll(d) Changed "shall" to "must"; added "in 

subsections (a) through (c) of this 

Section" for enhanced clarity. 

243.124(d)(l) 50.11 ( d)(l) Changed "a reference method" to the 

defined abbreviation "an FRM"; 

changed "this pat1" to "40 CFR 50, 

incorporated by reference ... Section 

243.108"; added "and designated by 

USEP A and listed in the List of 

Designated Methods, incorporated by 

reference in Section 243.108." 
243.124(d)(2) 50.ll(d)(2) Changed "a Federal equivalent method" 

to the defined abbreviation "an FEM"; 

added "by USEP A and listed in" after 

"and designated"; changed "in 

accordance with part 53 of this chapter" 

to "in the List of Designated Methods, 

incorporated by reference in Section 

243.1 08." 

243.124(e) 50.ll(e) Changed "annual primmy standard" to 

"1971 primary annual average NAAQS 

for nitrogen oxides"; added "in 

subsections (a) of this Section" for 

enhanced clarity; changed "this part" to 

"40 CFR 50, incorporated by reference 

... Section 243.1 08." 

243.124(t) 50.1l(t) Changed "!-hour primmy standard" to 

"2010 primary one-hour NAAQS for 

nitrogen oxides"; added "in subsection 

(b) of this Section" for enhanced clarity; 

changed "1-hour" to written "one-hour" 

(twice); changed "this part" to "40 CFR 

50, incorporated by reference ... 

Section 243.108." 

243.124(g) 50.ll(g) Changed "secondary standard" to 

singular "1971 secondary annual 

average NAAQS for nitrogen oxides"; 

added "in subsection (c) of this Section" 

for enhanced clatity. 

243.124 Board note 50.11 generally Added explanation of the derivation of 

Section 243.124. 

243.125 heading 50.9, 50.10, and 50.15 Changed "8-hour ozone" to "ozone" to 

generally accommodate all ozone standards in this 

single provision. 

243.125 50.9, 50.1 0, and 50.15 Replaced the existing language of this 

generally Section with that of the cmTesponding 

federal regulations. 
243.125(a) 50.10 heading Changed "national 8-hour primary and 

secondary ambient air quality standards 

for ozone" to singular "1997 primary 

and secondary eight-hour NAAQS for 

ozone." 

243.125(a)(J) 50.JO(a) Changed "level of the nationalS-hour 

primary and secondary ambient air 

quality standards for ozone" to singular 

"1997 primary and secondary eight-hour 

NAAQS for ozone"; changed "a 

reference method" to the defined 

abbreviation "an FRM"; changed "this 

part" to "40 CFR 50, incorporated by 

reference ... Section 243.108"; added 

"by USEPA" after "and designated"; 

changed "in accordance with part 53 of 

this chapter" to "and listed in the List of 

Designated Methods, incorporated by 

reference in Section 243.108"; changed 

"parts per million (ppm)" to the defined 

abbreviation "ppm"; changed "8-hour" 

to wtitten "eight-hour." 

243.125(a)(2) 50.10(b) Changed "8-hour primary and secondary 

ozone ambient air quality standards are" 

to singular "1997 primary and secondary 

eight-hour NAAQS for ozone is"; ; 

changed "8-hour" to written "eighthour"; changed "this patt" to "40 CFR 

50, incorporated by reference ... 

Section 243.108." 
243.125(a)(3) 50.10(c) Added "USEPA has stated in 

corresponding 40 CFR 50.10(c) that"; 

changed "1997 ozone NAAQS set fmth 

in paragraph (a) of this section" to "1997 

primary and secondary eight-hour 

NAAQS for 

0 3 set forth in subsection 

(b)(l) ofthis Section"; changed "1 year" 

to written "one year"; changed 

designation of the area" to "USEP A 

designation of that area"; changed 

"pursuant to section 107 of the Clean 

Air Act" to "pursuant to 42 USC 7407" 

and moved it from after "NAAQS" to 

follow "designation of that area"; 

changed "2008 ozone NAAQS" to 

"2008 primary and secondary eight-hour 

NAAQS for ozone"· chancred "1997 , "' 

ozone NAAQS" to "1997 primary and 

secondary eight-hour NAAQS for 

ozone"; changed "will continue to 

remain" to "will remain"; removed "the 

promulgation of' fi·om after 

"notwithstanding"; changed "2008 

ozone NAAQS under" to "2008 primary 

and secondary eight-hour NAAQS for 

ozone set fmth in"; added "USEP A" 

before "designation"; changed "the 2008 

ozone NAAQS" to "that 2008 primary 

and secondary eight-hour NAAQS for 

ozone"; moved the statement relative to 

codification of area designations into an 

appended Board note. 

243.125(a)(3) Board 50.10(c) Changed "area designations and 

note classifications with respect to the 1997 

NAAQS are codified" to active-voice 

"USEP A has codified area designations 

and classifications with respect to the 

1997 and 2008 primary and secondmy 

NAAQS for ozone" area moved the 

statement into this Board note; changed 

"40 CFRpmt 81" to "40 CFR 81.314"; 

added a statement relative to future 

removal of the 1997 standards when 

they are clearly obsolete or USEP A 

removes them. 
243.125(a) Board note 50.10 generally Added explanation of the derivation of 

this subsection (b). 

243.125(b) 50.15 heading Changed "national primary and 

secondary ambient air quality standards 

for ozone" to singular "2008 plima1y 

and secondary eight -hour plimary and 

secondary NAAQS for 0 3." 

243.125(b)(l) 50.15(a) Changed "level of the nationalS-hour 

primary and secondary ambient air 

quality standards for ozone" to singular 

"2008 primary and secondary eight-hour 

NAAQS for ozone"; changed "pm1s per 

million (ppm)" to the defmed 

abbreviation "ppm"; changed "8-hour" 

to written "eight-hour"; changed "a 

reference method" to the defined 

abbreviation "an FRM"; changed "this 

pm1" to "40 CFR 50, incorporated by 

reference ... Section 243.108"; added 

"by USEPA" after "and designated"; 

changed "in accordance with pa!1 53 of 

this chapter" to "and listed in the List of 

Designated Methods, incorporated by 

reference in Section 243.108." 

243.125(b)(2) 50.15(b) Changed "8-hour primmy and secondary 

ambient air quality standards" to 

singular "2008 plimary and secondary 

eight-hour NAAQS for ozone"; changed 

''3-year'' to written ''three-year''; 

changed "8-hour" to written "eighthour"; changed "this pm1" to "40 CFR 

50, incorporated by reference ... 

Section 243.1 08." 

243.125(b) Board note 50.15 generally Added explanation of the derivation of 

this subsection (c). 

243.126 50.12 and 50.16 generally Replaced the existing language of this 

Section with that of the corresponding 

federal regulations. 
243.126(a) 50.12 heading Changed "national primary and 

secondmy ambient air quality standards" 

to singulm· "1978 primmy and secondary 

NAAQS." 

243.126(a)(l) 50.12(a) Changed "national primmy and 

secondary ambient air quality standards 

for lead ... are" to singular "the 1978 

ptimary and secondary quarterly average 

NAAQS for lead ... is"; changed "a 

reference method" to the defined 

abbreviation "an FRM"; changed "this 

part" to "40 CFR 50, incorporated by 

reference ... Section 24 3.1 08"; added 

"and designated by USEP A and listed in 

the List of Designated Methods, 

incorporated by reference in Section 

243.108" (twice); changed "equivalent 

method" to the defined abbreviation 

"FEM"; changed "micrograms per cubic 

meter" to the defined abbreviation, 

"J.Lg/m3." 
243.126(a)(2) 50.12(b) Changed "standards" to singular "1978 

NAAQS for lead"; removed "the 

promulgation of' fi·om after 

"notwithstanding"; changed "lead 

national ambient air quality standards 

(NAAQS) in § 50.16" to singular "2008 

primary and secondary NAAQS for lead 

in subsection (b) of this Section" 

(twice); changed "lead NAAQS" to 

"1978 primary and secondaryNAAQS 

for lead"; added "by USEPA" after "and 

designated"; changed "section 107 ofthe 

Clean Air Act" to "42 USC 7407"; 

changed "lead NAAQS set forth in 

§ 50.16" to "2008 primary and 

secondary NAAQS for lead set forth in 

subsection (b) of this Section"; changed 

"lead NAAQS set forth in this section" 

to "the 1978 prin1ary and secondary 

NAAQS for lead"; changed "the 

effective date of§ 50.16" to "January 

12, 2009"; changed "the lead NAAQS" 

to "1978 primary and secondary 

NAAQS for lead"; changed "until that 

area submits, pursuant to section 191 of 

the Clean Air Act, and EPA approves an 

implementation plan" to "until USEP A 

has approved an implementation plan for 

that area pursuant to 42 USC 7415"; 

changed Hand or" to "or." 

243.125(a) Board note 50.12 generally Added explanation of the derivation of 

this subsection (a). 

243.126(b) 50.16 heading Changed "national primary and 

secondary ambient air quality standards" 

to singular "2008 primary and secondary 

NAAQS." 
243.126(b)(l) 50.16(a) Changed "national primary and 

secondary ambient air quality standards 

for lead (Pb) ... are" to singular "the 

2008 primary and secondary NAAQS 

for lead ... is"; changed "micrograms 

per cubic meter" to the defined 

abbreviation "[.lg/m3

"; changed "3-

month" to written "three-month"; 

changed "Pb" to "lead"; added "one of 

the following." 

243.126(b )(I )(A) 50.16(a)(l) Changed "a reference method" to the 

defined abbreviation "an FRM"; 

changed "this pa1i" to "40 CFR 50, 

incorporated by reference ... Section 

243.108"; added "by USEPA and listed 

in" after "and designated"; changed "in 

accordance with part 53 of this chapter" 

to "in the List of Designated Methods, 

incorporated by reference in Section 

243.108." 

243.126(b )(I )(B) 50.16(a)(2) Changed "an equivalent method" to the 

defined abbreviation "an FEM"; added 

"by USEP A and listed in" after "and 

designated"; changed "in accordance 

with part 53 of this chapter" to "in the 

List of Designated Methods, 

incorporated by reference in Section 

243.108." 

243.126(b)(2) 50.16(b) Changed "national primary and 

secondary ambient air quality standards 

for Pb are" to singular "the 2008 

primary and secondary NAAQS for lead 

is"; changed "3-month" to written 

"three-month"; changed "this part" to 

"40 CFR 50, incorporated by reference 

... Section 243.108"; changed 

"micrograms per cubic meter" to the 

defined abbreviation "[.lg/m3

." 

24 3 .126(b) Board note 50.16 generally Added explanation of the derivation of 

this subsection (b). 
243.Table A Table 1 to 50.14(c) Moved the tabulated material from the 

body of the regulations into an appended 

table. 

243.Table A heading Table 1 to 50.14(c) Refmmatted the text fi·mn large and 

heading small caps to standard title text; omitted 

"for data to be used in designations." 

243.Table A column 1 Table 1 to 50.14(c) Omitted "pollutant" and "standard," in 

heading column 1 heading favor of the single entry title "NAAQS"; 

changed "promulgation date" to 

"regulatmy citations"; and replaced the 

virgules separating entiies with hard 

returns. 

243.Table A row 1 Table 1 to 50.14(c) row 1 Changed "PM2.5/24-Hr standard" to 

column 1 enn·y column 1 entry "2006 24-hour PM2_5"; separated the 

name of the NAAQS from the 

parenthetical level by a hard retum; 

added citations to the Illinois and 

coiTesponding federalmles; added the 

Federal Register citation for the 

pertinent notice of adopted mle. 

243.Table A row 1 Table 1 to 50.14(c) row 1 Omitted the marking for endnote "a." 

column 3 entry column 3 enn·y 

243.Table A row 1 Table 1 to 50.14(c) row 1 Omitted the marking for endnote "a." 

column 4 entry column 4 entry 

243.Table A row 2 Table 1 to 50.14(c) row 2 Changed "ozone/8-Hr standard" to 

column 1 enti·y column 1 entry "2008 eight-hour ozone"; separated the 

name of the NAAQS from the 

parenthetical level by a hard retum; 

added citations to the Illinois and 

COITesponding federalmles; added the 

Federal Register citation for the 

pe1tinent notice of adopted mle. 

243.Table A row 2 Table 1 to 50.14(c) row 2 Omitted the marking for endnote "a" 

column 3 entry column 3 entry (twice); changed "occurs" to past-tense 

"occuned"; omitted the marking for 

endnote "b." 
243.Table A row 2 Table I to 50.14(c) row 2 Omitted the marking for endnotes "a" 

colunm 4 entry colunm 4 entry and "1 "; changed "occurs" to past-tense 

"occurred"; omitted the marking for 

endnote "b." 

243.Table A row 3 Table I to 50.14(c) row 3 Changed "N02/I-hour standard" to 

colunm I entry column I enhy "20 I 0 one-hour niu·ogen oxides (as 

N02)"; separated the name of the 

NAAQS from the parenthetical level by 

a hard return; con·ected "80-1 00 PPB, 

final level TBD)" to "(I 00 ppb )"; added 

citations to the Illinois and 

corresponding federalmles; added the 

Federal Register citation for the 

pertinent notice of adopted mle. 

243.Table A row 3 Table I to 50.14(c) row 3 Omitted the marking for endnote "a" 

colunm 3 entry colunm 3 entry (tlu·ee times). 

243.Table A row 3 Table I to 50.14(c) row 3 Omitted the marking for endnote "a" 

colunm 4 enu·y colunm 4 entry (three times). 

243.Table A row 4 Table I to 50.14(c) row 4 Changed "S02/l-hour standard" to 

colunm 1 enu·y colunm I enu·y "2010 one-hour sulfur oxides (as S02)"; 

separated the name of the NAAQS from 

the parenthetical level by a hard return; 

corrected "50-I 00 PPB, final level 

TBD)" to "(75 ppb)"; added citations to 

the Illinois and conesponding federal 

mles; added the Federal Register 

citation for the pertinent notice of 

adopted mle. 

243.Table A row 4 Table I to 50.14(c) row 4 Omitted the marking for endnote "a" 

colunm 3 enuy colunm 3 entry (tlu·ee times); changed "occurs" to pasttense "occmTed"; omitted the marking 

for endnote "b." 

243.Table A row 4 Table I to 50.14(c) row 4 Omitted the marking for endnote "a" 

colunm 4 enhy colunm 4 entry (tlu·ee times); changed "occurs" to pasttense "occuned"; omitted the marking 

for endnote "b." 

243.TableA Table I to 50.14(c), Omitted the endnote explanation of 

endnote a unchanged effective dates since 

publication. 
243.Table A Table 1 to 50.14(c), Omitted the endnote explanation of 

endnote b changed effective dates since 

publication. 

243.Table A Board Table 1 generally and Added explanation of the derivation of 

note note Table A; changed "EPA notes" to 

"USEPA noted"; added "the infmmation 

in" before "this table"; changed "EPA" 

to "that US EPA"; added "USEPA stated 

that" before and "in this table" after "the 

general schedule"; changed "used by 

EPA" to "that USEP A will use"; added 

explanation of con·ection of USEP A 

eiTors in the entries for the 2010 onehourNAAQS for sulfur oxides and 2010 

one-hour NAAQS for nitrogen oxides; 

added explanation of omission of 

endnotes "a" and "b." 

Table 2: 

Board Housekeeping Amendments 

Section Source Revision(s) 

243 table of contents, Board Changed "Preamble" to "Scope" to agree with 

24 3.1 02 heading conesponding 40 C.F.R. 50.2. 

24 3 table of contents, Board Added the parenthetical "(Repealed)" to accommodate 

243.104 heading repeal of this Section, which has no direct counterpart in 

40 C.F.R. 50. 

243 table of contents, Board Added the parenthetical "(Repealed)" to accommodate 

243.106 heading repeal of this Section, which has no direct counterpmt in 

40 C.F.R. 50. 

24 3 table of contents, Bom·d Changed "8-Hour Ozone" to "Ozone" to accommodate 

243.122 heading consolidation of conesponding 40 C.F.R. 50.9, 50.1 0, 

and 50.15 into a single provision. 

243 table of contents, Board Changed "Nitrogen Dioxide" to "Nitrogen Oxides 

243.122 heading (Nitrogen dioxide as Indicator)" to more closely follow 

the heading of conesponding 40 C.F.R. 50.11. 
243 table of contents, Board Changed "Appendix" to uppercase "APPENDIX" to 

243.Appendix A comport with Illinois Administrative Code codification 

heading requirements as asserted by the Office of the Secretary of 

State; added the parenthetical "(Repealed)" to 

accommodate repeal of this Section, which has no direct 

counterpart in 40 C.F.R. 50. 

243 table of contents, Board Changed "Appendix" to uppercase "APPENDIX" to 

243.Appendix B compmi with Illinois Administrative Code codification 

heading requirements as asseJied by the Office of tbe Secretary of 

State; added the parenthetical "(Repealed)" to 

accommodate repeal of this Section, which has no direct 

counterpart in 40 C.F.R. 50. 

243 table of contents, Board Changed "Appendix" to uppercase "APPENDIX" to 

243.Appendix C compmi with Illinois Administrative Code codification 

heading requirements as asserted by the Office of tbe Secretary of 

State; added the parenthetical "(Repealed)" to 

accommodate repeal of this Section, which has no direct 

counterpmi in 40 C.F.R. 50. 

24 3 authority note Board Changed "Section 10" to "Sections 7.2 and 10"; replaced 

the obsolete Illinois Revised Statutes citation witb the 

cmTent Illinois Compiled Statutes citation. 

243 source note Board Removed the obsolete citations "4 PCB 191" fiom after 

"R71-23" and "46 PCB 125" from after "R80-II." 

243.103 Board Changed passive-voice "are applicable" to "apply." 

243.104 Board Removed the provision relative to non-degradation, in 

order to rely on the language of individual federal antidegradation provisions. 

243.106 Board Removed the provision, which had no direct counterpart 

in 40 C.F.R. 50. 

243.107 Board Removed the word "except," which does not exist in tbe 

COITesponding text of 40 C.F.R. 50.3; changed "25°C" to 

"5° C." See the entry for this provision in Table I above. 

243.102 generally Board Replaced the existing language of this Section with the 

incorporations by reference that are necessary to support 

a regulation that is identical-in-substance with the federal 

NAAQS regulations; reformatted the incorporations by 

reference so that individual incorporations by reference 

are no longer independently numbered. 
243.102 Board Added the listing of documents available from this 

"Government source, including appendices A-1, A-2, B, C, D, F, G, H, 

Printing Office" J, K, L, N, 0, P, Q, R, S, and T of 40 C.F.R. 50 for the 

purposes of the provisions cited in each entry. 

243.102 Board Added explanation of on-line availability of the 

"Govemment documents. 

Printing Office" 

Board note 

243.102 "USEPA, Board Added the listing of the document available from this 

National Exposure source, "List of Designated Reference and Equivalent 

Research Methods," for the purposes of the provisions cited in the 

Laboratory" ent1y. 

243.102 "USEPA, Board Added the listing of the document available fi-om this 

National Exposure source, "List of Designated Reference and Equivalent 

Research Methods," for the pmposes of the provisions cited in the 

Laboratory" ent1y; added a statement that this reference includes no 

Federal Register notices that approved methods after the 

date of the referenced version of the List. 

243.102 "USEPA, Board Added explanation of on-line availability of the 

National Exposure documents. 

Research 

Laboratory" Board 

note 

243.122 heading Board Changed "Nitrogen Dioxide" to "Oxides of Nitrogen 

(Nitrogen dioxide as Indicator)" to more closely follow 

the heading of conesponding 40 C.F.R. 50.11. 

243.Appendix A Board Changed "Appendix" to uppercase "APPENDIX" to 

heading comport with Illinois Administrative Code codification 

requirements as asse1ted by the Office of the Secretary of 

State; added the parenthetical "(Repealed)" to 

accommodate repeal of this Section, which has no direct 

counterpart in 40 C.F.R. 50. 

243.Appendix A Board Repealed the obsolete 1ules conversion table. 
243.Appendix B Board Changed "Appendix" to uppercase "APPENDIX" to 

heading comport with Illinois Administrative Code codification 

requirements as asse1ied by the Office of the Secretary of 

State; added the parenthetical "(Repealed)" to 

accommodate repeal of this Section, which has no direct 

counte1pa1i in 40 C.F.R. 50. 

243.Appendix B Board Repealed the obsolete !Uies conversion table. 

243.Appendix C Board Changed "Appendix" to uppercase "APPENDIX" to 

heading compmi with Illinois Administrative Code codification 

requirements as asserted by the Office of the Secretary of 

State; added the parenthetical "(Repealed)" to 

accommodate repeal of this Section, which has no direct 

counterpart in 40 C.F.R. 50. 

243.Appendix C Board Repealed the obsolete past compliance dates table. 

Table 3: 

Revisions to the Text of the Proposed Amendments in Final Adoption 

Section Source Revision(s) 

243.101 JCAR Changed "such standard" to "such NAAQS." 

"exceedance of a 

NAAQS" 

243.101 JCAR Changed "the event is an event caused" to "the event is 

"exceptional caused." 

event" 

243.1 01 "federal JCAR Added the definite miicle to "included in the List of 

equivalent Designated Methods." 

method" 

243 .I 0 I "federal JCAR Added the definite article to "included in the List of 

equivalent Designated Methods." 

method" Board 

note 

243.101 "federal JCAR Added the defmite article to "included in the List of 

reference method" Designated Methods." 

243.101 "federal JCAR Added the definite article to "included in the List of 

reference method" Designated Methods." 

Board note 
243.101 "National JCAR Changed "applies for outdoor air" to "applies to outdoor 

Ambient Air air." 

Quality Standard" 

243.101 "parts per JCAR Removed the parenthetical "(immediately below)." 

billion" 

243.10 I "parts per JCAR Removed "and that for 'parts per billion' (immediately 

million" below)." 

243.101 JCAR Changed "in segments of text" to "in text." 

"USEPA" 

243.101 Board JCAR Corrected "C.F.R." to "CFR." 

note 

243.102(b) JCAR Changed "such standards" to "these standards." 

243.105(a)(l) JCAR Changed "such event" to "the event." 

243.105(a)(2) JCAR, Con·ected "paragraph (c)(3)(D) of this section" to 

Board "subsection (c)(3)(D) of this Section." 

243.105(b)(l) JCAR Capitalized "Events" in the topical subheading. 

243.105(b)(2) JCAR, Capitalized "Displays" in the topical subheading; 

Board capitalized "State"; changed "such data" to "these data"; 

changed "this mle" to "this Section"; changed "such use" to 

"the use"; 

243.105(b)(3) JCAR, Capitalized "Fires" in the topical subheading; changed 

Board "such emissions" to "the emissions"; capitalized "State"; 

changed ~'a S:MP" to "an SMP." 

243.105(b) Board Board Added a comma before "and (b)(3)" to offset the final 

note element of a series. 

243.105(c)(l) JCAR Capitalized "Notification" in the topical subheading; 

removed the statutory citation "[415 ILCS 5/4(g) or (r)]"; 

changed "which" to "that" for a restrictive relative clause. 

243.105(c)(2) JCAR Capitalized "Data" in the topical subheading. 

243.1 05( c)(2)(A) JCAR Corrected "one of more measured exceedance" to "one or 

more measured exceedances." 
243.105( c)(2)(B) JCAR Changed "until after USEPA notifies" to "until USEP A 

notifies." 

243.1 05( c)(2)(C) JCAR Changed "July lst" to "July!." 

243.1 05( c)(2)(F) JCAR Changed "Table A to this Pmt" to "Table A ofthis Pmt" 

changed the subsequent reference, 'Table A to this Pmt" to 

"Table A." 

243.105(c)(3) JCAR Capitalized "Demonstrations" in the topical subheading. 

243.1 05( c)(3)(A) JCAR Moved "to USEP A" from after "demonstration" to follow 

"must submit"; added a comma before "along with its 

demonstration" for a parenthetical clause. 

243.1 05( c)(3)(C) JCAR Cmrected "subsection (c)(3)(B)" to "subsection (c)(3)(C)"; 

corrected "40 CFR 50.!4(b)(3)(ii)" to "40 CFR 

50.14(b)(3)(iii)." 

243 .I 08(b ), JCAR Removed the parenthetical "(see below)." 

"Appendix B to 

40 CFR 50" 

243 .I 08(b ), JCAR Corrected "243.125" to "Section 243.125." 

"Appendix I to 40 

CFR 50" 

243.!08(b), JCAR Conected "243.125" to "Section 243.125." 

"Appendix P to 

40 CFR 50" 

243 .I 08(b ), JCAR Cmrected "243.125" to "Section 243.125." 

"Appendix S to 

40 CFR 50" 

243.120(a) JCAR Capitalized "Primary," "Secondary," and "24-Hour" in the 

topical subheading. 

243.120(a)(3)(A) JCAR Changed the ending comma to a semicolon. 

243.120(a)Board JCAR Corrected "(Dec. 22, I 000)" to "(Dec. 22, 2000)." 

note 

243.120(b) JCAR Capitalized "Primaty," "Secondary," ~'Annual," "Average," 

and "24-Hour" in the topical subheading. 
243.120(b )(1 )(A) JCAR Added a comma after "incorporated by reference in Section 

24 3.1 08" to complete offsetting the parenthetical; added the 

definite at1icle to "included in the List of Designated 

Methods." 

243.120(b )(1 )(B) JCAR Added the definite at1icle to "included in the List of 

Designated Methods." 

243.120(c) JCAR Capitalized "Primary," "Secondary," '"Annual," "Average," 

and "24-Hour" in the topical subheading. 

243.120( c)(l )(A) JCAR Added a comma after "incorporated by reference in Section 

243.108" to complete offsetting the parenthetical; added the 

definite at1icle to "included in the List of Designated 

Methods." 

243.120( c)(l )(B) JCAR Added the definite article to "included in the List of 

Designated Methods." 

243.120(c) Board Board CotTected the indent level of the note to correspond with its 

note associated subsection (c). 

243.122(a) JCAR Capitalized ''Primaty," "Annual," "Average," "24-Hour," 

"Sulfur" (twice), "Oxides, and "Dioxide" in the topical 

subheading. 

243.122(a)(3) JCAR Added the defmite article to "included in the List of 

Designated Methods." 

243.122(a)(4) JCAR Removed "then" from before "this must be considered." 

243.122(a)(5) JCAR Corrected "the 1971 primary annual average and 24-hour 

NAAQS for sulfur oxides ... remains" to "the 1971 

primary annual average and 24-hour NAAQS for sulfur 

oxides ... remain." 

243.122(a) Board Board Added "this subsection (a) is derived from 40 CFR 50.4 

note (2012)." 

243.122(b) JCAR Capitalized "Secondary," "Tlu·ee-Hour," "Sulfur," and 

"Oxides in the topical subheading. 

243.122(b)(3) JCAR Removed "then" from before "this must be considered." 

243.122(b) Board Board Conected the indent level of the note to cotTespond with its 

note associated subsection (b). 
243.122(c) JCAR Capitalized "Primary," "One-Hour," "Sulfur," and "Oxides 

in the topical subheading. 

243.122(c)(3) JCAR Corrected "a FRM" to "an FRM"; changed the em-dash in 

"A-2" to an en-dash in "A-2"; corrected "a FEM" to "an 

FEM." 

243.123(a) JCAR Changed "as follow" to "as follows." 

243.123(b)(l) JCAR Added the definite m1icle to "included in the List of 

Designated Methods"; changed the ending conuna to a 

semicolon. 

243.123(b)(2) JCAR Added the definite article to "included in the List of 

Designated Methods." 

243.123(c) JCAR Changed "75 percent of the hourly average ... are 

available" to "75 percent of the hourly average ... is 

available." 

243 .124( d)( I) JCAR Con·ected "a FRM" to "an FRM"; added the definite article 

to "included in the List of Designated Methods." 

243.124( d)(2) JCAR Changed "Federal FEM" to "FEM"; added the definite 

micle to "included in the List of Designated Methods." 

243.124(e) JCAR Changed to lower-case "appendix S or 40 CFR 50"; added a 

comma after "incorporated by reference in Section 243.108" 

to complete offsetting the pm·enthetical. 

243.124(f) JCAR Changed to lower-case "appendix S or 40 CFR 50"; added a 

comma after "incorporated by reference in Section 24 3 .I 08" 

to complete offsetting the parenthetical. 

243.125(a) IERG, Removed the proposed subsection (a), which contained the 

Board 1979 primary and secondary one-hour NAAQS for ozone, 

and renumbered proposed subsection (b) as subsection (a); 

capitalized "Primmy," "Secondary," "Eight-Hour," and 

"Ozone" for the topical heading. 

243.125(a)(l) JCAR CmTected "a FRM" to "an FRM"; added a comma after 

"incorporated by reference in Section 243.108" to complete 

offsetting the parenthetical; added the definite m1icle to 

"included in the List of Designated Methods." 
243.125(a)(3) Board Con·ected the "the 1997 and 2008 primary and secondary 

Board note IERG NAAQS for ozone" to "the 2008 primary and secondary 

NAAQS for ozone"; conected "40 CFR 50.9 or 50.1 0" to 

"40 CFR 50.10"; corrected "subsections (a) and (b)" to "this 

subsection (a)." 

243.125(a) Board Board Changed "this subsection (b)" to "this subsection (a)." 

note IERG 

243.125(b) IERG, Removed the proposed subsection (a), which contained the 

Board 1979 primary and secondary one-hour NAAQS for ozone, 

and renumbered proposed subsection (c) as subsection (b); 

capitalized "Primmy," "Secondary," "Eight-Hour," and 

"Ozone" for the topical heading. 

243.125(b)(l) JCAR Added the definite article to "included in the List of 

Designated Methods" (twice); added a conuna after 

"incorporated by reference in Section 243.1 08" to complete 

offsetting the parenthetical. 

243.125(b) Board Board Conected the indent level of the note to conespond with its 

note IERG associated subsection (b); changed "this subsection (c)" to 

"this subsection (b)." 

243.125(c) Board Board Conected the indent level of the note to con·espond with its 

note associated subsection (c); changed "this subsection (c)" to 

"this subsection (b)." 

243.126(a) IERG, Capitalized "Primmy," "Secondary," "Qumterly," 

Board "Average," and "Lead" for the topical heading. 

243.126(a)(l) JCAR Added the definite article to "included in the List of 

Designated Methods" (twice); changed "micrograms per 

cubic meter" to the defined abbreviation, "J.Lg/m3

." 

243.126(a)(2) JCAR CmTected "this subsection" to "this subsection (a)." 

243.126(a) IERG, Capitalized "Plimary," "Secondm·y," "Three-Month," 

Board "Average," and "Lead" for the topical heading. 

243.126(a) Board Board Co!Tected the indent level of the note to conespond with its 

note associated subsection (a). 
243.126(b )(!)(A) JCAR Changed to lower-case "appendix G of 40 CFR 50"; added 

a comma after "incorporated by reference in Section 

243.1 08" to complete offsetting the parenthetical; added the 

definite article to "included in the List of Designated 

Methods." 

243.126(b )(!)(B) JCAR Added the definite article to "included in the List of 

Designated Methods." 

243.126(b )(1 )(A) JCAR Changed to lower-case "appendix R of 40 CFR 50." 

243.126(b) Board Board CmTected the indent level of the note to co!Tespond with its 

note associated subsection (b). 

243.Appendix A JCAR Removed underlining from the Section heading; removed 

heading the overstruck fmmerly centered table headings, "Appendix 

A" and "Rule into Section Table." 

243.Appendix B JCAR Removed underlining from the Section heading; removed 

heading the overstmck formerly centered table headings, "Appendix 

B" and "Section into Rule Table." 

243.Appendix C JCAR Removed underlining from the Section heading; removed 

heading the overstruck fmmerly centered table headings, "Appendix 

C" and "Past Compliance Dates." 

Table 4: 

Requested Revisions to the Text of the Proposed Amendments Not Made in 

Final Adoption 

Section Affected Source of Request: Requested Explanation 

Revision 

243 authority note JCAR: Remove the cmmna before The Board consistently uses a 

"and 2 7" in the citation. comma to offset the fmal element of 

a senes. 

243.101 JCAR: Change the smart quotes The Board consistently uses smart 

generally to straight quotes tln·oughout (92 quotes. 

occu!Tences ). 

243.101 "federal JCAR: Change "which is The Board prefers to use "which" 

equivalent included" to "that is included." for a subsequent restrictive relative 

method" clause. 
243.101 "federal JCAR: Change "which is The Board prefers to use "which" 

reference method" included" to "that is included." for a subsequent restJ.ictive relative 

clause. 

243.105(a) JCAR: Remove the petiod at the All other topical headings that begin 

end of the one-word topical a subsection use the period, and the 

heading, "Requirements." Board believes the period is 

appropriate where the topical 

heading is not followed by text 

within the same subsection. 

243.!05(b)(l) JCAR: Change "where the Cmresponding 40 C.F.R. 

Agency has demonstrated" to 50.!4(b)(l) uses "where," which is 

"when the Agency has appropriate with a situational 

demonstrated." condition, rather than a condition in 

time. 

243.105(b)(2) JCAR: Change "where the Corresponding 40 C.F.R. 

Agency has demonstrated" to 50.14(b )(2) uses "where," "which" 

"when the Agency has is appropriate with a situational 

demonstrated." condition, rather than a condition in 

time. 

243.105(b)(2) JCAR: Change remove the The Board prefers to use a comma 

comma from before "or other to offset the final element of a 

cultural events." seties. 

243.105(b)(2) JCAR: Change "which satisfy" to The Board prefers to use "which" 

"that satisfy." for a subsequent restrictive relative 

clause. 

243.105(b)(3) JCAR: Change "where the Corresponding 40 C.F.R. 

Agency has demonstrated" to 50.14(b )(3) uses "where," "which" 

"when the Agency has is approptiate with a situational 

demonstJ.·ated." condition, rather than a condition in 

time. 

243.105(b)(3) JCAR: Change the smart The Board prefers use of the smart 

apostrophe in "State's" to a apostrophe. 

s1J.·aight apos1J.·ophe. 

243.!05(c)(l) JCAR: Change "where the Cmresponding 40 C.F.R. 

Agency has delegated" to "when 50.14(c)(l) uses "where," "which" 

the Agency has delegated." is appropriate with a situational 

condition, rather than a condition in 

time. 
243.105(c)(1) JCAR: Change the sma1t The Board prefers use of the sma1t 

apostrophe in "State's" to a apostrophe. 

straight apostrophe. 

243.105(c)(l) JCAR: Remove the period at the All other topical headings that begin 

end of the topical heading, a subsection use the period, and the 

"Flagging of Data." Board believes the period is 

appropriate where the topical 

heading is not followed by text 

within the same subsection. 

243.1 05( c)(2)(B) JCAR: Change the smart The Board prefers use of the smart 

apostrophe in "State's" to a apostrophe. 

straight apostrophe. 

243.1 05( c)(2)(B) JCAR: Change "subsection (c)(3) The Board has consistently added 

of this Section" to "subsection "of this Section" for several years at 

(c)(3)." the instruction of the Code Unit and 

I CAR. The Board would prefer 

confinnation and consideration of 

this suggested stylistic revision 

before making it. 

243.1 05( c)(2)(C) JCAR: Change "subsection The Board has consistently added 

(c)(2)(D) or (c)(2)(E) of this "of this Section" for several years at 

Section" to "subsection (c)(2)(D) the instruction of the Code Unit and 

or (c)(2)(E)." JCAR. The Board would prefer 

confim1ation and consideration of 

this suggested stylistic revision 

before making it. 

243.1 05( c)(2)(F) JCAR: Change "a NAAQS" to The acronym is actually pronounced 

"an NAAQS." as a word, making aa" more 

appropriate. 

243.1 05( c)(3)(D)- JCAR: Change the smart quotes The Board consistently uses smmt 

(i) to straight quotes throughout (two quotes. 

occmTences ). 

243.1 08(b ), "List JCAR: Change the smmt quotes The Board consistently uses smmt 

of Designated ... to straight quotes (four quotes. 

Methods" occmTences ). 
243.120(a) JCAR: Remove the period at the All other topical headings that begin 

end of the topical heading, "1987 a subsection use the period, and the 

Primary and Secondary 24-Hour Board believes the period is 

NAAQS for PM10." appropriate where the topical 

heading is not followed by text 

within the same subsection. 

243.120(a)(l) JCAR: Change the smatt quotes The Board consistently uses smart 

to straight quotes (two quotes. 

occunences). 

243.120(b) JCAR: Remove the period at the All other topical headings that begin 

end of the topical heading, "1997 a subsection use the period, and the 

P1immy and Secondary Annual Board believes the period is 

Average and 24-HourNAAQS for appropriate where the topical 

PM2.s-" heading is not followed by text 

within the same subsection. 

243.120(c) JCAR: Remove the pe1iod at the All other topical headings that begin 

end of the topical heading, "2006 a subsection use the period, and the 

Prima1y and Secondary Annual Board believes the period is 

Average and 24-Hour NAAQS for appropriate where the topical 

PM2.s-" heading is not followed by text 

within the same subsection. 

243.122(a) JCAR: Remove the period at the All other topical headings that begin 

end of the topical heading, "1971 a subsection use the period, and the 

Prima1y Annual Average and 24- Board believes the period is 

Hom NAAQS for Sulfur Oxides appropriate where the topical 

(as Sulfur Dioxide)." heading is not followed by text 

within the same subsection. 

243.122(a)(4) JCAR: Change "subsection (b) of The Board has consistently added 

this Section" to "subsection (b)." "of this Section" for several years at 

the instruction of the Code Unit and 

JCAR. The Board would prefer 

confilmation and consideration of 

this suggested stylistic revision 

before making it. 
243.122(a)(5) JCAR: Change "subsection (c) of The Board has consistently added 

this Section" to "subsection (c)." "of this Section" for several years at 

the instmction of the Code Unit and 

JCAR. The Board would prefer 

confitmation and consideration of 

this suggested stylistic revision 

before making it. 

243.122(a) Board JCAR: Change the web address, The web address is invalid with the 

note "http://www.epa.gov/ mnission of "R5." 

so2designations/recletters/ 

R5 _ IL Jec _ wtechanalysis.pdf' to 

"http://www.epa.gov/ 

so2designations/recletters/ 

_ IL _rec _ wtechanal ysis. pdf." 

243.122(b) JCAR: Remove the period at the All other topical headings that begin 

end of the topical heading, "1971 a subsection use the period, and the 

Secondmy Tlu·ee-Hour NAAQS Board believes the period is 

for Sulfur Oxides (as S02)." appropriate where the topical 

heading is not followed by text 

within the same subsection. 

243.122(b)(3) JCAR: Change "subsection (b )(I) The Board has consistently added 

of this Section" to "subsection "of this Section" for several years at 

(b)(!)." the instmction of the Code Unit and 

JCAR. The Board would prefer 

confitmation and consideration of 

this suggested stylistic revision 

before making it. 

243.122(c) JCAR: Remove the period at the All other topical headings that begin 

end of the topical heading, "20 I 0 a subsection use the period, and the 

Primary One-Hour NAAQS for Board believes the period is 

Sulfur Oxides (as S02)." appropriate where the topical 

heading is not followed by text 

within the same subsection. 

243.122(c) Board JCAR: Change "subsection (a)(5) The Board has consistently added 

note of this Section" to "subsection "of this Section" for several years at 

(a)(5)." the instmction of the Code Unit and 

JCAR. The Board would prefer 

confinnation and consideration of 

this suggested stylistic revision 

before making it. 
243.124(d) JCAR: Change "subsections (a) The Board has consistently added 

through (c) of this Section" to "of this Section" for several years at 

"subsections (a) through (c)." the instmction of the Code Unit and 

JCAR. The Board would prefer 

confitmation and consideration of 

this suggested stylistic revision 

before making it. 

243.124(e) JCAR: Change "subsection (a) of The Board has consistently added 

this Section" to "subsection (a)." "of this Section" for several years at 

the instmction of the Code Unit and 

JCAR. The Board would prefer 

confirmation and consideration of 

this suggested stylistic revision 

before making it. 

243.124(£) JCAR: Change "subsection (b) of The Board has consistently added 

this Section" to "subsection (b)." "of this Section" for several years at 

the instmction of the Code Unit and 

JCAR. The Board would prefer 

confirmation and consideration of 

this suggested stylistic revision 

before making it. 

243.124(g) JCAR: Change "subsection (c) of The Board has consistently added 

this Section" to "subsection (c)." "of this Section" for several years at 

the instmction of the Code Unit and 

JCAR. The Board would prefer 

continuation and consideration of 

this suggested stylistic revision 

before making it. 

243.125(a) JCAR: Remove the period at the All other topical headings that begin 

end of the topical heading, "1997 a subsection use the period, and the 

Primmy and Secondary Eight- Board believes the period is 

Hour NAAQS for Ozone." appropriate where the topical 

heading is not followed by text 

within the same subsection. 

243.125(b )(3) JCAR: Change "subsection (b)(l) The Board has consistently added 

of this Section" to "subsection "of this Section" for several years at 

(b )(1 )"; change "subsection ( c )(1) the instmction of the Code Unit and 

of this Section" to "subsection JCAR. The Board would prefer 

(c)(!)"; change "subsection (c) of confitmation and consideration of 

this Section" to "subsection (c)." this suggested stylistic revision 

before making it. 
243.125(b) JCAR: Remove the period at the All other topical headings that begin 

end of the topical heading, "2008 a subsection use the petiod, and the 

Primary and Secondary Eight- Board believes the period is 

Hour NAAQS for Ozone." appropriate where the topical 

heading is not followed by text 

within the same subsection. 

243.126(a) JCAR: Remove the petiod at the All other topical headings that begin 

end of the topical heading, "1978 a subsection use the period, and the 

Primaty and Secondary Qumterly Board believes the period is 

Average NAAQS for Lead." appropriate where the topical 

heading is not followed by text 

within the same subsection. 

243.126(a)(2) JCAR: Change "subsection (b) of The Board has consistently added 

this Section" to "subsection (b)" "ofthis Section" for several years at 

(three times). the instmction of the Code Unit and 

JCAR. The Board would prefer 

confim1ation a11d consideration of 

this suggested stylistic revision 

before making it. 

243.126(a)(2) JCAR: Change the smm1 quotes The Board consistently uses smmt 

Board note to straight quotes (two quotes. 

occurrences). 

243.126(b) JCAR: Remove the period at the All other topical headings that begin 

end of the topical heading, "2008 a subsection use the period, and the 

Primmy and Secondm·y Three- Board believes the period is 

Month Average NAAQS for appropriate where the topical 

Lead." heading is not followed by text 

within the same subsection. 

ORDER 

The Board directs the Clerk to provide notice in the Illinois Register of the following 

adopted amendments to the Illinois ambient air quality regulations at 35 Ill. Adm. Code 243: 

TITLE 35: ENVIRONMENTAL PROTECTION 

SUBTITLE B: AIR POLLUTION 

CHAPTER 1: POLLUTION CONTROL BOARD 

SUBCHAPTER 1: AIR QUALITY STANDARDS AND EPISODES 

PART243 

AIR QUALITY STANDARDS 
Section 

243.101 

243.102 

243.103 

243.104 

243.105 

243.106 

243.107 

243.108 

Section 

243.120 

243.121 

243.122 

243.123 

243.124 

243.125 

243.126 

SUBPART A: GENERAL PROVISIONS 

Definitions 

PreaHialeScope 

Applicability 

N ondegradation (Repealed) 

Air Quality Monitoring Data Influenced by Exceptional Events 

Monitoring (Repealed) 

Reference Conditions 

Incorporations by Reference 

SUBPART B: STANDARDS AND MEASUREMENT METHODS 

PM10 and PM2.s 

Pm1iculates (Repealed) 

Sulfur Oxides (Sulfur Dioxide) 

Carbon Monoxide 

Nitrogen Oxides (Nitrogen Dioxide as Indicator) 

g Hoar Ozone 

Lead 

f<j'lj'leflEiiJt243.APPENDIX A Rule into Section Table (Repealed) 

Aj'lfleFlaiJl 243.APPENDIX B Section into Rule Table (Repealed) 

Aj'lj'leaEiiJt 243.APPENDIX C Past Compliance Dates (Repealed) 

243.TABLE A Schedule of Exceptional Event Flagging and Documentation Submission 

for New or Revised NAAOS 

AUTHORITY: Implementing geetioa Sections 7.2 and 10 and authorized by Section 27 of the 

Environmental Protection Act (Ill. Rev. Stat 1991, eh. Ill !J2, j'lars. 101 Q aaEII Q27) [ 415 ILCS 

517.2. 10. and 27]. 

SOURCE: Adopted as Chapter 2: Air Pollution, Part III: Air Quality Standards, in R71-23,-4 

PCB 191, flied and effective Aprill4, 1972; amended in R80-ll, 4a PCB 125, at 6 Ill. Reg. 

5804, effective April22, 1982; aJnended in R82-12, at 7 Ill. Reg. 9906, effective August 18, 

1983; codified at 7 Ill. Reg. 13630; amended in R91-35 at 16 III. Reg. 8185, effective May 15, 

1992; amended in R09-19 at 35 Ill. Reg. 18857, effective October 25, 2011; amended in R13-ll 

at 37 Ill. Reg. , effective ________ _ 

SUBPART A: GENERAL PROVISIONS 

Section 243.101 Definitions 

a) EJteej'lt as stat eEl ia this Part aaEI anless a Eliffereat meaaiag of a term is elear from 

its eoflleJll, the Elefinitioas ofterms aseEI ifl this Part shall ae the same as those 

aseEI ia the Ea-virofl!flefllal Proteetioa Aet [415 ILCS 5] (Aet). 
ll) All terms tfiat 8flj3ear iH tfiis Part fiave tfie defiHitieHs SJ3eeified lly 35 Ill. Adm. 

Cede ?QJ er 211. 

For the pmposes of this Pmt. te1ms listed below will have the meanings attributed to them in this 

Section. As used in this Pmt. all terms not defined in this Section will have the meaning given 

them by the Act the CAA, incomorated by reference in Section 243.108: or 35 Ill. Adm. Code 

201.102. 

"Act" means the Environmental Protection Act [ 415 ILCS 5]. 

"Agency" means the Illinois Environmental Protection Agency. 

"Ambient air" means that pmtion of the atmosphere. extemal to buildings. to 

which the general public has access. 

"Clean Air Act" or "CAA" means the federal Clean Air Act 42 USC 7401 et. seg. 

as amended. incomorated by reference in Section 243.108. 

"Exceedance of a NAAQS" means one occun·ence of a measured or modeled 

concentration that exceeds the specified concentration level of such NAAQS for 

the averaging period specified by the standard. 

"Exceptional event" means an event that fulfills all of the following criteria: 

The event affects air guality: 

The event is not reasonably controllable or preventable: 

The event is caused by human activity that is unlikely to recur at a 

particular location or a natural event: and 

The event is dete1mined by USEPA in accordance with 40 CFR 50.14 to 

be an exceptional event. 

An "exceptional event" does not include any of the following: 

Stagnation of air masses or meteorological inversions: 

A meteorological event involving high temperatures or lack of 

precipitation: or 

Air pollution relating to source noncompliance. 

"Federal eguivalent method" or "FEM" means a method for measuring the 

concentration of an air pollutant in the ambient air that USEP A has designated as 

an eguivalent method pursuant to 40 CFR 53 and which is included in the List of 
Designated Methods. including later updates. as incorporated by reference in 

Section 243.108; the term "federal equivalent method" does not include a method 

for which USEP A has cancelled or superseded an equivalent method designation 

in accordance with 40 CFR 53.11 or 53.16. as reflected in the incorporation by 

reference in Section 243.108. 

BOARD NOTE; De1ived from 40 CFR 50.1 (f) (defmition of "equivalent 

method"). 50.ll(d)(2) (parenthetical defmition of"FEM"). and 53.1 (defmition of 

"federal equivalent method"). The clause "including later updates" in this 

definition is intended to exclude methods canceled by USEP A pursuant to 40 

CFR 53.11 or 53.16 for which the cancellation is included in the updates to List of 

Designated Methods inc01porated by reference in Section 243.108. A federal 

designation of an FEM becomes effective upon publication of a notice in the 

Federal Register. A federal cancellation of an FEM becomes effective upon 

deletion from the listing ofFEMs. 

"Federal reference method" or "FRM" means a method of sampling and 

analyzing the ambient air for an air pollutant that USEPA has specified as a 

reference method in an appendix to 40 CFR 50, inc01porated by reference in 

Section 243.108. or a method that USEPA has designated as a reference method 

pursuant to 40 CFR 53 and which is included in List of Designated Methods. 

including later updates. incorporated by reference in Section 243.1 08; the te1m 

"federal reference method" does not include a method for which USEP A has 

cancelled or superseded a reference method designation in accordance with 40 

CFR 53.11 or 53.16. as reflected in the incorporation by reference in Section 

243.108. 

BOARD NOTE: Derived from 40 CFR 50.l(f) (definition of"reference method") 

and 53 .I (definition of "federal reference method"). The clause "including later 

updates" in this definition is intended to include methods canceled by USEP A 

pursuant to 40 CFR 53.11 or 53.16 for which the cancellation is included in the 

updates to List of Designated Methods incorporated by reference in Section 

243.108. A federal designation of an FRM becomes effective upon publication of 

a notice in the Federal Register. A federal cancellation of an FRM becomes 

effective upon deletion from the listing of FRMs or from an appendix to 40 CFR 

50. 

"Micrograms per cubic meter" or "l!gfln3

" means one millionth (1 o·6

) of a gram of 

a contaminant per cubic meter of ambient air. as measured and dete1mined by the 

methods prescribed for that contaminant. 

BOARD NOTE: The Board added this definition and that for "milligrams per 

liter" (immediately below). 

"Milligrams per cubic meter" or "mg/m3

" means one thousandth (1 0"3) of a gram 

of a contaminant per cubic meter of ambient ai.r. as measured and determined by 

the methods prescribed for that contaminant. 
"National Ambient Air Quality Standard" or "NAAOS" means a standard 

established by USEP A that applies for outdoor air tlu·oughout the United States. 

BOARD NOTE: The Board added this definition. derived from the definition in 

"Terms of Environment: Glossary. Abbreviations, and Acronyms" (December 

1997). EPA 175-B-97-001. at p. 30. USEPA has codified the NAAQS at 40 CFR 

50. 

BOARD NOTE: The Board added this definition based on the definition in 

"Tenus of Environment: Glossarv. Abbreviations. and Acronvms" (December 

1997). document number EPA 175-B-97-001. USEPA. Office of 

Communications. Education. and Public Affairs. at p. 30. 

"Natural event" means an event in which human activity plays little or no direct 

causal role. 

"Pmts per billion" or "ppb" means the ratio of the pmts of a specified contaminant 

to a billion pmts of air by weight (I: I o·9

). as measured and dete1mined by the 

methods prescribed for that contaminant. 

BOARD NOTE: The Board added this definition and that for "pmts per million." 

derived from the parentheticals in 40 CFR 50.4(a) and (b) and 50.17(a) and the 

definition of"pmts per billion (ppb)/pmts per million (ppm)" in "Te1ms of 

Environment: Glossary. Abbreviations. and Acronvms" (December 1997). EPA 

175-B-97-001. at p. 34. 

"Pmts per million" or "ppm" means the ratio of the parts of a specified 

contaminant to a million parts of air by weight (I: 1 0'6

). as measured and 

dete1mined by the methods prescribed for that contaminant. 

BOARD NOTE: The Board added this definition. derived from the parentheticals 

in 40 CFR 50.4(a) and (b) and 50.17(a) and the definition of"pmts per billion 

(ppb)/pmts per million (ppm)" in 'Te1ms of Environment: Glossary. 

Abbreviations. and Acronyms" (December 1997). EPA 175-B-97-001. at p. 34. 

"PM 10" means particulate matter that has an aerodvnamic diameter less than or 

equal to a nominal 10 micrometers Cum). 

BOARD NOTE: The Board added this definition. derived fi'om the parenthetical 

definition in 40 CFR 50.6(c). 

"PM,_s'' means pmticulate matter that has an aerodynamic diameter less than or 

equal to a nominal2.5 micrometers Cum). 

BOARD NOTE: The Board added this defmition. derived fi'om the parenthetical 

definition in 40 CFR 50. 7(a). 

'Traceable" means that a local standard has been compared and ce1tified either 

directly or via not more than one intermediate standard. to a primary standard, 

such as a National Bureau of Standards Standard Reference Material (NBS SRM). 

or a USEP A/NBS-approved Ce1tified Reference Material (CRM). 
"USEPA" means the United States Environmental Protection Agency. 

BOARD NOTE: Derived from 40 CFR 50.1(c). The Board has used "US EPA" 

in text where USEPA has used "Administrator." where action by USEPA is 

clearly contemplated. Othe1wise. the Board has retained the term "Agency" as 

defined in this Section. 

BOARD NOTE: Derived from 40 CFR 50.1 (2012). except as otherwise more specifically 

indicated. 

(Source: Amended at 37 Ill. Reg. ___ , effective---------' 

Section 243.102 Preamble Scope 

a) Air EjUality staRaanls are limits eR atmespherie eeReeRtratieRs ef air eeRiaR'!iRaRis 

establishes fer the pufJ.3ese efpreteetiRg public health aREl welfare. The levels ef 

air EjUality Elesigaatea by the staRElaras are ElesigRea te pre teet agaiRst iRjury te 

humaR, plaRI er arnmallife aRa they a.·e :further iRieREleate allev: maJ<imum 

eRj eymeRI sf life aREl preperty eeRsisteRt with the iRieRI ef the Act. 

a) This Pmt sets forth the NAAOS adopted by USEPA under section 109 of the 

CAA (42 USC 7409) and incorporated into this Part pursuant to 415 ILCS 5/7.2 

and lOCH). 

e) The first use sf eur air reseurees is te sustaiR life. Air eRieriRg the reSJ.3iratery 

tract must Ret meRaee health. Therefere, the air EjUality staRElarEls set must, as a 

millimum, previae air which will Ret aaversely affect, threugh acute er ehrerne 

symptems, the health efthe eommullity. AElverse health effects iReluae Ret eRly 

tHe !30ssiBle flFOElHetioa aeS. aggravatiea of disease, But alse iaterferenee \Vith 

eeaily :fuRetieRs. The staRaaras have alse takeR inte aeeouRI seiliRg, een·esieR, 

vegetatioR Elamage aREl other humaR effects. 

bl National primary ambient air quality standards (primary NAAOSl define levels of 

air quality that USEPA has judged are necessary. with an adequate margin of 

safetv. to protect the public health. National secondary ambient air quality 

standards (secondary NAAOSl define levels of air quality that USEPA has judged 

necessary to protect the public welfare from any known or anticipated adverse 

effects of a pollutant. These standards are subject to revision. and additional 

primary and secondary NAAOS may be promulgated as USEP A deems necessary 

to protect the public health and welfare. 

e) Primary ffiRBieRI air EjUality staRElaras EleHRe levels sf air EjUality which are 

Reeessary, with aR aEle(juate margiR of safety, to protect the public health. 

SeeoRElary arubieRI air EjUality staRElaras EleHRe levels efair EjUality which are 

Reeessary to protect the public vrelfare from aRy kRowR or aRiieipatea adverse 

effects of a pollutaRI. 
c) The promulgation of primmy and secondary NAAOS must not be considered in 

any manner to allow significant dete1ioration of existing air quality in any portion 

of this State. 

El) Tke staRElaras are mere tkaR geals. Tke;· are legally effiereeaele limitatieRs, aRE! 

af!Y J3erseR eaHsmg er eeRtrieHtmg te a vielatiefl ef tee staREiarEls is sH!Jj eet te 

eRfureemeRt j3reeeeEiiRgs HREier tee Aet. Tee staRElarEls have alse seeR ElesigReEi 

fur ase as a easis fer the EiB'<·eleJ3m.eflt ef imj3lemeE&atieR J3lans ey State af!aleeal 

ageReies fur tl>e aeatemeflt aRE! eeRtrel efJ3ellHtaRt emissieRs frem eKistiRg 

seHrees, aRE! fur ilie EletermiRatieR ef air eefltaf!Tiflaflt eRTissieRliR>itatieRs te 

iRSHre tBat j3ej3ti\atieR af!a eeeRemie grewth treRaS ae Ret aaa te the regieR'S air 

J3elh!tieR J3reelems. 

BOARD NOTE: Derived from 40 CFR 50.2 (2012). 

(Source: Amended at 37 Ill. Reg. ____ , effective _________ __) 

Section 243.103 Applicability 

The standards in this Part are 8J3J3lieaele ~tlu·oughout the State of Illinois, except as 

otherwise provided in this Pmt. 

(Source: Amended at 37 Ill. Reg. ____ , effective _________ __) 

Section 243.104 Non degradation (Repealed) 

EllistiRg aRwieflt air EttJality !Bat is setter tkaR !Be estaeliskea ameieflt air EJHality staREiaras at the 

Elate eft6eil: aElej3tieR will ee fllaffitaiReEl ifl its j3reseflt higk EttJality. SHea ameieflt air Ejt!ality 

skall Ret ee lewerea mrless af!a Hfltil it is j3F9Vea te !Be IlliReis Ew<iref!fflefltal PreteetieR AgeRey 

(AgBfle;0 tkat ilie ehaRge is jHstifiaele as a resH!t efReeessary eeeRemie aRE! seeial ae'<eleJ3meflt 

aRE! will Ret iflterfure wit6 er eeeeme iRjHrieHs te kt!maR kealt6 er welfare. 

(Source: Repealed at 37 Ill. Reg. ____ , effective _________ __; 

Section 243.105 Air Qua!itv Monitoring Data Influenced bv Exceptional Events 

a) Requirements. 

I) The Agency may request USEP A to exclude from use in detenninations 

data showing an exceedance of an NAAOS that is directly due to an 

exceptional event. The Agency must demonstrate to USEP A that the 

event caused a specific air pollution concentration at a particular air 

quality monitoring location. 

2) A demonstration to justify data exclusion may include any reliable and 

accurate data, but must demonstrate a clear causal relationship between 
the measured exceedance of an NAAOS and the event in accordance with 

subsection (c)(3)(D) of this Section. 

b) Dete1minations by US EPA. US EPA has stated the criteria for making a 

detem1ination to exclude data as follow: 

I) Exceptional Events. USEP A has stated that it will exclude data fi·om use 

in dete1minations of exceedance of an NAAOS where the Agency has 

demonstrated that an exceptional event caused a specific air pollution 

concentration in excess of one or more NAAOS at a pa11icular air quality 

monitoring location. and the Agency otherwise satisfies the requirements 

of 40 CFR 50.14. 

2) Fireworks Displays. USEPA has stated that it will exclude data from use 

in dete1minations of exceedance of an NAAOS where the Agency has 

demonstrated that emissions from fireworks displays caused a specific air 

pollution concentration in excess of one or more NAAOS at a par1icular 

air quality monitoring location. and the State othe1wise satisfies the 

requirements of 40 CFR 50.14. USEPA has stated that these data will be 

treated in the same manner as exceptional events under this Section. 

provided the Agency has demonstrated that the use of fireworks is 

significantly integral to traditional national. etlmic. or other cultural 

events. including. but not limited to July Fourth celebrations. which satisfy 

the requirements of 40 CFR 50.14. 

3) Prescribed Fires. USEPA has stated that it will exclude data from use in 

dete1minations of exceedance of an NAAOS where the Agency has 

demonstrated that emissions from prescribed fires caused a specific air 

pollution concentration in excess of one or more NAAOS at a pa1iicular 

air quality monitming location. and the Agency othe1wise satisfies the 

requirements of 40 CFR 50.14. provided that the emissions are from 

prescribed fires that USEP A dete1mines meets the definition of 

"exceptional event" iri Section 243.101. and provided that the Agency has 

ce1iified to USEPA that the State has adopted and is implementing a 

Smoke Management Program (SMP) or the State has ensured that the 

bumer employed basic smoke management practices. If an exceptional 

event occurs using the basic smoke management practices approach. the 

Agencv must unde1iake a review of the State's approach to ensure public 

health is being protected and must include consideration of development 

of an SMP. 

BOARD NOTE: In each ofconesponding 40 CFR 50.14(b)(l). (b)(2). and (b)(3). 

USEP A stated "EPA shall exclude data from use in detenninations of 

exceedances and NAAOS violations." In the first person. "shall" is used more to 

express present intent or to commit to future action. The Board has changed 
"EPA shall" to "USEP A has stated that it will." Further. the Board has relied on 

the defined term "exceedance of an NAAQS." 

c) Schedules and Procedures. 

I) Public notification. The Agency or. where the Agency has delegated 

authority pursuant to Section 4(g) or (r) of the Act. the Agency's 

delegatee. must notify the public promptly whenever an event occurs or is 

reasonably anticipated to occur that may result in the exceedance of an 

NAAQS. 

2) Flagging of Data. 

A) The Agency must notify USEPA of the State's intent to exclude 

one or more measured exceedances of an NAAQS as being due to 

an exceptional event by placing a flag in the appropriate field for 

the data record of concern that has been submitted to the federal air 

quality system (AQS) database. 

B) Flags placed on data in accordance with this Section must be 

deemed inf01mational only. and the data must not be excluded 

from detetminations with respect to an exceedance of an NAAQS 

unless and until USEPA notifies the Agency of US EPA 

concmTence following the Agency's submittal of a demonstration 

pursuant to subsection (c)(3) ofthis Section by placing a 

concmTence flag in the appropriate field for the data record in the 

AQS database. 

C) Flags placed on data as being due to an exceptional event. together 

with an initial description of the event. must be submitted to 

USEP A not later than July 1 of the calendar year following the 

year in which the flagged measurement occurred. except as 

allowed under subsection (c)(2)(D) or (c)(2)(E) of this Section. 

D) This subsection (c)(2)(D) con·esponds with 40 CFR 

50.14(c)(2)(iv). which has expired by its own tenns. This 

statement maintains structural consistency with the federal 

regulations. 

E) This subsection (c)(2)(E) corresponds with 40 CFR 50.14(c)(2)(v). 

which has expired by its own tetms. This statement maintains 

stmctural consistency with the federal regulations. 

F) USEPA has stated that when USEPA sets a NAAOS for a new 

pollutant or revises the NAAQS for an existing pollutant. USEPA 

may revise or set a new schedule for flagging exceptional event 
data. providing initial data descliptions. and providing detailed 

data documentation in AQS for the initial designations of areas for 

those NAAQS. Table A for this Pmt provides the existing 

schedule for submission of flags with initial descriptions in AQS 

and detailed documentation. These schedules apply for those data 

that will or may influence the initial designation of areas for those 

NAAQS. USEPA has stated that it will revise the table upon 

which Table A is based as necessmy to accommodate revised data 

submission schedules for new or revised NAAQS. 

3) Submission of demonstrations. 

A) When the Agency has flagged data as being due to an exceptional 

event and is requesting exclusion of the affected measurement 

data. the Agency must after notice and opportunity for public 

comment submit a demonstration to USEP A to justify data 

exclusion· not later than the sooner of three years following the end 

of the calendar qumter in which the flagged concentration was 

recorded or 12 months prior to the date that a regulatmy decision 

must be made by USEP A. The Agency must submit to USEPA the 

public comments it received. along with its demonstration. 

B) This subsection (c)(3)(B) conesponds with 40 CFR 50.!4(b)(3)(ii). 

which pertains only to a repmting period and opportunity to 

demonstrate exceptions that has passed. This statement maintains 

structural consistency with the federal regulations. 

C) This subsection (c)(3)(B) conesponds with 40 CFR 50.14(b)(3)(ii), 

which pertains only to a reporting period and oppmtunity to 

demonstrate exceptional events that has passed in a provision that 

has expired by its own terms. This statement maintains stmctural 

consistency with the federal regulations. 

D) The demonstration to justify data exclusion must provide the 

following evidence: 

i) That the event satisfies the definition of"exceptional 

event" set fmth in Section 243.101: 

ii) That there is a clear causal relationship between the 

measurement under consideration and the event that is 

claimed to have affected the air quality in the m·ea; 

iii) That the event is associated with a measured concentration 

in excess of nmmal historical fluctuations. including 

background; and 
iv) That there would have been no exceedance or violation but 

for the event. 

E) With the submission of the demonstration. the Agency must 

document that the public comment process was followed. 

BOARD NOTE: Derived from 40 CFR 50.14 (2012). 

(Source: Added at 37 Ill. Reg. ___ , effective----------' 

Section 243.106 Monitoring (Repealed) 

Pelltltien levels 'Nil! ae EletermineEI B)' fiJceEI 81" meaile samj3ling stffiiens aeyenEI tae j3Femises SR 

v:aieh a seuree is leeateEI. Statiens will ae leeateEI aeeerEiing te the guilEielines feF estaalisaeEI 

menite1ing netv:erks as Ele•;elej3eEI ay the UniteEI States EnYiwrunefltal Preteetien Agene:y. 

(Source: Repealed at 37 Ill. Reg. ____ , effective----------' 

Section 243.107 Reference Conditions 

All measurements of air quality that are expressed as mass per unit volume (e.g .. micrograms per 

cubic meter, eJ<eej3t other than for particulate matter (PM25) standards contained in Section 

243.120(b) and (c) and lead standards contained in Section 243.126(b), are corrected to a 

reference temperature of25°_C, and to a reference pressure of760 millimeters ofmercmy 

(I 013.2 millibars). Measurements of PM2.5, for pmposes of comparison to the standards 

contained in Section 243.120(b) and (c), and lead, measure!Bents saall for purposes of 

compa1ison to the standards contained in Section 243 .126(b ). must be reported based upon the 

actual ambient air volume measured at the actual temperature and pressure at the monitoring site 

during the measurement period. 

BOARD NOTE: Derived from40 CFR 50.3 (2012). 

(Source: Amended at 3 7 Ill. Reg. ____ , effective----------' 

Section 243.108 Incorporations by Reference 

The following materials are inc01porated by reference. These inc01porations do not include any 

later amendments or editions: 

a) Pararesaniline metaeEI, 40 CPR 50, a!l!leneiK A (19&2). 

a) l'len Elisj3ersive infraFeEI Sfleetremelfy teehniEflle, 4 0 CPR 50, aj3j3eREiiJl c (19&2), 

36 PeEl. Reg. 22391, NevemaeF 25, 1971. 

e) Celerimelfie metheEI, 36 PeEl. Reg. 22396, Nevenwer 25, 1971. 
El) OzeHe efk:,·leHe reaetieH metkeE!, 1Q CFR §Q, E!JlJ3eHElix D (1981), 36 FeEl. Reg. 

22392, J>!eveH1aer 2§, 1971. 

e) LeaE!, 4Q CFR §Q, E!JlJ3eHElix G (1QQ8). 

f) Refereaee metl1eE! fer tl1e Eletefl11iHatieH efj'lartiealate matter as PM-w..ifl-.tke 

atmesJ3l1ere, 4Q CFR §Q, E!JlJ3eHElil< J (199Q). 

g) illterJ3retatieH eftae J>!atieHal AmaieHt Air Qaality StaHElarE!s (NAAQS) fer 

J3artiealate 111atter, 4 Q CFR §Q, E!JlJ3eHE!iJ< K, 73 FeEl. Reg. 6114 4 (Oeteaer 17, 

~ 

l1) Refereaee 111etl1eE! fer tl1e EletermiaatieH efj3artiealate matter as l'Mg..ifl-.tke 

atmesJ3here, 4Q CFR §Q, E!JlJ3eHEliK L, 73 FeEl. Reg. 61144 (Oeteaer 17, 2QQ6). 

i) illterJ3retatieH eftke J>!JV.QS fer I'}.<!;,.,;;, 1Q CFR SQ, aJ3J3eHElix J>!, 73 FeEl. Reg. 

1497 (Jaooary 9, 2QQ8). 

j) illteFJ3retatieH eftl1e J>!AAQS fer 0~, 4Q CFR §Q, aJ3J3eHElill P, 73 FeEl. Reg. 16436 

(Mweh 27, 2QQ8). 

k) The HAAQS fer LeaE!; FiHal Rale, 4Q CFR SQ, §I, §3, aHa §8, 73 FeEl. Reg. 

66964 (J>!evemaer 12, 2QQ8). 

I) illterJ3retatieH eftl1e J>!AAQS fer LeaE!, 4Q CFR §Q, aJ3J3eaEliK R, 73 FeEl. Reg. 

66964 (NeveHwer 11, 2QQ8). 

Government Printing Office (GPO). 732 Capitol Street NW. Washington. DC 

20401 (telephone: 202-512-1800 or 866-512-1800: website: www.gpo.gov). 

The following documents incmporated by reference are available from this 

source: 

Appendix A-1 to 40 CFR 50 (2012) (Reference Measurement Principle 

and Calibration Procedure for the Measurement of Sulfur Dioxide in the 

Atmosphere (Ultraviolet Fluorescence Method)). referenced in Section 

243.122. 

Appendix A-2 to 40 CFR 50 (2012) (Reference Method for the 

Detetmination of Sulfur Dioxide in the Atmosphere (Pararosaniline 

Method)). referenced in Section 243.122. 

Appendix B to 40 CFR 50 (2012) (Reference Method for the 

Determination of Suspended Particulate Matter in the Atmosphere (HighVolume Method)). referenced in appendix G to 40 CFR 50 (see below). 
Appendix C to 40 CFR 50 (2012) (Reference Measurement Principle and 

Calibration Procedure for the Measurement of Carbon Monoxide in the 

Atmosphere (Non-Dispersive Infrared Photometry)), referenced in Section 

243,]23. 

Appendix D to 40 CFR 50 (2012) (Reference Measurement Principle and 

Calibration Procedure for the Measurement of Ozone in the Atmosphere), 

referenced in Section 243,]25. 

Appendix F to 40 CFR 50 (2012) (Reference Measurement P1inciple and 

Calibration Procedure for the Measurement of Nitrogen Dioxide in the 

Atmosphere (Gas Phase Chemiluminescence)). referenced in Section 

243,]24. 

Appendix G to 40 CFR 50 (2012) (Reference Method for the 

Dete1mination of Lead in Suspended Particulate Matter Collected from 

Ambient Air). referenced in Section 243.126. 

Appendix H to 40 CFR 50 (2012) (Interpretation of the !-Hour Primary 

and Secondary National Ambient Air Quality Standards for Ozone). 

referenced in Section 243.175. 

Appendix I to 40 CFR 50 (2012) (Interpretation of the 8-Hour Primary and 

Secondmy National Ambient Air Quality Standards for Ozone), 

referenced in Section 243.125. 

Appendix J to 40 CFR 50 (2012) (Reference Method for the 

Detem1ination of Particulate Matter as PM10 in the Atmosphere. 

referenced in Section 243,]20. 

Appendix K to 40 CFR 50 (2012) (Interpretation of the Primary and 

Secondmy National Ambient Air Quality Standards for Particulate 

Matter). referenced in Section 243.120. 

Appendix L to 40 CFR 50 (2012) (Reference Method for the 

Determination of Fine Pmticulate Matter as PM?.S in the Atmosphere), 

referenced in Section 243.120. 

Appendix N to 40 CFR 50 (2012) (Interpretation of the Prin1m·y and 

Secondmy National Ambient Air Qualitv Standards for Pmticulate 

Matter), referenced in Section 243.120. 

Appendix 0 to 40 CFR 50 (20 12) (Reference Method for the 

Determination of Coarse Particulate Matter as PM10•25 in the 

Atmosphere), referenced in appendix Q to 40 CFR 50 and for use in 
federally required monitoring by the NCore system pursuant to 40 CFR 

~ 

Appendix P to 40 CFR 50 (2012) (Intetpretation of the Primary and 

Secondaty National Ambient Aii· Quality Standards for Ozone). 

referenced in Section 243.125. 

Appendix Q to 40 CFR 50 (201 2) (Reference Method for the 

Determination of Lead in Pmiiculate Matter as PMIO Collected from 

Ambient Air). referenced in appendix R to 40 CFR 50. 

Appendix R to 40 CFR 50 (2012) (Intemretation of the National Ambient 

Air Quality Standards for Lead). referenced in Section 243.126. 

Appendix S to 40 CFR 50 (2012) (Intemretation of the Primary National 

Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen 

Dioxide)). referenced in Section 243.124. 

Appendix T to 40 CFR 50 (2012) (Intemretation of the Primary National 

Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide)). 

referenced in Section 243.122. 

Clean Air Act. 42 USC 7401 et seq. (201 I) (for definitions oftetms onlv). 

referenced in Section 243.102. 

BOARD NOTE: Segments of the Code of Federal Regulations and the 

United States Code are available for free download as PDF documents 

from the GPO FDsys website: http://www.gpo.gov/fdsys/. 

USEP A. National Exposure Research Laboratmy. Human Exposure & 

Atmospheric Sciences Division (MD-D205-03l. Research Triangle Park. NC 

2771 I. The following documents incomorated by reference are available from 

this source: 

"List of Designated Reference and Equivalent Methods" (December I 7. 

20 12) (refetTed to as "List of Designated Methods" and referenced in 

Sections 243.IOL 243.120.243.122.243.123.243.124.243.125. and 

243.126. 

This reference includes the no Federal Register notices subsequent to 

December 17.2012 that updated List of Designated Methods. 

BOARD NOTE: This document is available for free download as a PDF 

document from the USEP A. Technology Transfer. Ambient Monitoring 

Technology Infmmation Center website: http://www.epa.gov/ttn/amtic/ 

criteria.html. 
(Source: Amended at 37 Ill. Reg. ____ ., effective _________ __, 

SUBPART B: STANDARDS AND MEASUREMENT METHODS 

Section 243.120 PM10 and PM2.5 

a) Staflelanls. The primary aael seeeflelary aiflllieflt air EfHality staflelaffis fer PMw.are 

a maKitfiHm 24 hem average eeHeefltratisfl sf 150 fl§'m". The staaelarels m·e 

attaifleel whea the expeeteel oomller ef elays per ealefldar year ·.vith a 2 4 hsHr 

EP<erage 68fl6efltratiefl aee;·e 150 j±g,lrn~ is eEfHal te SF less than Sfle, as fl1eaSHreeJ 

aBel eletermmeel ifl aeeerelaflee with sHIJseetiefl (ll). 

ll) MeasHrefl1eflt Methed. Fer eletermmiflg eeHfermaflee v:ith the PM,1l-ameieflt air 

Eft!ality staaelarels, PMw shall he measHreellly the metheel eleserilleel ifl 40 CFR 50, 

appeaeliJE J er aa eEft!ivaleflt methed elesigflateel flHrSHaflt te 4 0 CFR 53 

(ineefj'lerateellly refereflee ifl Seetiefl243.108). The staflelarels are attaifleel whefl 

the eJEj3eeted oomller efela:,·s per ealeflelar year with a 24 heHr average 

eefleefltratiea all eve 150 j±g.'m~ is eEfHal ts sr less thafl Sfle, as eletermifleel ifl 

aeesrelaaee with 40 CFR 50, appeHelix K (ifiGSf]'lsrateel ey refereflee ifl Seetisfl 

243.108). 

e) Staflelarels. The pri111ary aael seesflelary amllient air Eft!ality staflelarels fer P~.4;,.,; 

tli'<* 

I) An ffi1ffiial arithmetie mean esHeefltratiefl ef 15.0 j±glm" aBel as measHreel 

aael eletermmed ifl eeHfermaflee ·.vith st~eseetiefl (el). 

2) A maKimHm 24 hem eefleefltratiefl ef35 j±§'m~. at tee 98th flereefltile 

valHe, aBel as measHred aBel datemnfleel ifl eeafermaaee ·.vita sHeseetiefl 

fdr. 

el) Meast~remeflt Metheel fer P~4;,.,;. Fer eletermiiliflg eeflfermaflee ·.vita the P~.4;,.,; 

amllieflt air EfHality staflelarels, P~.4;,.,; shall he measHred lly tee metheel eleserilleel ifl 

4 0 CFR 50, aflpefleliJE L er afl eEfHivaleflt metheel elesigaateel pt~rst~aflt te 4 0 CFR 

53 (meerperated lly refereflee ifl Seetiefl243.108). Cell1]3liaflee ·.vith tee 

staflelarels is eletermifled Hsiflg tee metheds aBel preeeelt~res eleserilleel ill 40 CFR 

50, appeHEliJE 1'1 (ifleefj'lerateellly refereflee ifl Seetiefl243.108). 

I) The aflfltlal fllimffi')' aBel seeeflelary P~4;,.,; stafldarels are met v:hefl the 

aflfltlal arithmetie meafl eefleefltratiefl, as eletetmmeel ifl aeeerelaflee with 

40 CFR 50, appeHeliJE 1'1, is less taafl er eEfHal te 15.0 j±g/m~" 

2) The 24 hem prllilary aBel seeeflelaiy P~.4;,.,; staflelarels are met whefl the 

98th pereefltile 24 heHr eefleeflt1·atiefl, as eletermifleel ifl aeeerdaflee wita 

40 CFR 50, appefleliJE N, is less taafl er eEfHal te 35 !±§'m~" 
a) 1987 Primary and Secondary 24-Hour NAAOS for PM10• 

I) The level of the 1987 primary and secondary 24-hour NAAOS for PM10 is 

150 l!glm3

• 24-hour average concentration. The 1987 primary and 

secondary NAAOS for PM10 is attained when the expected number of 

days per calendar year with a 24-hour average concentration above 150 

u,g/m3

• as determined in accordance with appendix K to 40 CFR 50. 

incorporated by reference in Section 243.108. is equal to or less than one. 

2) This subsection (a)(2) conesponds with 40 CFR 51.6(b). a provision 

marked "reserved" by USEP A. This statement maintains structural 

consistency with the conesponding federal regulation. 

3) For the purpose of detennining attainment of the 1987 primary and 

secondary 24-hour NAAOS for PM10• particulate matter must be measured 

in the ambient air as PM10 by a method that fulfills either of the following 

requirements: 

A) An FRM based on appendix J to 40 CFR 50. incomorated 

by reference in Section 243.108. and designated by USEPA 

and listed in List of Designated Methods. incmporated by 

reference in Section 243.108: or 

Bl An FEM designated by USEPA and listed in List of Designated 

Methods. incmporated by reference in Section 243.108. 

BOARD NOTE: This subsection (a) is derived from 40 CFR 50.6 

(2012). USEPA adopted 1997 primatyNAAOS for PM10 at 62 Fed. Reg. 38652 

(July 18. 1997). As a result of a judicial vacatur. USEPA later removed the 

transitional provision relative to the 1987 NAAOS at 65 Fed. Reg. 80776 (Dec. 

22. 2000) and the 1997 NAAOS at 69 Fed. Reg. 45595 (July 30. 2004). Thus. the 

1987 primary and secondary NAAOS for PM10 are included in this subsection (a). 

b) 1997 Primary and Secondary Annual Average and 24 HourNAAOS for PM, 5 . 

1) The 1997 primary and secondary annual average NAAOS for PM,_5 is 

15.0 l!glm3

• annual aritlnnetic mean concentration. and the 1997 primar·y 

and secondary 24-hour NAAOS for PM, 5 is 65 u.g/m3

• 24-hour average 

concentration. measured in the ambient air as PM,_5 by a method that 

fulfills either of the following requirements: 

A) An FRM based on appendix L of 40 CFR 50. incmporated by 

reference in Section 243.108. and designated by USEPA and listed 

in the List of Designated Methods. incorporated by reference in 

Section 243.108: or 
B) An FEM designated by USEPA and listed in the List of Designated 

Methods. incmporated by reference in Section 243.108. 

2) The 1997 primary and secondary annual average NAAQS for PM,_5 is met 

when the annual arithmetic mean concentration. as dete1mined in 

accordance with appendix N of 40 CFR 50. incomorated by reference in 

Section 243.108. is less than or equal to 15.0 ug/m3 

3) The 1997 primary and secondary 24-hour NAAQS for PM, 5 is met when 

the 98th percentile 24-hour concentration. as detennined in accordance 

with appendix N of 40 CFR 50. incmporated by reference in Section 

243.108. is less than or equal to 65 ug/m3

. 

BOARD NOTE: This subsection (b) is derived from 40 CFR 50.7 (2012). The 

2006 primary and secondary annual average and 24-hour NAAQS for PM , 5 

differs from the 1997 standards in that the 24-hour average concentration required 

by the 2006 standard is substantially lower (more stringent) than that for the 1997 

standard. The Board has retained the 1997 standard in this subsection (b) because 

USEPA has retained the 1997 standard in 40 CFR 50.6. 

c) 2006 Primary and Secondary Annual Average and 24-Hour NAAQS for PM, 5. 

1) The 2006 primary and secondmy annual average NAAOS for PM,_5 is 

15.0 [Lg/m3

• annualm·ithmetic mean concentration. and the 2006 primary 

and secondary 24-hour NAAQS for PM,_5 is 35 ug/m3

• 24-hour average 

concentration. measured in the ambient air as PM,_5 by a method that 

fulfills either of the following requirements: 

A) An FRM based on appendix L of 40 CFR 50. incmporated by 

reference in Section 243.108. and designated by USEPA and listed 

in the List of Designated Methods. incmporated by reference in 

Section 243.108: or 

B) An FEM designated by USEPA and listed in the List of Designated 

Methods. incomorated by reference in Section 243.108. 

2) The 2006 primary and secondary annual average NAAQS for PM, 5 is met 

when the annual arithmetic mean concentration. as dete1mined in 

accordance with appendix N of 40 CFR 50. incomorated by reference in 

Section 243.108. is less than or equal to 15.0 ug/m3 

3) The 2006 primary and secondary 24-hour NAAQS for PM, 5 is met when 

the 98th percentile 24-hour concentration. as dete1mined in accordance 

with appendix N of 40 CFR 50. incomorated by reference in Section 

243.108. is less than or equal to 3 5 ug/m3 
BOARD NOTE: This subsection (c) is derived from 40 CFR 50.13 (2012). 

(Source: Amended at 37 Ill. Reg. ___ ., effective _________ _, 

Section 243.122 Sulfur Oxides (Sulfur Dioxide) 

a) Primary StaaEiarEis. The J3rHTtary aa1biem air EjUality staaEiares fer sulfur eKiaes 

meastrred as sHlfHr HieJ:.iEle are: 

l) An a1111Ual aritbmeti6 meaa 6SB6effiratiea sf go fig.'m;; (0.03 J3J3m); aae, 

2) A maKimum 24 fieur 68Beeatratiea, 11et te be eK6eeeee mere tfian e116e 

J3er year, ef365 fi§l.m;; (0.14 J3J3m). 

b) Se6eaeary Staaeare. The se6e11dary ambieffi air EjUality standard fer sulfur eKides 

measured as sulfur dieJdee is a BlallHTtum 3 fieur 68B6eatratie11 aet te be eJ<6eedeEl 

mere tfia11 8116e J3er year sf 1,300 fig.l.m;; (0.5 J3J3m). 

e) Measureme11t MetfieEl. fer detern1iaiag eellfem1aB6e witfi sulfur eKide air EjUality 

staadards, sulfur m<iees sfiall be measured as sulful· dieKide by tfie J3araresanili11e 

111etfied des6ribed i11 40 CFR 50, aJ3J3eBdiK A, (iB6SFJ3srateEI by: refere116e i11 

Se6tie11 243.!0g), er by an BEjUh'aleat metfied efJ3reSfaj'lJ3FSVed by tfie Agea6y. 

a) 1971 Primary Annual Average and 24-Hour NAAOS for Sulfur Oxides (as Sulfur 

Dioxide (SO,)). 

1) The level of the 1971 primmy annual average NAAOS for sulfur oxides is 

0.030 ppm. not to be exceeded in a calendar year. The annual arithmetic 

mean must be rounded to three decimal places (fractional parts equal to or 

greater than 0.0005 ppm must be rounded up). 

2) The level of the 1971 primmy 24-hour NAAOS for sulfur oxides is 0.14 

ppm. not to be exceeded more than once per calendar year. The 24-hour 

averages must be detetmined from successive non-overlapping 24-hour 

blocks starting at midnight each calendar day and must be rounded to two 

decimal places (fractional parts equal to or greater than 0.005 ppm must be 

rounded up). 

3) Sulfur oxides must be measured in the ambient air as SO, by the FRM 

described in appendix A-2 to 40 CFR 50. incorporated by reference in 

Section 243.108. or by an FEM designated by US EPA and listed in the 

List of Designated Methods. incorporated by reference in Section 243.108. 

4) To demonstrate attainment. the annual arithmetic mean and the secondhighest 24-hour averages must be based upon hourly data that are at least 

7 5 percent complete in each calendar quarter. A 24-hour block average 
must be considered valid if at least 75 percent of the hourly averages for 

the 24-hour pe1iod are available. In the event that only 18-, 19-,20-,21-. 

22-, or 23-hour averages are available, the 24-hour block average must be 

computed as the sum of the available hourly averages using the number of 

hours (i.e .. 18, 19, etc.) as the divisor. Ifless than 18-hour averages are 

available, but the 24-hour average would exceed the level of the standard 

when zeros are substituted for the missing values, subject to the rounding 

rule of subsection (b) of this Section, this must be considered a valid 24-

hour average. In this case, the 24-hour block average must be computed 

as the sum of the available hourly averages divided by 24. 

5) The 1971 P'imary annual average and 24-hour NAAOS for sulfur oxides 

set forth in this subsection (a) remains applicable to all areas 

notwithstanding the promulgation of the 2010 primmy one-hour NAAOS 

for sulfur oxides in subsection (c) of this Section. The Board will delete 

the 1971 primary annual average and 24-hour NAAOS for sulfur oxides 

set forth in this subsection (a) after fulfilhnent of the conditions recited by 

USEPA in conesponding 40 CFR 50.4(e). 

BOARD NOTE: Conesponding 40 CFR 50.4(e) recites that the 1971 

primary NAAOS for sulfur oxides remains effective in two tvpes of areas 

for which USEP A has not yet approved an implementation plan for 

attainment with the 2010 primary one-hour NAAOS for sulfur oxides. 

The first type of area is one that USEP A had designated as non-attainment 

for that standard as of the effective date of the 20 10 primary one-hour 

NAAOS for the 1971 primmy NAAOS for sulfur oxides as of the effective 

date of the 2010 NAAOS. That date was August 23,2010. See 75 Fed. 

Reg. 35520 (June 22. 2010). As of that date, USEPA had not designated 

any area in Illinois as non-attainment. See 40 CFR 81.314 (201 0). The 

Board is unaware of any US EPA SIP call for any area of Illinois relative 

to the 1971 primary NAAOS for sulfur oxides. As of December 31, 2012, 

USEP A had not vet designated the attainment status of areas in Illinois. 

See 40 CFR 81.314 (2012). The Agency recommended that USEPA 

designate limited areas of Illinois as non-attainment with the 20 I 0 primary 

one-hour NAAOS. See letter of June 2. 2011 from Laurel Kroack. Chief. 

Bureau of Air. Agency, to Che1yl A. Newton, Director, Office of the Air 

and Radiation Division, USEP A Region 5 (available at 

http://www.epa.gov/so2designations/recletters/ 

R5 IL rec wtechanalysis.pdf). When the conditions of this subsection 

(a)(5) have been fulfilled, or USEP A has removed 40 CFR 50.4, the Board 

will remove the standard of this subsection (a) as obsolete. 

BOARD NOTE: This subsection (a) is derived from 40 CFR 50.4 (2012). 

b) 1971 Secondary Three-Hour NAAOS for Sulfur Oxides (as S02). 
I) The level ofthe 1971 secondarythree-hourNAAOS for sulfur oxides is 

0.5 ppm. not to be exceeded more than once per calendar year. The threehour averages must be determined from successive non-overlapping threehour blocks sta1ting at midnight each calendar day and must be rounded to 

one decimal place (fractional pmis equal to or greater than 0.05 ppm must 

be rounded up). 

2) Sulfur oxides must be measured in the ambient air as SO, by the FRM 

described in appendix A-2 to 40 CFR 50. incorporated by reference in 

Section 243.108. or by an FEM designated by US EPA and listed in List of 

Designated Methods. incorporated by reference in Section 243.108. 

3) To demonstrate attainment. the second-highest tlu·ee-hour average must be 

based upon hourly data that are at least 75 percent complete in each 

calendar qumier. A three-hour block average must be considered valid 

only if all three hourly averages for the three-hour period are available. If 

only one or two hourly averages are available. but the tlu·ee-hour average 

would exceed the level of the standard when zeros are substituted for the 

missing values. subject to the rounding mle of subsection (b )(I) of this 

Section. this must be considered a valid three-hour average. In all cases. 

the three-hour block average must be computed as the sum of the hourly 

averages divided by tlu·ee. 

BOARD NOTE: This subsection (b) is derived from 40 CFR 50.5 (2012). 

c) ?OJO Primary One-Hour NAAOS for Sulfur Oxides (as SO;,l 

I) The level of the 2010 primmy one-hour NAAOS for sulfur oxides is 75 

ppb. measured in the ambient air as SO,. 

2) The 2010 one-hour primary NAAOS for sulfur oxides is met at an ambient 

air quality monitming site when the tlu·ee-year average of the annual (99th 

percentile) of the daily maximum one-hour average concentrations is less 

than or equal to 75 ppb. as detennined in accordance with appendix T of 

40 CFR 50. incorporated by reference in Section 243.108. 

3) The level of the 2010 one-hour primary NAAOS for sulfur oxides must be 

measured by an FRM based on appendix A-1 or A-2 of 40 CFR 50. 

incorporated by reference in Section 243.108. or by an FEM designated by 

USEP A and listed in List of Designated Methods. incorporated by 

reference in Section 243.108. 

BOARD NOTE: This subsection (c) is derived from 40 CFR 50.17 (2012). The 

1971 primary NAAOS for SO, remains in effect until the federal conditions of 40 

CFR 50.4(e) have been fulfilled. as outlined in subsection (a)(5) of this Section 

and the appended Board note. 
(Source: Amended at 37 Ill. Reg. ____ , effective _________ __} 

Section 243.123 Carbon Monoxide 

a) StaaEiarEis. The amhieHt air EJHality staaEiarEis fur earhea meaeKiEie are: 

1) A mm<imHm g heer eoaeeatratioa aot to he eJ<eeeEieEI more thaa oaee IJer 

year of 10 milligrams IJer et!hie meter (9 flflll'l); aaEI, 

2) A B1aJEiffi:Hn1 1 heHr eeaeeatfatiea aet te Se eKeeeEleEl more thaa oaee fJSr 

year of 40 milligrams IJer eehie meter (35 IJIJm). 

h) MeaserealeHt MethoEI. For EletermiHiag eoafurmaaee with the earhoa moaoJ<iEie 

air Ejt!ality staaEiarEI, earhoa moaoKiEie shall he measereEI hy the aoaEiisiJ8ffii..¥e 

inii·areEI SIJeetrometry teehHiEjt!e as EleseriheEI iR 40 CFR 50, AJ3J3. C (1982), 3a 

FeEl. Reg. 22,391, l'!O':emller 25, 1971, or lly aa eEJeP.·aleHt HlethoEI SfliJroveEiey 

the Ageaey. 

a) The 1971 eight-hour and one-hour primary NAAQS for carbon monoxide are as 

follows: 

I) An eight-hour average concentration of 9 ppm (I 0 mg/m\ not to be 

exceeded more than once per year: and 

2) A one-hour average concentration of 35 ppm ( 40 mg/m\ not to be 

exceeded more than once per year. 

b) The levels of carbon monoxide in the ambient air must be measured bv a method 

that fulfills either of the following requirements: 

I) An FRM based on appendix C of 40 CFR 50. incmporated by reference in 

Section 243.108. and designated by USEPA and listed in the List of 

Designated Methods. incmporated by reference in Section 243.108: or 

2) An FEM designated by USEPA and listed in the List of Designated 

Methods. incmporated by reference in Section 243.108. 

c) An eight-hour average concentration must be considered valid if at least 75 

percent of the hourly average for the eight-hour period is available. In the event 

that only six-hour (or seven-hour) averages are available. the eight-hour average 

must be computed on the basis of the hours available using six (or seven) as the 

divisor. 

d) When summarizing data for comparison with the standards. averages must be 

stated to one decimal place. Comparison of the data with the levels of the 
standards in ppm must be made in te1ms of integers with fractional parts of 0.5 or 

greater rounded up. 

BOARD NOTE: This Section is de1ived from 40 CFR 50.8 (?012). 

(Source: Amended at 37 Ill. Reg. ____ , effective _________ _} 

Section 243.124 Nitrogen Oxides (Nitrogen Dioxide as Indicator) 

a) StaaEianl. The affil3ieat air Ef!ialit)' stffi!EiarEI fer ffitregea ElimtiEie is aR a!lffilal 

arithtnetie meaa eeaeeatratiea ef 100 mieregrams 13er et4ie meter (0.0§ !l!l!H). 

13) Measureraeat MetlleEI. F'er Elete!Tniffiag eeafennaaee with tlle aitre gea ElimtiEie 

air Ef!ialit)' staaEiarEI, aitregea ElieJtiEie shalllle a1easureEilly tlle eelerimetrie 

metlleEI as EleserilleEI ia 36 feEl. Reg. 22,396, }!eveffil3er 2§, 1971, er lly aa 

eEjuivaleat metheEI ~!lreveEill)' the Ageaey. 

a) The level of the 1971 primary annual average NAAOS for nitrogen oxides is 53 

ppb. annual average concentration. measured in the ambient air as nitrogen 

dioxide (NO,). 

b) The level of the 2010 primmy one-hour NAAOS for nitrogen oxides is 100 ppb. 

one-hour average concentration. measured in the ambient air as NO,. 

c) The level of the 1971 secondary annual average NAAOS for nitrogen oxides is 

0.053 ppm (I 00 uglm\ annual m·ithmetic mean concentration. measured in the 

mnbient air as NO,~ 

dl The levels of the standards in subsections (a) tlu·ough (c) of this Section must be 

measured by: 

I) An FRM based on appendix F to 40 CFR 50. incmporated by reference in 

Section 243.108. and designated by USEP A and listed in the List of 

Designated Methods. incmporated by reference in Section 243.108: or 

2) By an FEM designated by USEP A and listed in the List of Designated 

Methods. incmporated by reference in Section 243.108. 

e) The 1971 primary annual average NAAQS for nitrogen oxides in subsection (a) of 

this Section is met when the annual average concentration in a calendar year is 

less than or equal to 53 ppb. as dete1mined in accordance with appendix S of 40 

CFR 50. incmporated by reference in Section 243.108. for the annual standard. 

f) The 2010 one-hour primary NAAOS for nitrogen oxides in subsection (b) of this 

Section is met when the tlu·ee-year average of the annual 98th percentile of the 

daily maximum one-hour average concentration is less than or equal to 100 ppb. 
as determined in accordance with appendix S of 40 CFR 50, incorporated by 

reference in Section 243.108, for the !-hour standard. 

g) The 1971 secondary annual average NAAQS for nitrogen oxides in subsection (c) 

of this Section is attained when the annual arithmetic mean concentration in a 

calendar year is less than or equal to 0.053 ppm, rounded to tlu·ee decimal places 

(fractional parts equal to or greater than 0.0005 ppm must be rounded up). To 

demonstrate attaimnent an annual mean must be based upon hourly data that are 

at least 75 percent complete or upon data derived from manual methods that are at 

least 75 percent complete for the scheduled sampling days in each calendar 

qumter. 

BOARD NOTE: This Section is derived from 40 CFR 50.11 (2012). 

(Source: Amended at 3 7 Ill. Reg. ____ , effective-----------' 

Section 243.125 8 IItniF Ozone 

a) Staaaanl The p1iraary aaa seeeaaary anillieat air EJ:Uality staaaaras fer ezeae are 

Q.Q73 ppra (!larts per railliea) aaily raaJtiffiaa1 8 aeHr !l'<'erage eeaeeatratiea, 

measHrea aaa aete1miaea ia aeeeraaaee witll. slill.seetiea (13). 

e) MeasmeH!eat Metll.ea. Ozeae saall ee measHrea ey a federal efiHiYaleat methea 

easea ea 4Q CFR 3Q, appeaaiK D aaa aesigaatea ia aeem·aaaee ·.vita 4Q CFR 33 

(iaeerperatea B)' refureaee ia Seetiea 243 .I Q8) er aa eEJ:Uivaleat raetll.ea 

aesigaatea ia aeeeraaaee ·.vita 4 Q CFR 33. The prialary aaa seeeaaary ameieat 

air EJ:Uality staaaaras are raet waea tae a':erage ef !Be aaaHal feHrta highest aaily 

raaJtia1tlra 8 heHr average ezeae eeaeeatratiea is less taaa er eEJ:Ual te Q.Q73 ppm, 

as aetelmiaea HSiag 4Q CFR 3Q, appeaailt p (iaeerperatea ey refureaee ia Seetiea 

243.1Q8). 

a) 1997 Primarv and Secondary Eight-Hour NAAQS for Ozone. 

I) The 1997 hour primary and secondary eight-hour NAAQS for ozone, 

measured by an FRM based on appendix D to 40 CFR 50, incorporated by 

reference in Section 243.108. and designated by USEPA and listed in the 

List of Designated Methods, incorporated by reference in Section 243.108, 

is 0.08 ppm. daily maximum eight-hour average. 

2) The 1997 primary and secondary eight-hour NAAQS for ozone is met at 

an ambient air quality monitoring site when the average of the annual 

fomth-highest daily maximum eight-hour average ozone concentt·ation is 

less than or equal to 0.08 ppm, as detetmined in accordance with appendix 

I to 40 CFR 50, incorporated by reference in Section 243.108. 
Fed. Reg. 66964 (Nov. 12. 2008). USEPA designated Granite City as 

nonattainment with the 2008 primary and secondary three-month average 

NAAQS for lead in 2010 and an area of Chicago in 2011. USEPA 

designated all other areas of Illinois for the 2008 primmy and secondary 

three-month average NAAQS for lead in 2012. See 40 CFR 81.314 (area 

designations in Illinois); 76 Fed. Reg. 72097. 108 (Nov. 22. 2011) 

(effective December 31. 2011); 75 Fed Reg. 71033.42 (Nov. 22. 2010) 

(effective December 31. 2010). Thus. this subsection (a) has been 

obsolete since December 31. 2012. 

BOARD NOTE: This subsection (a) is derived from 40 CFR 50.12 (2012). 

b) 2008 Primary and Secondary Three-Month Average NAAQS for Lead. 

1) The 2008 prima1y and secondary tln·ee-month average NAAQS for lead 

and its compounds is 0.15 f!gim3

• arithmetic mean concentration over a 

three-month period. measured in the ambient air as lead by either of the 

following; 

A) An FRM based on appendix G of 40 CFR 50. incol]lorated by 

reference in Section 243.108. and designated by USEPA and listed 

in the List of Designated Methods. incorporated by reference in 

Section 243.108 or; 

Bl An FEM designated by USEP A and listed in the List of Designated 

Methods. incmporated by reference in Section 243.108. 

2) The 2008 primary and secondary tln·ee-month average NAAQS for lead 

are met when the maximum arithmetic tln·ee-month mean concentration 

for a three-year pe1iod. as dete1mined in accordance with appendix R of 

40 CFR 50. incmporated by reference in Section 243.108. is less than or 

equal to 0.15 f+g/m3

. 

BOARD NOTE: This subsection (b) is derived from40 CFR 50.16 (2012). 

(Source; Amended at 37 Ill. Reg. ____ , effective _________ _; 

Section 243.APPENDIX A Rule into Section Table (Repealed) 

SECTIOJ>I 

243.102 

243.103 

243.104 

AJ3J3 endiK C 

243.108 
3) USEPA has stated in corresponding 40 CFR 50.10(c) that the 1997 

prima1y and secondary eight-hour NAAQS for ozone set forth in 

subsection (b)(l) of this Section will no longer apply to an area for 

transportation conformity pmposes one year after the effective date of 

USEPA designation of that area pursuant to 42 USC 7407 for the 2008 

primary and secondary eight-hour NAAQS set forth for ozone in 

subsection (c)(l) of this Section. The 1997 primary and secondary eighthour NAAQS for ozone set forth in this subsection (b) will remain 

applicable to all areas for all other pmposes notwithstanding the 2008 

primary and secondary eiwt-hour NAAQS for ozone set fo11h in 

subsection (c) of this Section or the USEPA designation of areas for that 

2008 primary and secondary eight-hour NAAQS for ozone. 

BOARD NOTE: USEPA has codified area designations and 

classifications with respect to the 2008 primary and secondary NAAQS 

for ozone in 40 CFR 81.314. When USEP A has taken action and the 

conditions of subsection (b )(3) have been fulfilled. or USEP A has 

removed 40 CFR 50.1 0. the Board will remove obsolete 1997 primary and 

secondary one-hour or eight-hour NAAQS for ozone from this subsection 

hl 

BOARD NOTE: This subsection (a) is detived fi-om 40 CFR 50.10 (2012). 

b) 2008 Ptimm-y and Secondary Eight-Hour NAAQS for Ozone. 

I) The 2008 primary and secondary eiwt-hour NAAOS for ozone is 0.075 

ppm. daily maximum eight-hour average. measured by an FRM based on 

appendix D to 40 CFR 50. incmporated by reference in Section 243.108. 

and designated by USEPA and listed in the List of Designated Methods. 

incoroorated by reference in Section 243.108. or an FEM designated by 

USEPA and listed in the List of Designated Methods. incoroorated by 

reference in Section 243.108. 

2) The 2008 primary and secondary eight-hour NAAQS for ozone ambient 

air qualitv standards are met at an ambient air quality monitoring site 

when the tlu·ee-year average of the annual fom1h-highest daily maximum 

eight-hour average ozone concentration is less than or equal to 0.075 ppm. 

as determined in accordance with appendix P to 40 CFR 50. incmporated 

by reference in Section 243.108. 

BOARD NOTE: This subsection (b) is derived from 40 CFR 50.15 (2012). 

(Source: Amended at 37 Ill. Reg. ____ , effective _________ _, 
Section 243.126 Lead 

a) 

19) 

Staaaanl. The primary aaa seeeaaary aawieflt air Eft~ality staaaaras fer leaa aaa 

its eompoeaas Rleaserea as elemefltalleaa are 9.1 § Ft!ifm~, maJtirn.effl rolliag tlB:ee 

ll'lOHtfl a-verage FBeaserea aaa cletermiaecl over a tl1£ee year pe1iecl. 

~i!easereFBeflt Methocl. for cletennffiiag eoafenl'laaee 'Nitli tl!e aHthieflt air Ejt~ality 

staaElar8s fer leaEl aaEl its eOHlflOHBEis, leaEl aaEl its SOffij30UHEls shall be a1easured 

as eleffleatalleacll9y fecleral OEjtlivaleat Rletl!ecll9aseclea 49 CPR §9 appeaclilt G 

aacl clesignatecl ia aeeorclaaee with 49 CPR §3, er lly aa OEjtlivaleat FBetllocl 

clesigaatecl in aeeorclaaee witl! 49 CFR §3 (iaeorperatecll9y refereaee ffi Seetioa 

243.1Q8) .. Ceai!Jliaaee witl! the primary aaa seeeaclary anwieflt air Ejt!ality 

staaclarcls sl!allee cletenninecl ia aeeorclaaee witl! 4Q CFR §Q, appeacliK R 

(ineorporatecll9y refureaee ia Seetioa243.1Q8). 

a) 1978 P1imary and Secondary Quarterly Average NAAQS for Lead. 

1) The 1978 primary and secondary quarterly average NAAQS for lead and 

its compounds. measured as elemental lead by an FRM based on appendix 

G to 40 CFR 50. incorporated by reference in Section 243.108. and 

designated by USEP A and listed in the List of Designated Methods, 

incorporated by reference in Section 243.108, or by an FEM designated by 

USEPA and listed in the List of Designated Methods. incorporated by 

reference in Section 243.108. is 1.5 ug/m3

• maximum arithmetic mean 

averaged over a calendar quarter. 

2) The 1978 primary and secondary qumterly average NAAQS for lead set 

fmth in this subsection (a) will remain applicable to all areas 

notwithstanding the 2008 primary and secondary qumterly average 

NAAQS for lead in subsection (b) of this Section. The 1978 primm-y and 

secondary quarterly average NAAQS for lead set forth in this subsection 

(a) will no longer apply to an area one year after the effective date of the 

designation of that area by USEPA pursuant to 42 USC 7407 for the 2008 

primary and secondary three-month average NAAQS for lead set fmth in 

subsection (b) of this Section: except that for areas designated 

nonattainment for the 1978 primary and secondmy qumterly average 

NAAQS for lead set forth in this subsection (a) as of January 12, 2009. the 

1978 primarv and secondary NAAQS for lead set fmth in this subsection 

(a) will apply until USEP A has approved an implementation plan for that 

area pursuant to 42 USC 7514 providing for attainment or maintenance of 

the 2008 primary and secondary three-month average NAAOS for lead set 

forth in subsection (b) of this Section. 

BOARD NOTE: The Board substituted "January 12. 2009" for the openended language in cmTesponding 40 CFR 50.12(b) relative to the effective 

date of 40 CFR 50.16. January 12. 2009 is the effective date recited at 73 
J% 243.107 

W+ 243.121 

W& 243.122 

J@ ReJ3ea1eEI 

,}W 243.123 

M+ 243.124 

J.P- 243.125 

J.g 243.126 

(Source: Repealed at 3 7 Ill. Reg. , effective----------' 

Section 243.APPENDIX B Section into Rule Table (Repealed) 

SBCTIOJ>! 

243.101 

243.102 JM 

243.103 w;>, 

243.104 JW 

243.106 ~ 

243.107 J% 

243.121 W+ 

243.122 W& 

243.123 ,}W 

243.124 M+ 

243.125 ~ 

243.!26 J.g 

(Source: Repealed at 3 7 Ill. Reg. , effective --------' 

Section 243.APPENDIX C Past Compliance Dates (Repealed) 

elleej'lt as ether::ise HeteEI, eoffij3lianee '.vith this Pa1t was reEjtlireEI Ame 26, 1973. 

(Source: Repealed at 37 Ill. Reg. ___ , effective----------' 
Section 243.TABLE A Schedule of Exceptional Event Flagging and Documentation 

Submission for New or Revised NAAQS 

Air guality 

NAAQS data collected Event flagging & Detailed 

(Levell for calendar initial descri11tion documentation 

Regulatory Citations year deadline submission deadline 

2006 24-hour PM2.5 2004-2006 October I, 2007 A11ril 15. 2008 

(35 ug/m3

) 

Section 243.120(c)(l) 

40 CFR 50.13(a) 

71 Fed. Reg. 61144 (Oct. 

17. ?006) 

2008 eight-hour ozone 2005-2007 June 18. 2009 June 18. 2009 

(0.075 @m) 2008 June 18. 2009 June 18. 2009 

Section 243.125(c)(l) 2009 60 days after the end 60 days after the end 

40 CFR 50.15(a) of the calendar gumter of the calendar guatter 

73 Fed. Reg. 16436 (Mar. in which the event in which the event 

27. 2008) occuned or Febmary occuned or Febmary 

5. 2010. whichever 5. 2010. whichever 

date occmTed first date occmTed first 

2010 one-hour nitrogen 2008 July I. 2010 J anua!:Y 22. 20 II 

oxides (as NOJ). 2009 July I. 2010 Janua!:Y 22. 2011 

000 @b) 2010 A11ril I. 20 II July I. 2010 

Section 243.124(b) 

40 CFR 50.ll(b) 

75 Fed. Reg. 6474 (Feb. 9. 

2010) 

2010 one-hour sulfur 2008 October I. 2010 June I. 2011 

oxides (as SOJ). 2009 October I. 20 I 0 June I. 2011 

(75 @b) 2010 June I. 2011 June I. 2011 

Section 243.122(c)(l) 2011 60 days after the end 60 days after the end 

40 CFR 17(a) of the calendar guatter of the calendar guarter 

75 Fed. Reg. 35520 (June in which the event in which the event 

22, 2010) occuned or March 31. occuned or March 31, 

2012. whichever date 2012. whichever date 

occuned frrst occured first 

BOARD NOTE: Derived from table I to 40 CFR 50.14(c) (2012). USEPA noted that the 

information in this table of revised deadlines only a@ lies to data that USEP A will use to 

establish the final initial designations for new or revised NAAQS. USEPA stated that the 

general schedule in this table aJ1J1lies for all other J1utposes. most notably. for data that USEPA 
will use for redesignations to attainment. Cmresponding table 1 to 40 CFR 50.14(c)(2) cites the 

2010 one-hour NAAOS for nitrogen oxides as "80-100 PPB. final level TBD" and the 2010 onehourNAAOS for sulfur oxides as "80-100 PPB, final level TBD." The adopted 2010 one-hour 

NAAOS forNOx at 40 CFR 50.11([) is 100 ppb and the adopted 2010 one-hourNAAOS for S02 

is 75 ppb. The Board has used the actual NAAOS for these contaminants in this Table A. 

Fmther, cmresponding table 1 to 40 CFR 50.14(c) includes endnotes "a" and "b" indicate 

whether dates for NO, and SO, are changed or unchanged, which the Board has omitted, since 

endnotes will serve no purpose in the Illinois regulations. 

(Source: Added at 37 Ill. Reg. ___ , effective _________ _; 

IT IS SO ORDERED. 

I, John Theniault, Clerk of the Illinois Pollution Control Board, ce1tify that the Board 

adopted the above opinion and order on July 25,2013, by a vote of 4-0. 

John Theniault, Clerk 

Illinois Pollution Control Board