IN" THE MATTER OF: 

ILLIN"OIS POLLUTION CONTROL BOARD 

May 16,2012 

) 

) Rl3-ll 

. IEPA.ATTACHMENTN0.1- . 

NATIONAL AMBIENT AIR QUALITY 

STANDARDS, USEPA REGULATIONS 

(through December 31, 2012) 

) (Identical-in-Substance Rulemaking- Air) 

) 

Proposed Rule. Proposal for Public Comment. 

OPWION 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 conform with National Ambient Air Quality 

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

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 a proposal for public comment that would replace all existing 

Illinois ambient air quality standards with standards derived directly from the federal NAAQS 

codified in 40 C.P.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 counterparts, 

as "identical-in-substance" is defined by Section 7.2(a) of the Environmental Protection Act 

(Act) (415 ILCS 5/7.2(a) (2012)). 

Section 10(H) of the Act (415 ILCS 5/!0(H), as added by P.A. 97-945 (eff. Aug. 10, 

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

specifYing the maximum permissible short-term and long-term concentrations of various 

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

ambient air quality standards 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). In addition, Section 9.l(e) of the Act requires the Board to conduct this rul=aking 

pursuant to Section 7.2(b) of the Act (415 ILCS 5/7.2(b) (2012)) for adopting rules that are 

"identical in substance" to the federal requirements. 

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

Administrative Procedure Act (APA) (5 ILCS 100/5-1-5(c)(l) (2012)) also provide that Title VII 

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

proceeding. Accordingly, the Board will not adopt a "First Notice" proposal, or a "Second 

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

as provided in Section 1 O(H) of the Act, and as explained in the two following segments of this 

opinion and order, the Board, before adopting final rule amendments, will provide notice of this 

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 standards. 
2 

mlemaking proposal in the Illinois Register, hold one public hearing on the proposal as required 

by the federal Clean Air Act (33 U.S.C. § 7410(a) (2011)), and allow for public comment. 

The Board reserved this docket to accommodate the initial set of amendments necessa1y 

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

amended by USEP A through December 31, 2012. Board action is necessmy to mnend the 

Illinois mnbient air quality standards to conform with the NAAQS adopted by USEPA, as 

amended through calendar year 2012. 

The Board prefaces this opinion with procedural matters. First, the Board provides 

information on the public comment period. Second, the Board describes facts relative to a 

scheduled public hearing for this proceeding. Third, the Board sets forth the timetable for 

completing this mlemaking. The substantive discussions follow the procedural matters. 

PUBLIC COMMENTS 

The Board invites public comment on the proposed mnendments. The Board will receive 

public comments until at least 45 days after a notice of these proposed amendments appears in 

the Illinois Register. Anyone may file a public comment with the Board at: 

Office of the Clerk 

Pollution Control Board 

James R. Thompson Center 

100 W. Randolph Street, Suite 11-500 

Chicago, Illinois 6060 I 

Alternatively, an interested person may file electronically using the Clerk's Office On-Line 

(COOL) system, linked on the Board's Web page, at www.ipcb.state.il.us. 

All comments relating to this mlemaking, whether filed physically or electronically, 

should clearly refer to docket number Rl3-ll. 

All filings with the Clerk of the Bom·d must be served on the hearing officer and on those 

persons on the Service List for this rulemaking. The service list is available on the Board's Web 

page. Before filing any document with the Clerk, please check with the Clerk's Office to 

confirm that you are using the most recent version of the Se1vice List. The hearing officer 

assigned to this rulemaking is Michael J. McCambridge (312-814-6924, 

michael.mccambridge@illinois.gov). 

FEDERALLY REQUIRED 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 contmninants 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.P.R. 51.102 and appendix V (2012). 
3 

The Board has scheduled a public hearing to occur in this rulemaking 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. Hearing infmmation follows: 

11:00 a.m., June 26,2013 

Sangamo Building, Room 1119N 

1021 North Grand Avenue 

Springfield, Illinois 

The record in this docket will include all documents pe1taining to this proceeding. All 

documents in the record are publicly available for inspection and copying as provided in 2 Ill. 

Adm. Code 2175 (2012). The documents are also freely available online at the Board's 

webpage: www.ipcb.state.il.us. 

The record will not include a copy of the following documents, which are all otherwise 

publicly available: 

• The Federal Register notice relating to this action (referenced elsewhere in this opinion 

and order); 

• Federal statutes and regulations referenced in this opinion and order; and 

• Illinois statutes and regulations referenced in this opinion and order. 

The Board will cause publication of a Notice of Public Infmmation on Proposed Rules in 

the Illinois Register. In that Notice, the Board will describe the hearing date and time outlined 

above and set forth infmmation to aid members of the community to obtain and review 

documents and participate in this proceeding. The Board will try to have that publication occur 

simultaneous with publication of the Notice of Proposed Amendments. The notices published 

relative to this proceeding will request that interested persons direct questions to the following 

person: 

Michael McCambridge, Staff Attomey 

Pollution Control Board 

I 00 West Randolph Street, Room 11-500 

Chicago, Illinois 6060 I 

219-814-6924 

michael.mccambridge@illinois.gov 
4 

The notices published relative to this proceeding will direct interested persons to request 

documents from or submit documents to the following person: 

John T. Therriault, Assistant Clerk of the Board 

Pollution Control Board 

100 West Randolph Street, Room 11-500 

Chicago, Illinois 6060 I 

219-814-3629 

john.theniault@illinois.gov 

After the hearing and public comment period, the Board will promptly issue an opinion 

and order adopting final rule amendments. The Board will then file the amendments with the 

Office of the Secretary of State, and a Notice of Adopted Amendments will appear in the Illinois 

Register. Any Agency submission of the associated SIP revision to USEPA will follow that 

Notice. 

DUE DATE AND SCHEDULE FOR COMPLETION 

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

US EPA 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 of P .A. 97-945, the Board is interpreting 

that this initial round of amendments must be completed before August I 0, 2013. Fulfilling the 

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

Due date: 

Proposal adopted date: 

Publication submission deadline: 

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 

May20, 2013 

May 31,2013 

June 26, 2013 

July 15, 2013 

July 25, 2013 

August 5, 2013 

August 15,2013 

This estimated timetable of intermediate activities towards completion of the 

amendments has time added to allow for any minor unforeseen delays in finalizing the 

amendments. Nevertheless, progress could occur more slowly-up to the statutory deadline of 

August I 0, 20 13-due to presently unforeseen events. 

OVERVIEW OF THE FEDERAL NAAQS AND THIS PROCEEDING 

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

standards identical-in-substance to the NAAQS adopted by USEPA. Today's proposal includes 
5 

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 7 

Overview of the Federal NAAQS 8 

The Section 1 O(H) Mandate and the Federal Regulations Included 8 

Replacing the Existing Illinois Ambient Air Quality Standards 9 

Retaining the Existing Illinois Structure: Combining a Ctiteria 10 

Pollutant 

Use of the Singular or Plural to Refer to Primary and Secondary 10 

NAAQS 

Standardized Naming of Each NAAQS 10 

Removal of Two Illinois Rules 12 

Removal of the "Nondegradation" Rule 13 

Removal of the "Monitoting" Rule 13 

Inclusion ofPresctibed Methods, Required Interpretations, and Special- 14 

Case Methods 

List of Designated Methods 14 

Incorporation of Designated Methods 15 

References to Methods in the Text of the NAAQS 16 

Standardization ofTerms: FRMs, FEMs, and List of Designated 16 

Methods 

Codified and Non-Codified FRMs 17 

Non-Codified FEMs 19 

The Difference Between FRMs and FEMs 19 

Inte1pretations: Conventions for Data Management and Analysis 20 

The Special Case FRMs of Appendices B, 0, and Q 21 

Appendix B: FRM for Total Suspended Pmticulate Matter 21 

Appendix 0: FRM for Coarse Particulate Matter (PM10_2_5) 22 

Appendix Q: FRM for Lead in Particulate Matter (PM10) 23 

Summary Tabulation of the NAAQS and Supp01ting Appendices 23 

NAAQS for Sulfur Oxides 23 

NAAQS for PM10 and PM25 24 
6 

NAAQS for Carbon Monoxide 24 

NAAQS for Ozone 25 

NAAQS for Nitrogen Oxides 25 

NAAQS for Lead 26 

Non-NAAQS Required Monitoring 26 

Summary re Incorporation of the FRMs, FEMs, and Interpretations 26 

Codified FRMs 26 

Non-Codified FRMs 26 

Non-Codified FEMs 27 

Interpretations 27 

The Special-Case FRMs 27 

Omission of Ancillary Federal Regulations in 40 C.P.R. 53, 58, and 81 27 

Revisions to USEPA Defmitions/Definitions Added 28 

Shifted Meanings and Revisions to the Preamble 28 

Changes in Defmed Tem1s 29 

Added Defined Terms 29 

Omitted Defmed Terms 30 

USEP A Rules Added/State Provisions Removed 31 

Incorporation of the NAAQS for the Six Critetia Pollutants 33 

Section 243.120: Pm1iculate Matter 33 

Section 243.122: Sulfur Oxides 37 

Sunset Clause for the 1971 Prinlmy 24-Hour NAAQS for Sulfur 39 

Oxides 

Option I: Retain the Entire Federal Text with Minimal Deviation 40 

Option 2: Replace the Statement of Inapplicability and Delete One 41 

Exception Statement. 

Option 3: Replace the Statement of Inapplicability with a Statement 42 

That the Board Will Remove the 1971 NAAQS When Conditions 

Are Fulfilled 

Option 4: Replace the Statement of Inapplicability with a Statement 43 

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 43 

Selection of Option 3 43 
7 

Section 243.123: Carbon Monoxide 44 

Section 243.124: Nitrogen Oxides 46 

Section 243.125: Ozone 47 

Sunset of the 1979 Primary and Secondary One-Hour NAAQS for 50 

Ozone 

Pa11ial Sunset of the 1997 Primary and Secondary Eight-Hour 50 

NAAQS for Ozone 

Section 243.126: Lead 50 

1978 Primary Calendar Quarterly Average NAAQS for Lead 52 

Non-Inclusion of the 2012 NAAQS for PM2.5 and dPM10 52 

Requests for Public Comments 55 

Deviations from the Literal Text of the Federal Amendments and Non- 56 

Federally De1ived Corrections and Clarifications 

Tabulations of Deviations from the Literal Text of the Federal Amendments 56 

and Miscellaneous Board Housekeeping Amendments 

Table 1: 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 

57 

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 tlies 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 stmcture may occur for a valiety of reasons and will be noted 

as needed below. Where more st1ingent pre-existing State standards exist that will continue in 

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

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

Code 810, 811, and 814), R93-10 (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 stringent pre-existing State regulations within the body of 

new federal requirements). 
8 

Overview of the Federal NAAOS 

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

contribute 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 p1imary and 

secondary NAAQS. A primary 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 advismy committee 

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

To date, USEP A has designated six "criteria" pollutants for establishment of primary and 

secondary NAAQS: 

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

Lead (Pb) (see 40 C.P.R. 50.12 and 50.16 (2012)); 

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

Ozone (OJ) (see 40 C.P.R. 50.9 and 50.15 (2012)); 

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

Particulate matter (PM) (see 40 C.P.R. 50.6 (1986)); 

Pm1iculate matter with an aerodynamic diameter of 10 micrometers (f.lm) or less 

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

Particulate matter with an aerodynamic diameter of2.5 micrometers (f.lm) or less 

(PM2.5) (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 10(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 

517.2 and 10 to require the Board to adopt mles 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 USEPA-approved monitoring 

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

50.5(b), and 50.17(c) (2012) (specifying the methods for the NAAQS for sulfur dioxide). The 

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

2 The stated purpose was to facilitate adoption of the federal NAAQS and the air permitting 

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. 
9 

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

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

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

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

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

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

50.12(b) (2012) (cmresponding with 35 Ill. Adm. Code 243.122(a)(5), the 1971 primmy 

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 p1imary and secondaryNAAQS 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 

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

op. at 4-5, 14 (initial Board adoption of mnbient 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). 

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 Oualitv 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 current federal NAAQS. 

The mandate of Section lO(H) of the Act (415 ILCS 5/lO(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 further allows the Board to adopt more stringent State 

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

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

and stmcture of the cmresponding 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), 

R93-10 (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 structure 

and language of each federal NAAQS. Fmther, 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 proposes to replace the structure and language of the existing 

Illinois ambient air quality standards with that of the federal NAAQS. 
10 

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 tlu·ee 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 criteria pollutant into a single 

provision. Thus, the primary and secondary NAAQS for PM10 and PM2.s from 40 C.F.R. 50.6, 

50.7, and 50.13 are combined in Section 243.120; the NAAQS for sulfur oxides fi·om 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 (conesponding 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 (conesponding 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 p1imary and secondary NAAQS where both are embodied in a 

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

PM10) and 50.9(a) (1997 prin1ary 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 ptimary and 

secondary standard. See, e.g., 35 Ill. Adm. Code 243.120(a)(l) and 243.125(a)(1) 

(conesponding 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 secondaryNAAQS. See 40 C.F.R. 50.ll(b) and (c) (2012). See 35 Ill. Adm. Code 

243.124(b) and (c) (conesponding with 40 C.F.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.F.R. 50.8(a)(1) and (a)(2) (2012). 

Standardized Naming of Each NAAOS. 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 

average," "quarterly average" (or "three-month average"), "24-hour," "eight-hour," "three-hour," 

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

3 The monitoring for each NAAQS occurs over specific petiods, 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 repmted and considered on a quarterly or annual-average basis. See, 

e.g., 40 C.F.R. 50.4(a) (1971 ptimary annual average NAAQS for sulfur oxides) and 50.12(a) 
11 

particular criteria pollutant-i.e., "carbon 1nonoxide," "lead," :nitrogen oxides," "ozone," 

"PM10" or "PM2.

5,'' 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 structured 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. 

Using the above-described convention, the standardized NAAQS names (together with the 

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

Patiiculate matter (PM): 

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

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

PMw" 

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

NAAQS for PMz.s" 

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

PM2.s" 

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

NAAQS for PMz.s" 

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

PM2.s" 

Sulfur oxides: 

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

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

oxides" 

"1971 primary24-hourNAAQS for sulfur oxides" 243.122(a) 50.4 

"1971 secondmythree-hourNAAQS for sulfur 243.122(b) 50.5 

oxides" 

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

short-tenn basis of a one-, three-, eight-, or 24-hour average. See, e.g., 40 C.F.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 short-te1m 

averages, the Board has omitted the word "average" when creating a standardized name. 
12 

"2010 p1imary one-hour NAAQS for sulfur 243.122(c) 

oxides" 

Carbon monoxide: 

Standardized Name 35 Ill. Adm. Code 

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

monoxide" 

Nitrogen oxides: 

Standardized Name 35 Ill. Adm. Code 

"1971 prima1y annual average NAAQS for 243.124(a) 

nitrogen oxides" 

"2010 p1imary one-hour NAAQS for nitrogen 243.124(b) 

oxides" 

"1971 secondary annual average NAAQS for 243.124(c) 

nitrogen oxides" 

Ozone: 

50.17 

40C.F.R. 

50.8 

40 C.F.R. 

50.11(a) 

50.1l(b) 

50.1l(c) 

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

"1997 primmy and secondary one-hour NAAQS 

for 0 3" 

"1997 primary and secondary eight-hour NAAQS 

for 0 3" 

"2008 primary and secondm·y eight-hour NAAQS 

for 0 3" 

Lead: 

243.125(a) 50.9 

243.125(b) 50.10 

243.125(c) 50.15 

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

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

NAAQS forlead" 4 

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

NAAQS for lead" 

Removal of Two Illinois Rules 

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

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

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

as is discussed beginning on page 52 of this opinion and order. 
13 

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

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

Environmental Protection Act. The Board adopted the mle from earlier rules of the Air Pollution 

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

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

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

than that brief description. The Board proposes removing the non-degradation clause of 35 Ill. 

Adm. Code 243.104 because (1) it might conflict with a newly added federalmle; (2) it is not 

necessary in the context ofNAAQS; and (3) it is not possible to con·ect 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 proposes to incorporate at 35 Ill. Adm. Code 

243.102(c). That statement, added to the Illinois rules, is as follows: "The promulgation of 

primary and secondary NAAQS must not be considered in any manner to allow significant 

deterioration of existing air quality in any pmtion of this State." 35 Ill. Adm. Code 243.102(c). 

To the extent that the clause relates to the NAAQS themselves, the differences between the 

Illinois rule and the newly added federal statement could conflict. Furthermore, by incorporating 

the federal language in 35 Ill. Adm. Code 243.102(c), the Illinois rules 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 principle embodied in the federal Prevention of Significant Degradation 

(PSD) requirements. See 42 U.S.C. §§ 7470 et seq. (2011); 40 C.P.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 

rule in this way in the context of this identical-in-substance proceeding. 

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

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

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

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

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

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

while impmtant to implementation of the NAAQS, this provision is not a necessary segment of 
14 

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

the NAAQS. Fmther, 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/IO(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-implementing. See, e.g., 40 C.F.R. 50.10(a) and 

50.ll(a) (2012). Thus, no Illinois provision is necessary in this regard. Third, the vmious 

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

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

referenced in several of the methods and procedures required for monitoring. See Appendices AI, 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). 

Nevertheless, 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 ofthis Pmt must be 

perfmmed 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. 

USEP A has approved multiple methods for use in demonstrating compliance with each 

NAAQS. The methods that the standm·ds require for dete1mining 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 authmity to itself for approval 

of alternative methods. 

The approved methods are oftlu·ee types: (1) 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 further allow the alternative use of another USEPA-designated reference method. 

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

fu1ther 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 lllinois NAAQS rules. 

List of Designated Methods. US EPA 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 

5 The Board would nmmally 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 USEPA as compliant with 40 C.F.R. 58. 
15 

the date of Federal Register publication. 40 C.P.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.P.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 information items: (1) 

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 infmmation. The List 

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

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

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 Monitming Technology Infom1ation 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 11,2012 and October 5, 

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

55832 (Sept. 11, 2012). 

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

USEP A 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 

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 12,2011, April!, 2011, and Febmary 1, 2011. 
16 

check the TTN-AMTIC website for any updates to the list or USEPA 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. 

Refet·ences to Methods in the Text of the NAAQS. 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.P.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), 50.1 O(a), 50.11 (a) and ( d)(2), 50.13(a)(l) 

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.P.R. 50.12(a) (2102) 

(lead). 

The Illinois NAAQS mles will specify use of methods "designated by USEP A and listed 

in List of Designated Methods, incorporated by reference in Section 243.1 08." 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)(l)(A), and (b)(l)(B). USEPA alone has authority to designate 

monitoring methods. See 40 C.P.R. 53.8(a), 53.1l(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 countetparts. 

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 ofUSEPA-designated methods, the Board has combined 

usage from two segments of the USEP A regulations: (I) the NAAQS mles themselves; and (2) 

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

standardized tem1s "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 conesponding 40 C.P.R. 50.1(±), and "federal reference method" in 40 

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

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

NAAQS-derived regulations. This is without regard to whether the method is codified as an 
17 

appendix to 40 C.F.R. 50 or the method is a USEP A-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 USEPA-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 USEP A 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 ofte1ms. The Board intends that the Illinois NAAQS mles have 

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

Most of the NAAQS provisions describe the permissible 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)(1) (PM25), 50.8(b)(1) (carbon 

monoxide), 50.9(a) (ozone), 50.1 O(a) (ozone), 50.11( d)(1) (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 te1m "an FRM based on [the 

reference method cited in] appendix ... and designated by USEP A." 

The Board has followed the federal language very closely in the con·esponding Illinois 

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

paragraphs: (1) the Board standardized usage of the defined term "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 corresponding 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)(1)(A), and (c)(1)(A) (PM10 and PM25); 243.123(b)(l) (carbon monoxide); 

243.124(d)(l) (nitrogen oxides); and 243.125(a)(1), (b)(l), and (c)(1) (ozone). 

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

ambiguity concerns 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. 
18 

The NAAQS for carbon monoxide, ozone, nitrogen oxides, PM10, and PM25 require use 

of an FRM "based on" an associated appendix to 40 C.P.R. 50. See 40 C.P.R. 50.6(c)(1) (2012) 

("based on appendix J" for PM10); 40 C.P.R. 50.7(a)(l) and 50.13(a)(1) (2012) ("based on 

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

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

40 C.P.R. 50.11 (d)(!) (20 12) ("based on appendix F" for nitrogen oxides). Fmther, the List of 

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

relative to carbon monoxide, ozone, nitrogen oxides, PM10, and PM25, respectively. The general 

rules relative to FRM designations for PM10, 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.P.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 term 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-1 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 primary one-hour NAAQS for sulfur oxides uses the term 

"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 50.16(a)(l) 

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

Designated Methods, at 42. Fmther, 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. Further, the 

Board observes that only two of the codified FRMs are included in List of Designated Methods. 
19 

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 mles, the Board cannot mitigate any potential for 

ambiguity. 

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

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

unifmm language: "an equivalent method designated in accordance with part 53 of this chapter." 

See 40 C.F.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.F.R. 50.12(a) (2012)); and (2) the 2010 

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

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

Designated Methods, at 4-9 (11 for PM10), 10-15 (17 for PM2.5), 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 prima1y 

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

the use of an FRM. See 40 C.F.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). Fmther, the List of Designated Methods includes 23 FEMs for 

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

The Board has unifmmly used "an FEM designated by USEPA and listed in List of 

Designated Methods, incorporated by reference in Section 243.1 08" throughout all of the 

NAAQS, except for the 1997 primary 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)(l), and (c)(l); 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)(l). 

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 authorize 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 PM2.5: 
20 

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

measurements of ... [critetia 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 ... [ critetia pollutant] measurement technologies for this 

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

[criteria pollutant] measurements comparable to reference measurements under a 

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

The Board observes that the federal rules divide FEMs for PM25 into three classes: Class 

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

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

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

differs. See 40 C.F.R. 53.3(a)(2) and (a)(3) (2012); table C-4 to subpa1t C of 40 C.F.R. 53 

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

performance tests to which candidate equivalent methods are subjected .... " 62 Fed. Reg. 

38764, 66 (July 18, 1997). Since the classes ofFEMs 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 detetmine compliance with the NAAQS. All of these inte1pretations are embodied in an 

appendix to 40 C.F.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.F.R. 50 "to determine when the expected number of days per 

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

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

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

determination of compliance using the "data handling conventions and 

computations" of Appendix I to 40 C.F.R. 50. See 40 C.F.R. 50.10(b) (2012); 

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

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

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

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

(introductory paragraph). 

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

for PMz 5 (four NAAQS) require determination of compliance using the "data 

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

C.F.R. 50.7(b) and 50.!3(b) (2012); Appendix N to 40 C.F.R. 50 (2012) 

(introductory paragraph). 
21 

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.F.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 NAAQS 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) (2012); Appendix R to 40 C.P.R. 50 

(2012) (introductory paragraph). 

Appendix S: The 1971 primary annual average and 2010 mimary one-hourNAAQS 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. 50.11(e) and (f) (2012); Appendix S to 40 C.P.R. 50 (2012) 

(introductory paragraph). 

Appendix T: The 2010 primary one-hour NAAQS for sulfur oxides requires detennination 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 primary 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 qua1ierly average NAAQS for lead (see 40 C.P.R. 50.12 

(2012)). 

The Special Case FRMs of Appendices B. 0, and 0. 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 (or Total Suspended Particulate Matter. An old NAAQS for 

particulate matter (PM) formerly 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 USEPA subsequently replaced the 

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

Appendix B for PM. USEPA 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 1, 1987). 
22 

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 III. 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_54, USEPA once proposed, 

yet declined to adopt a NAAQS for coarse particulate matter (PM10.25). See 71 Fed. Reg. 61144, 

94 (Oct. I 7, 2006); 71 Fed. Reg. 2620, 98 (Jan. I 7, 2006) (proposing a 24-hour standard of70 

f1g/m3 as 40 C.P.R. 50.13(a)(2)(i)). USEPA, however, adopted the proposed FRM for PM10.2.5 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. I 7, 2006) (accompanying amendments to 

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

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

on PM10-2.5 air quality and health effects and in promoting the conunercial 

development of FEMs. In a separate final rule ... [US]EP A is promulgating a 

requirement that States deploy about 60 FRM or FEM PM10_25 monitors as pm1 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, 

USEPA required all states to establish and operate at least one NCore 8 monitoring site. USEPA 

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

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

Monitoring for PM10.2.s is required at each NCore site. See 40 C.P.R. 58.12(±)(1) (2012); 

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

"NCore"). 

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

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

Appendix 0 to 40 C.P.R. 50. This is despite the fact that Appendix 0 is not part 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.P.R. 

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

NCore system pursuant to 40 CPR 58." 

8 Defined as the "N a tiona! Core multipollutant monitoring stations" that monitor PM25, speciated 

PM2.s PM10.2.s, ozone, sulfur dioxide, carbon monoxide, nitrogen oxides, lead, and basic weather 

data. 40 C.P.R. 58.1 (2012). 
23 

Appendix 0: FRM fOr Lead in Particulate Matter (PM102. US EPA once proposed 

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

coarse pmticulate 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. USEPA, 

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

to establish compliance where the levels of lead 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 secondmy three-month average NAAQS for 

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

See Appendix R to 40 C.P.R. 50 (2012), at 'i[l(a); 73 Fed. Reg. at 67019-21. 

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

inclusion of Appendix Q in the Illinois NAAQS mles. Appendix Q provides an alternative 

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.P.R. 50. 

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. 

NAAQS (Or Sulfur Oxides: 

NAAQS: 1971 primary annual average NAAQS for sulfur oxides 

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

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

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

Interpretation specified: None 

NAAQS: 1971 primary 24-hourNAAQS for sulfur oxides 

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

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

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

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

Citations: 40 C.P.R. 50.5(b)/35 Ill. Adm. Code 243.122(b)(2) 

Interpretation specified: None 

NAAQS: 2010 primary one-hour NAAQS for sulfur oxides 

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

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

Citations: 40 C.P.R. 50.17(c)/35 Ill. Adm. Code 243.122(c)(3) 
24 

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

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

NAAOS for PM1o and PM,5 : 

NAAQS: 1987 primary and secondary 24-hour NAAQS for PM10 

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

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

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

NAAQS: 1997 primary and secondary annual average NAAQS for PM, 5 

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

FRM 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) 

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) 

FRM 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) 

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: 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. Code243.120(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) 

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(c)/35 Ill. Adm. Code 243.120(c)(3) 

NAAOS for 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) 

FRM 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) 
25 

Interpretation specified: None 

NAAQS: 1971 primary one-hour NAAOS for carbon monoxide 

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

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

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

Interpretation specified: None 

NAAOS (Or Ozone: 

NAAQS: 1997 PJimary and secondmy one-hour NAAQS for ozone 

Citations: 40 C.F.R. 50.9(a)/35 Ill. Adm. Code 243.125(a)(l) 

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

Citations: 40 C.F.R. 50.9(a)/35 Ill. Adm. Code 243.125(a)(l) 

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

Citations: 40 C.F.R. 50.9(a)/35 Ill. Adm. Code 243.125(a)(l) 

NAAQS: 1997 primary and secondary eight-hour NAAQS for ozone 

Federal citation: 40 C.F.R. 50.10(a)/35 Ill. Adm. Code 243.125(b)(l) 

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

Citations: 40 C.F.R. 50.10(a)/35 Ill. Adm. Code 243.125(b)(l) 

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

Citations: 40 C.F.R. 50.10(b)/35 Ill. Adm. Code 243.125(b)(2) 

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

Federal citation: 40 C.F.R. 50.15(a)/35 Ill. Adm. Code 243.125(c)(l) 

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

Citations: 40 C.F.R. 50.15(a)/35 Ill. Adm. Code 243.125(c)(l) 

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

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

NAAOS (Or Nitrogen Oxides: 

NAAQS: 1971 primary annual average NAAQS for nitrogen oxides 

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

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

Citations: 40 C.F.R. 50.ll(d)(l)/35 Ill. Adm. Code 243.124(d)(l) 

Intetpretation specified: Appendix S to 40 C.F.R. 50 

Citations: 40 C.F.R. 50.ll(e)/35 Ill. Adm. Code 243.124(e) 

NAAQS: 2010 primary one-hour NAAOS for nitrogen oxides 

Citations: 40 C.F.R. 50.ll(b)/35 Ill. Adm. Code 243.124(b) 

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

Citations: 40 C.F.R. 50.ll(d)(l)/35 Ill. Adm. Code 243.124(d)(l) 

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

Citations: 40 C.F.R. 50.11(£)/35 Ill. Adm. Code 243.124(f) 
26 

NAAQS: 1971 secondary annual average NAAQS for nitrogen oxides 

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

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

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

Interpretation specified: None 

NAAQS (or Lead: 

NAAQS: 1978 primary and secondary gumterly average NAAQS for lead 

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

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

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

Interpretation specified: None 

NAAQS: 2008 primary and secondary tlu·ee-month average NAAQS for lead 

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

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

Citations: 40 C.F.R. 50.16(a)(1)/35 Ill. Adm. Code 243.126(b)(1)(A) 

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

which relies on Appendix 0) 

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

Non-NAAQS Required Monitoring: 

Required by: NCore monitoring for PM10•2.s 

Citation: 40 C.F.R. 58.12(±)(1) 

FRM specified: Appendix 0 to 40 C.F.R. 50 

Citation: Appendix D to 40 C.F.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 monitming 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.F.R. 50 that codify an FRM that is cited in an NAAQS. These appendices set forth the text of 

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

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

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

L to 40 C.F.R. 50. 

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

non-codified FRMs, but not the FRMs 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 
27 

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

FRMs 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 

FEMs, 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 FRMs, with the actual method not set forth 

in full. As for the non-codified FRMs, the Board includes the FEMs 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 FEMs included in the List of Designated Methods: II 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 incmporated by reference all of the intetpretations 

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

the codified FRMs, the Board includes the intetpretations in the lllinois regulations by 

incorporation by reference of the various appendices. See 35 Ill. Adm. Code 243.108. At 

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

S, and T to 40 C.P.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.P.R. 50. As for the codified FRMs that directly suppmi 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.P.R. 50. 

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

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

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

the List of Designated Methods. See 40 C.P.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.P.R. 

53. While the methods approved by USEPA pursuant to 40 C.P.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.P.R. 53, the Board has entirely omitted 

the federal methods designations provisions from the Illinois NAAQS regulations. 

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

and maintaining monitoring networks and monitoring plans. See 40 C.P.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 mles. 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 mles. See 40 C.P.R. 58 

(2012) (authority note); 415 ILCS 5/IO(H), as added byP.A. 97-945, eff. Aug. 10,2012. For 
28 

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

requirements from the Illinois NAAQS regulations. 

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

these areas are codified in 40 C.F.R. 81. In particular, these federal rules defme 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-] anesville-Beloit Interstate), 81.98 (Burlington-Keokuk Interstate), 81.10 I 

(Metropolitan Dubuque), 81.102 (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) (20 12). These regulations further codifY USEP A'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 various 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-hour NAAQS 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 ancillary rules in the Illinois NAAQS rule. 

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

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

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

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

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

USEPA 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 incmporated 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 clarity of the rules. The following paragraphs broadly describe the revisions to the federal 

definitions. Table 1, details the revisions to the federal language. 

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

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

the preamble statement of the definitions provision. 
29 

• The Board changed the meaning of the tenn "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 term "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." 

The Board added an affirmative statement of applicability of the definitions in the 

preamble. No such statement exists in 40 C.P.R. 50.1. Rather, the corresponding federal 

preamble states that the definition of a te1m given by the Clean Air Act applies to terms 

not defmed in 40 C.P.R. 50.1. 

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

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

change the focus from 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 USEPA intended use of the Clean Air Act definitions, the Board has 

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

definitions of 35 TIL 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 purposes for the changes are two-fold: (!)to standardize use of the term and 

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

bulleted points describe the changed terms: 

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 "PEM" 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 "PRM" 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: (1) to standardize use of the te1m in the text of the rules; 

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

"Scope" provision of35 Ill. Adm. Code 243.102(a) (derived from 40 C.P.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. 
30 

and (2) to enhance the clarity of the text. The following bulleted points desctibe the added 

defined te1ms: 

The Board added a defmition of the term "micrograms per cubic meter" and the defined 

abbreviation "f1g/m3

" to enable the use of the defined abbreviation in 35 Ill. Adm. Code 

243.124(c) and 243.126(b)(l) and (b)(2) (corresponding with 40 C.P.R. 50.6(a), 50.7(a), 

and 50.9(a) (2012)), based on the definition of the abbreviation in 40 C.P.R. 50.6(a) and 

50.7(a) (2012). 

The Board added a definition of the term "milligrams per cubic meter" and the defined 

abbreviation "mg/m3

" to enable use of the defined abbreviation in 35 Ill. Adm. Code 

243.124(a)(l) and (a)(2) (based on 40 C.P.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 of 35 Ill. Adm. Code 243. The definition is based on the 

definition in "Tetms of Environment: Glossary, Abbreviations, and Acronyms" 

(December 1997), EPA 175-B-97-001, at 30. 

The Board added a definition of the term "parts per billion" and the defmed 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.P.R. 50.15(a) (2012)). 

• The Board added a definition of the term "patis per million" and the defined abbreviation 

"ppm" to enable use of the defmed abbreviation in 35 Ill. Adm. Code 243.122(a)(l), 

(a)(2), (b)(!), 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.P.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.ll(g); 50.14(c); and 50.15(b) (2012)), based on the definition of the 

abbreviation in 40 C.P.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.P.R. 50.6(c), for the purposes of35 Ill. Adm. Code 243.120(a) (conesponding with 

40 C.P.R. 50.6 (2012)). 

The Board added a definition of the term "PM2.5," based on the parenthetical definition in 

40 C.P.R. 50.7(a), for the purposes of35 Ill. Adm. Code 243.120(b) and (c) 

(corresponding with40 C.P.R. 50.7 and 50.13 (2012)). 

Omitted Defined Terms. The Board has omitted two of the federally defmed te1ms. 

The purposes for the omissions are (1) to exclude a te1m that has no present operative effect in 

Illinois (see 415 ILCS 5/7.2(a)(l) (2012)); and (2) to omit a tetm that has been substituted in the 

text of the mles with another term. The following bulleted paragraphs describe the definitions 

omitted. 
31 

The Board omitted the federal definition of"lndian country" from 40 C.F.R. 50.2(i), 

since no such area that falls within this definition exists in illinois. 

The Board omitted the definition of"Administrator," since the tenn "US EPA" is 

substituted for this term throughout the text of the rules. See 35 Ill. Adm. Code 243.102 

(defmition of"exceptional event"; corresponding with 40 C.F.R. 50.1(j)) and 243.102(b) 

(corresponding 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 

current 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.F.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 statement 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 110 

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)(II) 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.F .R. 58 sets forth the detailed requirements for air monitoring networks. As is 

discussed above, the Board has not included requirements from 40 C.F.R. 58 in this 

proceeding. The Board does not perceive those requirements to be part of the NAAQS, 

despite the important role the air monitoring 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 correlated 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 lll. 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 fmmer preamble 

statement, as described i1mnediately above. 

10 Part C of the Clean Air Act includes the federal PSD requirements. See 42 U.S.C. § 7470-92 

(2011). 
32 

Air Quality Monitoring 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 correspond 

with 40 C.F.R. 50.14 (2012) ("Treatment of air quality monitoring data influenced by 

exceptional events"). This provision sets forth the procedure for US EPA approval of 

excluding monitming data that resulted froin an exceptional event. Under the procedure, 

a state flags such data and requests that USEP A exclude that data. Upon an affnmative 

USEP A detennination that the data were the result of an exceptional event, USEP A will 

exclude that data from the detetmination of compliance. See 40 C.F.R. 50.14 (2012). 

The procedure also includes a requirement for public notification of an event that is 

expected to result in exceedance of any NAAQS. See 40 C.F.R. 50.14(c)(l) (2012). The 

term "exceptional event" is defmed in40 C.F.R. 50.l(j) as follows: 

(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 determined 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.l(j) (2012); see (35 Ill. Adm. Code 

243.101); see also 40 C.F.R. 50.1(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 Ill. Adm. 

Code 243.105(b)(1), (b)(2), and (b)(3). The Board further omitted expired federal provisions. 

See 35 Ill. Adm. Code 243.105(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 Ill. 

Adm. Code 243. Inclusion of the tabular matetial at corresponding with 35 Ill. Adm. Code 

243.105(c)(2)(F) would have required a two-inch left indent and extensive reorganization of the 

material. See 1 Ill. 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 conected the 

2010 one-hourNAAQS for nitrogen oxides from "80-100 PPB, final level TBD" to "100 ppb" 

11 Available online at www.cyberdriveillinois.com/publications. 
33 

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 Ill. 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 USEPA has established one or more 

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. USEPA 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 particulates in the ambient air. USEP A then used what has now been called 

"PM10," which are the patiiculates 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 "PM2.5," which is also called 

"fine patiiculates": those having an aerodynamic diameter of2.5 microns or less. See 40 C.F.R. 

50.7(a) (2012). The following table summarizes the development of the NAAQS for particulate 

matter (indicating currently codified standards in bold): 

1971 Primary Annual Average NAAQS for Total Suspended Particulates CTSP) 

(Removed) 

Standard: 

Citation: 

75 I-tglm3 annual geometric mean 

40 C.F.R. 50.6(a) (1986) (originally42 C.F.R. 410.6(a) (1971)) 

April30, 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 Primary 24-Hour NAAQS for Total Suspended Patiiculates (TSP) (Removed) 

Standard: 260 I-tg/m3 not to be exceeded more than once in a year 

12 This is an apparent error in fmal 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 20 I 0 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). 

13 USEPA adopted primary 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). 
34 

Citation: 40 C.F.R. 50.6(b) (1986) (originally 42 C.F.R. 410.6(b) (1971)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption. 

November 25, 1971 (36 Fed. Reg. 22384): Recodified without substantive 

reVlSlOn. 

July I, 1987 (52 Fed. Reg. 24634): Removed. 

1971 Secondary Annual Average NAAQS for Total Suspended Particulates (TSP) 

(Removed) 

Standard: 

Citation: 

60 ~g/m3 used for assessing implementation plans achieving the 1971 

secondary 24-hour standard 

40 C.F.R. 50.7(a) (1986) (originally 42 C.F.R. 410.7(a) (1971)) 

April30, 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 Secondary 24-Hour NAAQS for Total Suspended Particulates (TSP) (Removed) 

Standard: !50 ~g/m3 not to be exceeded more than once in a year 

Citation: 40 C.F.R. 50.7(b) (1986) (originally 42 C.F.R. 410.7(b) (1971)) 

April30, 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. 

1987 Primarv and Secondarv 24-Hour NAAQS for PM10 (Current) 

Standard: !50 ~g/m3 not to be exceeded more than once per year, on a three-year 

average basis 

Citation: 40 C.F.R. 50.6(a) (2012) 

July 1, 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 NAAQS for PM10 (Removed) 

Standard: 50 ~g/m3 annual arithmetic mean on a three-year average basis 

14 Not described in this summary outline because USEP A subsequently removed the sunset 

provision. See 40 C.F.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), aif'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). 
35 

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 Primary and Secondary Annual Average NAAOS for PM10 (Removed) 

Standard: 50 J.Lg/m3 annual arithmetic mean, averaged over three 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 Ptimary and Secondary 24-Hour NAAQS for PM10 (Removed) 

Standard: !50 j.Lg/m3 99th percentile, averaged over three 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 Primary and Secondarv Annual Average NAAQS for PM25 (Current) 

Standard: 15.0 J.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). 

1997 Primary and Secondarv 24-Hour NAAQS for PMz..2 (Current) 

Standard: 65 J.Lg/m3 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). 

2006 Primarv and Secondary Annual Average NAAQS for PM2.5 (Current) 

Standard: 15.0 J.Lgim3 atithmetic mean, averaged over three years 

Citation: 40 C.P.R. 50.13(a) (2012) 

October 17, 2006 (71 Fed. Reg. 61144): Original adoption. 

16 See supra note 14. 

17 See supra note 15. 
36 

2006 Primarv and Secondary 24-Hour NAAQS for PM, 5 (Current) 

Standard: 35 ~g/m3 98th percentile, averaged over three years 

Citation: 40 C.F.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 three 

federal rules: 40 C.F.R. 50.6, 50.7, and 50.13. There remains one standard for PM10 and four for 

PM2.5•

18 The Board has codified these five standards in 35 Ill. Adm. Code 243.120. The Board 

proposes replacing this particulate matter provision with the text of the five federal NAAQS. 

Each of the federal particulate 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 p1imary and secondary 24-hour NAAQS for PM10 

1997 primary and secondary annual average NAAQS for 

243.120(b) 40 c.F.R. 50.7 PMzs 

1997 p1imary 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 primary 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 incorporate them into the lllinois 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 

particulate matter. 

The Board has codified the federal NAAQS for pa1ticulate matter without substantive 

revision. All of the deviations from the literal text of the federal NAAQS are itemized in Table 

I. 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-attaimnent with the 

1987 standards once USEPA has established rules for non-attaimnent areas as required by 

18 USEPA proposed and declined to adopt a standard for coarse pmticulate matter (PM10.25). See 

the discussion that appears at page 20 of this opinion and order. 
37 

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 

USEP A 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, 175 F. 2d 1027, 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 p1imary 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.s because USEPA has done so. The 

2006 primary 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 primary and secondmy 24-hour NAAQS 

for PMz.s is more stringent than the 1997 24-hour standard. Compare 40 C.F.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 PM2.5 may have continuing 

vitality for implementation of various federal an1bient air quality rules. See 71 Fed. Reg. 61144, 

49 (Oct. 17, 2006). The explanation appended to the 1997 NAAQS for PM2.s outlines USEP A's 

addition of the 2006 annual average and 24-hour NAAQS for PM2.s and Board retention of the 

1997 standard. 

Section 243.122: Sulfur Oxides. USEPA has maintained prin1ary and secondary 

NAAQS for sulfur oxides since 1971. The following table summarizes the development of the 

NAAQS for sulfur oxides (indicating cunently codified standards in bold): 

1971 Primary Annual Average NAAQS for Sulfur Oxides (as S02) (Subject to 

Sunset) 

Standard: 

Citation: 

0.030 ppm annual arithmetic mean 

40 C.F.R. 50.4(a) (2012) (originally 42 C.F.R. 410.4(a) (1971)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 80 J.lg/m3 (O.Q3 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

reviSIOn. 

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 determining compliance. See 71 Fed. Reg. 61144, 77, 210-11 (Oct. 17, 2006). 
38 

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 USEP A designation of the 

attainment status of that area under the 2010 primary one-hour 

standard, with exceptions. 

1971 Primarv 24-Hour NAAQS for Sulfur Oxides (as S02) (Subject to Sunset) 

Standard: 0.14 ppm not to be exceeded more than once per year 

Citation: 40 C.P.R. 50.4(b) (2012) (otiginally42 C.P.R. 410.4(b) (1971)) 

April30, 1971 (36 Fed. Reg. 8186): Original adoption as 365 f.tg/m3 (0.14 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

reVISIOn. 

Apri121, 1993 (58 Fed. Reg. 21351): Retained without revision. 

May 22, 1996 (61 Fed. Reg. 25566): Immatetial change to 0.14 ppm (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 Secondary Annual Average NAAQS for Sulfur Oxides (as SO,) (Revoked) 

Standard: 60 [lglm3 (0.02 ppm) annual arithmetic mean 

Citation: 40 C.P.R. 50.5(a) (1972) (originally 42 C.P.R. 410.5(a) (1971)) 

Aptil30, 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 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.P.R. 410.5(b) (1971)) 

April 30, 1971 (36 Fed. Reg. 8186): Original adoption. 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

revts!On. 

September 14, 1973 (36 Fed. Reg. 25678): Revoked. 

1971 Secondary Three-Hour NAAQS for Sulfur Oxides (as S02) (Current) 

Standard: 0.5 ppm not to be exceeded more than once per year 

Citation: 40 C.P.R. 50.5 (2012) (originally42 C.P.R. 410.5(c) (1971), then40 

C.P.R. 50.5(c) (1972)) 
39 

April 30, 1971 (36 Fed. Reg. 8186): Original adoption as 1300 J.!g/m3 (0.5 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

revrswn. 

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 S02) (Current) 

Standard: 75 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 

federal rules: 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 proposes replacing 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)(l) 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 primary one-hour NAAQS for sulfur oxides 

As previously discussed, 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 vmious 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 

I. 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 mual average and 24-hour NAAQS 

for sulfur oxides with adoption of the 2010 primary NAAQS for sulfur oxides. 

Sunset Clause (or the 1971 Primary 24-Hour NAAQS (or Sulfur Oxides. Upon 

adoption of the 2010 primary one-hour NAAQS for sulfur oxides, USEPA added the following 

sunset clause: 
40 

The [ 1971 primaty 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 fmth 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 I 07 

of the Clean Air Act, for the [201 0] S02 NAAQS set fmth in§ 50.17; except that 

for areas designated nonattainment for the [ 1971 primary annual average and 24-

hour] S02 NAAQS set fmth 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 ptimary annual average and 24-hour] S02 NAAQS set fmth in this 

section, the [1971 prirnaty annual average and 24-hour] S02 NAAQS set fmth 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 attainment of the [2010] S02 NAAQS set fmth in§ 50.17. 40 C.F.R. 50.4(e) 

(2012); 75 Fed. Reg. 35520, 92 (June 22, 2010). 

The Board sees various alternatives for codifying this provision. One basic change would 

apply to all of the alternatives: 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 definitively 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-attainment as 

of August 23, 2010 (see 40 CFR 81.314 (20 I 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 primaty annual average and 24-hour] S02 NAAQS" as of that date (see 40 C.F.R. 52.720, 

52,722, and 52.724 (2012)). The Board was able to detetmine that USEPA had not made any 

attainment determinations 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 Chety! A. Newton, 

Director, Offtce of the Air and Radiation Division, USEPA 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 USEP A 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 

ftve options and selects one in the following paragraphs. 

Option 1: Retain the Entire Federal Text with Minimal Deviation. The ftrst option is 

for the Board to retain the entiTe text of 40 C.F.R. 50.4(e) with minimal deviation. ht addition to 
41 

the routine clarifying revisions, this alternative 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 explanatory 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 f01th 

in this subsection (a) remain applicable to all areas notwithstanding the 

promulgation of the 2010 p1imary one-hour NAAQS for sulfur oxides in 

subsection (c) of this Section. The 1971 plimary annual average and 24-hour 

NAAQS for sulfur oxides set f01th in this subsection (a) will no longer apply to an 

area one year after the effective date of the designation of that area by USEP A 

pursuant to 42 USC 7407 for the 2010 primary one-hour NAAQS for sulfur 

oxides set f01th in subsection (c) of this Section; except that the 1971 plimary 

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-hourNAAQS 

for sulfur oxides set f01th 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 f01th 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 ptimmy annual average and 24-hour NAAQS 

for sulfur oxides set f01th in this subsection (a). 

BOARD NOTE: The Board substituted "August 23, 2010" for the open-ended 

language in conesponding 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 primary one-hour NAAQS for sulfur 

oxides. See letter of June 2, 20 II 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 
42 

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 fll"St 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 20 I 0 primmy 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 f01th in 

this subsection (a) after fulfillment of the conditions recited by USEPA in 

CO!Tesponding 40 CFR 50.4(e) pursuant to 42 USC 7407 for the 2010 

primmy one-hour NAAQS for sulfur oxides set forth in subsection (c) of 

this Section; except that the 1971 p1imary 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 p1imary one-hour NAAQS for sulfur 

oxides set forth in subsection (c) of this Section. 

Option 3: Replace tlze Statement o(lnapplicabilitv witlz a Statement That tlze Board 

Will Remove tlze 1971 NAAOS Wizen 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 

primary 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-hourNAAQS for sulfur oxides 

set forth in this subsection (a) remains applicable to all areas 

notwithstanding the promulgation of the 20 I 0 primmy one-hour NAAQS 

for sulfur oxides in subsection (c) of this Section. The Board will delete 

the 1971 p1imary annual average and 24-hour NAAQS for sulfur oxides 

set forth in this subsection (a) after fulfillment of the conditions recited by 

USEPA in corresponding 40 CFR 50.4(e). 

BOARD NOTE: Conesponding 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 20 I 0 primary one-hour 

NAAQS for the 1971 primary NAAQS 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 of that date, USEPA had not designated 

any area in Illinois as non-attainment. See 40 CFR 81.314 (20 10). The 

Board is unaware of any USEPA SIP call for any area of Illinois relative 
43 

to the 1971 primary NAAQS for sulfur oxides. As of December 31, 2012, 

USEPA had not yet designated the attaimnent 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 2010 primary 

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, USEPA 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 USEPA has removed 40 CFR 50.4, the Board 

will remove the standard of this subsection (a) as obsolete. 

Option 4: Replace tlte Statement o(Inapplicabilitv with a Statement Tfzat tfze Board 

Will Remove tfze 1971 NAAOS Wizen USEPA Makes Area Designations Under tlte 2010 One 

Hour NAAOS or Removes the 1971 NAAOS. The fourth option is a variation of the third 

option. This fourth option is for the Board to replace the text of40 C.F.R. 50.4(e) with a 

statement that Board will remove the 1971 primary annual average and 24-hourNAAQS 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 primary annual average and 24-hour NAAQS for sulfur oxides 

set forth in this subsection (a) remain applicable to all areas 

notwithstanding the promulgation of the 20 I 0 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 forth in this subsection (a) after USEPA has made attaimnent 

designations with regard to all areas in Illinois under the 20 I 0 primmy 

one-hour NAAQS for sulfur oxides or USEPA has removed the existing 

standard of 40 CFR 50.4. 

Option 5: Remove tfze 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 TIL 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 p1ima1y annual average and 24-

hour NAAQS from the Illinois regulations. 

Selection of Option 3. The Board proposes 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 prima1y NAAQS after fulfilhnent of the federal conditions. Option 3 

preserves the statement of applicability. Option 3 is consistent with the Board's identical-in-
44 

substance rulemaking 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 dete1mined between USEPA and the Agency. 

The Board requests that the Agency inform the Board in the future should USEPA 

determine that the 1971 primaryNAAQS for sulfur oxides do not apply to any area of Illinois. 

The Board can list areas of inapplicability in future updates to the NAAQS and ultimately 

remove 35 Ill. 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 197.1. 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 NAAgs for Carbon Monoxide (Current) 

Standard: 9 ppm (I 0 mg/m) not to be exceeded more than once per year 

Citation: 40 C.F.R. 50.8(a)(l) (2012) (originally 42 C.F.R. 410.8(a) (1971), then 

40 C.F.R. 50.8(a) (1972)) 

Apri130, 1971 (36 Fed. Reg. 8186): Original adoption as 10 mg/m3 (9 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

reVJSIOll. 

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 

Jlg/m3

), renumbered to subsection (a)(!). 

August 1, 1994 (59 Fed. Reg. 38906): Retained without revision. 

August 31,2011 (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.F.R. 50.8(a) (1985) (originally 42 C.F.R. 410.8(a) (1971)) 

April30, 1971 (36 Fed. Reg. 8186): 01iginal 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 Primary 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.F.R. 50.8(a)(2) (2012) (originally 42 C.F.R. 410.8(b) (1971), then 

40 C.F.R. 50.8(b) (1972)) 
45 

April30, 1971 (36 Fed. Reg. 8186): Oliginal adoption as 10 mg/m3 (9 ppm). 

November 25, 1971 (36 Fed. Reg. 22369, 84): Recodified without substantive 

revlSlon. 

Febmary 18, 1975 (40 Fed. Reg. 7042): Amended to require the use of federally 

approved monitoling methods (FRMs and FEMs). 

September 13, 1985 (50 Fed. Reg. 37484): Immaterial change to 9 ppm (10 

11g/m3), renumbered to subsection (a)(2). 

August 1, 1994 (59 Fed. Reg. 38906): Retained without revision. 

August 31, 2011 (76 Fed. Reg. 54294): Retained without revision. 

1971 Secondary One-Hour NAAOS for Carbon Monoxide (Revoked) 

Standard: 35 ppm ( 40 mg/m3

) not to be exceeded more than once per year 

Citation: 40 C.P.R. 50.8(b) (2012) (originally42 C.P.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, 84): Recodified without substantive 

revision. 

Febmary 18, 1975 (40 Fed. Reg. 7042): Amended to require the use offederally 

approved monitoring methods (FRMs and FEMs). 

September 13, 1985 (50 Fed. Reg. 37484): Revoked. 

Two plima1y NAAQS for carbon monoxide remain codified in one federal regulation: 40 

C.P.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 proposes to replace 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 mles. The 

two NAAQS are codified as follows: 

Subsection Federal Citation 

243.123(a)(l) 40 C.P.R. 50.8(a)(l) 

243.123(b)(2) 40 C.P.R. 50.8(a)(2) 

NAAQS 

1971 primary eight-hour NAAQS for carbon 

monoxide 

1971 primary one-hour NAAQS 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 USEPA has adopted, reviewed, and amended the vmious 

standards. Those notices m·e listed in the foregoing review of the federal standards for carbon 

monoxide in the initial portion of this discussion. 
46 

The Board has codified the federal NAAQS for carbon monoxide without substantive 

revJsJOn. All of the deviations from the literal text of the federal NAAQS are itemized in Table 

I. 

Section 243.124: Nitrogen Oxides. USEPA adopted p1imary 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 curr-ently codified 

in bold): 

1971 Primarv Annual Average NAARS for Nitrogen Oxides (as N07) (Current) 

Standard: 0.053 ppm (1 00 Jlg/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 Jlg/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 primary NAAQS and 

renumbered subsection (a) with immate1ial change to 0.053 ppm 

(1 00 Jlglm3

) (significant digit added, metric and non-metric units 

switched). 

October 8, 1996 (61 Fed. Reg. 52852): Retained without revision. 

February 9, 2010 (75 Fed. Reg. 6474): Retained with inunaterial change to 53 

ppb (units changed, metric units removed). 

1971 Secondarv Annual Average NAAOS for Nitrogen Oxides (as NO,) (Current) 

Standard: 0.053 ppm (1 00 Jlg/m3) annual arithmetic mean 

Citation: 40 C.F.R. 50.1l(c) (2012) (originally 42 C.F.R. 410.11 (1971), then 40 

C.F.R. 50.11 (1972) and 40 C.F.R. 50.1l(b) (1985)) 

April 30, 1971 (36 Fed. Reg. 8186): Original adoption as a primary and 

secondary NAAQS of I 00 Jlg/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 Jlg/m3

) (significant digit added, metric and non-metric 

units switched). 

October 8, 1996 (61 Fed. Reg. 52852): Retained without revision. 

February 9, 2010 (75 Fed. Reg. 64 74): Retained without revision; renumbered 

subsection (c). 

2010 Primary One-Hour NAAOS 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.F.R. 50.ll(b) (2012) 
47 

Febmary 9, 2010 (75 Fed. Reg. 6474): Original adoption. 

Two ptimary and one secondary NAAQS for nitrogen oxides are codified in one federal 

mle: 40 C.F.R. 50.11. The Board has codified the two 1971 standards in 35 Ill. Adm. Code 

243.124. The Board proposes to replace 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 

243.124(a) 40 C.F.R. 50.ll(a) 

243.124(b) 40 C.F.R. 50.1l(b) 

243.124(c) 40 C.F.R. 50.5 

NAAQS 

1971 primary ammal average NAAQS for nitrogen oxides 

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 portion of this discussion. 

The Board has codified the federal NAAQS for nitrogen oxides without substantive 

revisiOn. All of the deviations fiom the literal text of the federal NAAQS are itemized in Table 

1. 

Section 243.125: Ozone. USEPA adopted the initial primmy and secondary one-hour 

NAAQS for photochemical oxidants21 in 1971. USEPA superseded that primary and secondary 

one-hour standard in 1979 with a standard for ozone. USEPA 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: 

21 Photochemical oxidants are pollutants formed in the atmosphere by the reaction of nitrogen 

oxides with hydrocarbons. USEP A, Communications, Education, and Public Affairs, Terms of 

Environment: Glossary, Abbreviations, and Acronym (Dec. 1997), EPA 17 5-B-97 -001, at 35. 

Ozone is the principal photochemical oxidant. Others are nitrogen dioxide, peroxyacetyl 

nitrates, fmmaldehyde, acrolein, and organic peroxides. See Proposed Air Qualitv Standards, 

R72-7 (July 10, 1975), slip op. at23-24. 
48 

1971 Primary and Secondary One-Hour NAAQS for Total Photochemical Oxidants (0J0_ 

(Removed) 

Standard: 0.08 ppm not to be exceeded more than one hour per year 

Citation: 40 C.F.R. 50.9 (1972) (originally 42 C.F.R. 410.9 (1971)) 

Ap1il 30, 1971 (36 Fed. Reg. 8186): Original adoption as 160 11g/m3 (0.08 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). 

February 8, 1979 (44 Fed. Reg. 8202): Removed 

1979 Primarv and Secondarv One-Hour NAAQS for Ozone (03) (Subject to Sunset) 

Standard: 0.12 ppm not to be exceeded more than one day per year 

Citation: 40 C.F.R. 50.9(a) (2012) 

February 8, 1979 (44 Fed. Reg. 8202): Original adoption as 0.12 ppm (235 

fLg/m3). 

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 2008 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 

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. 

22 As 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 determination 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 determination 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 determination of inapplicability). 
49 

May 21,2012 (77 Fed. Reg. 30160, 70): Partial sunset provision added: 23 the 

1997 primary and secondary eight-hour standard will no longer 

apply to an area for transportation conformity purposes only one 

year after USEP A has made a designation of the area for the 2008 

primary and secondary eight-hour standard. 

2008 Primary and Secondary 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. 

Tlu·ee primaty and secondary NAAQS for ozone are codified in tlu·ee federal rules: 40 

C.F.R. 50.9, 50.10, and 50.15. The Board has codified the 2008 ptimary and secondaty eighthour NAAQS for ozone in 35 Ill. Adm. Code 243.125. The Board proposes to replace the 

existing provision relative to ozone with the text of the federal NAAQS, adding the still-federally 

codified 1979 primary and secondary one-hour NAAQS and the 1997 primary and secondary 

eight-hour NAAQS to the text. Each of the federal provisions relative to ozone appears in a 

separate subsection, with the subsection for each of the standards. The three NAAQS for ozone 

are codified as follows: 

Subsection Federal Citation NAAQS 

243.125(a) 40 C.F.R. 50.9 1979 Primary and Secondary One-Hour NAAQS for Ozone 

243.125(b) 40 C.F.R. 50.10 1997 Primary and Secondary Eight-Hour NAAQS for Ozone 

243.125(c) 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 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 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 1. 

23 The 1997 primary and secondary eight-hour standard continues to apply for all other purposes. 

See 40 C.F.R. 50.10(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 

while USEPA fmmulates rules for transition fi·om the 1997 standard to the 2008 standard. See 

73 Fed. Reg. 16436, 503 (Mar. 27, 2008). 
50 

Two revisions that the Board has not made warrant discussion. These relate to the continued 

viability of the 1979 one-hour and 1997 eight-hour NAAQS for ozone. 

Sunset ofthe 1979 Primmy and Secondmy One-Hour NAAOS for Ozone. The 

conditions of the sunset clause applicable to the 1979 one-hour standard will be fulfilled before 

fmal adoption of the present amendments. It may be possible for the Board to omit the material 

derived from 40 C.F.R. 50.9 from the adopted version of the present amendments. 

US EPA revoked the 1979 one-hour NAAQS 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). The federal SIP requirements 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 2008 eighthour standard. 40 C.F.R. 51.905(e) (2012). Eight years after that revocation is June 15,2013. 

· The 1979 standard provides that it no longer applies to an area one year after the effective 

date of its area designation by US EPA for the 2008 primary and secondary eight-hour standard 

for ozone. See 40 C.F.R. 50.9(b) (2012). USEPA designated areas of Illinois for the 2008 

primary and secondary eight-hour NAAQS for ozone effective July 20, 2012. See 40 C.F.R. 

81.314 (2012) (the table for the 2008 eight-hour NAAQS for ozone); 77 Fed. Reg. 34221 (June 

11, 2012) (designation of areas surrounding Chicago); 77 Fed. Reg. 30088 (May 21, 2012) 

(designation of the rest of Illinois). 

Thus, it appears that the 1979 one-hour NAAQS for ozone will not apply to any area of 

Illinois after July 20, 2013. It also appears that the State may apply to USEPA to remove the 

requirement for a maintenance plan for the 1979 one-hour standard after June 15,2013. The 

Board has included the 1979 one-hour NAAQS in this proposal for public comment, but it is 

possible that the Board may remove the standard from the final version of these mles. 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 o(the 1997 Prim my and Secondmy Eight-Hour NAAOS tor 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 partial-for purposes 

of transportation conf01mity alone. The partial 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 

11, 2012) (designation of areas sun·ounding Chicago); 77 Fed. Reg. 30088 (May 21, 2012) 

(designation of the rest of Illinois). The Board proposes including 40 C.F.R. 50.10 in the present 

amendments due to the patiial nature of the sunset provision. 

Section 243.126: Lead. USEPA adopted the initial primaryNAAQS 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 plimary NAAQS for lead are outlined as follows: 
51 

1978 Primarv Calendar puarterlv Average NAAQS for Lead (Subject to Sunset) 

Standard: 1.5 f!g/m maximum mithmetic mean averaged over a calendar quarter 

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. 

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 primary and secondary tlu·ee-month average standard, . h . '4 w1t one exceptwn- . 

2008 Primarv Three-Month Average NAAQS for Lead (Current) 

Standard: 0.15 f1g/m3 arithmetic mean averaged over a tlu·ee-month period 

Citation: 40 C.F.R. 50.16(a) (2012) 

November. 12, 2008 (73 Fed. Reg. 66964): Original adoption. 

Both primary NAAQS for lead remain codified in two federalmles: 40 C.F.R. 50.12 and 

50.16. The Board has codified the 2008 primary three-month NAAQS for lead in 35 Ill. Adm. 

Code 243.126. The Board proposes to replace the existing provision relative to lead with the text 

of the federal NAAQS, adding the 1978 p1ima1y calendar quarterly NAAQS for lead to the text. 

Each of the federal provisions relative to lead appears in a separate subsection, one for each of 

the I 978 and 2008 standards. The two NAAQS for lead are codified as follows: 

Subsection Federal Citation NAAQS 

243.126(a) 40 C.F.R. 50.12 1978 Primary Calendar Quarterly Average NAAQS for Lead 

243.126(b) 40 C.F.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 

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 US EPA 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 I. The Board 

24 The exception relates to areas deemed not in attainment with the 1978 standard before the 

effective date of the 2008 standard. 
52 

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 ofthe 1978 Primmy Calendar Ouarterlv Average NAAOS tor 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 proposal. 

When adopting the 2008 standard, USEP A added a sunset clause to the 1978 primary 

calendar quarterly average NAAQS for lead. See 40 C.F.R. 50.12(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 USEP A has designated "non-attainment" with the 2008 

standard. See 40 C.F.R. 50.12(b) (2012). For non-attainment areas, the 1978 standard no longer 

applies after USEPA has approved a plan for attainment or maintenance of the 2008 NAAQS. 

Seeld. 

For the 2008 NAAQS for lead, USEPA has designated two areas of the state as nonattainment and the rest of the State as "unclassifiable/attainment." The two non-attainment 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 USEP A actions in the several identical-in-substance subject areas25 

on an ongoing basis for USEP A actions that would require Board rulemaking activity. If the 

Board observes a USEPA action subsequent to the nominal timeframe 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., SDWA Update. USEPA Amendments 

(January I. 2012 through June 30.2012. and July 25. 2012), Rl3-2 (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), R09-16, RCRA Subtitle C Update. USEPA 

Regulations (January I. 2009 through June 30. 2009), Rl0-4 (June 17, 2010), slip op. at 5-6,272 

(withdrawing amendments); SDWA Update. USEP A Amendments (January I. 2007 though June 

30. 2007 and June 3. 2008), R08-7, SDW A Update. USEP A Amendments (July I. 2007 though 

December 31. 2007). R08-13 (Dec. 18, 2008), slip op. at 4, 8 (adding amendments). 

25 Defmition of volatile organic material, 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). 
53 

On January 15,2013, USEPA detetmined to retain the 1987 primary and secondary 24-

hour NAAQS for PM10, revised the data handling conventions applicable to all four of the PM2.5 

NAAQS26, and adopted two new NAAQS for patticulate matter27 There are one new NAAQS 

for PM10 and three new NAAQS for PM2.5. Those standards are the following (using the format 

employed above for all of the historical and existing NAAQS): 

1987 Primary and Secondary 24-Hour NAAQS for PM10 

Standard: !50 [.tg/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. 28 

December 22, 2000 (65 Fed. Reg. 80776): Sunset provision removed29 

January 15,2012 (78 Fed. Reg. 3086): Retained without revision. 

1997 Primary and Secondary Annual Average NAAQS for PM2 5 

Standard: 15.0 [.tg/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). 

January 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 Primary and Secondary 24-Hour NAAQS for PM,.s 

Standard: 65 [.tg/m3 98th percentile, averaged over three years 

Citation: 40 C.P.R. 50.7(a) (2012) (miginally 40 C.P.R. 50.7(a)(l) (1998)) 

26 The 1997 and 2006 Primary and secondary annual average and 24-hour NAAQS for PM2.5• 

27 The USEPA NAAQS webpage (www.epa.gov/ttn/naaqs/standards/pm/s_pm_histmy.html) 

lists all of the remaining standards as 2012 standards: the primary annual NAAQS for PM2.5, 

added as 40 C.P.R. 50.!8(a); the secondaty annual NAAQS for PM2.5, which remains unchanged 

as 40 C.P.R. 50.13(a) (the 2006 standard); the primaty 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 primm·y and secondary 24-hour NAAQS for PM10, which remains 

codified as 40 C.P.R. 50.6(a) (the 1987 standard). 

28 Not described in this summaty outline because USEP A subsequently removed the sunset 

provision. See 40 C.P.R. 50.6(d) (1998) (the removed sunset provision). 

29 As a result of the decision in American Tmcking 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 

Tmcking 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). 
54 

July 18, 1997 (62 Fed. Reg. 38652): Original adoption. 

July 30, 2004 (69 Fed. Reg. 45592): Renumbered to subsection (a). 

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 Secondary Annual Average NAAQS for PM2.s 

Standard: 15.0 f.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 PMz 5 

Standard: 35 f.lg/m3 98th percentile, averaged over three years 

Citation: 40 C.F.R. 50.13(a) (2012) 

October 17, 2006 (71 Fed. Reg. 61144): Original adoption. 

Janumy 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 PM, 5 

Standard: 12.0 f.Lg/m3 arithmetic mean, averaged over tlu·ee 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 f.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 

PM2.

5 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 Janumy 13,2013 federal amendments in this proceeding or in a 

separate proceeding that could conclude as late as January 14,2014. 30 

30 See 415 ILCS 5/7.2(b) (2012). 
55 

Requests for Public Comments 

The Board requests comments on general aspects of the 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 requests public comments on specific aspects of the 

proposal. The specific requests for comments are itemized as follows: 

1. 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 is subject to USEPA review and approval? Is there any reason the 

Illinois NAAQS regulations should include incmporation of 40 C.F.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 perfmmed to fulfill the requiTements of this Part must be 

performed 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. 

2. Removal of non-degradation requirement: Do the federal PSD requiTements 

render the non-degradationmle of35 Ill. Adm. Code 243.104 unnecessary? Is 

there any way that the Board should perceive non-degr·adation as a segment of the 

federal NAAQS? 

3. USEPA approvals ofFRMs and FEMs: Will the unavoidable delay in 

incmporation ofUSEP A methods designations into the illinois regulations create 

difficulty in implementation of the federal NAAQS in Illinois? Is there any 

available alternative that could minimize the delay? 

4. Expiration of the 1979 one-hour NAAOS for ozone: Is it true 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 standard for ozone after that date? 

5. Expiration of the requirement for a maintenance plan for the 1979 one-hour 

NAAQS for ozone: Is it tme that the State may apply to USEPA 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 US EPA approval? 

6. Partial expiration of the 1997 prinrary and secondary eight-hourNAAQS for 

ozone: Is it hue that that the 1997 eight-hour standard for ozone will no longer 

apply to any aTea after June 15, 2013 for transportation conformity purposes? For 

what purposes will that 1997 standard continue to apply? What event or series of 
56 

events could occur within the next few years that could warrant removal of the 

1997 from the Illinois regulations? 

7. Expiration of the 1978 primary calendar quarterly average NAAQS for lead: Is it 

true that the 2011 and 2012 area designations for the 2008 NAAQS for lead 

rendered the 1978 calendar quarterly NAAQS for lead inapplicable to all areas of 

Illinois except for the two limited non-attainment areas? What is the current 

status of the State obtaining an approved attaimnent 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 from the Illinois 

regulations? 

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 alternative, 

should the Board wait until USEPA has expressly codified that the NAAQS does 

not apply to any area in Illinois? As a second alternative, should the Board leave 

that NAAQS in the Illinois rules until USEPA has removed that standard from 40 

C.F.R. 50? 

Deviations from the Literal Text of the Federal Amendments 

and Non-Federally 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 correction or clarification. JCAR and the Office of the 

Secretary of State also routinely examine the text and suggest corrections and clarifications. 

Sometimes suggestions arise from the Agency, USEP A, or members of the regulated 

community. The Board often makes revisions as a result. The revisions thus made ar·e not 

directly derived 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 lllinois 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 corrections are non-substantive in effect. Tables follow that document the 

corrections and clarifications made in this proceeding. The first lists the deviation from the 

literal text of the USEP A amendments involved in this proceeding. The second lists the 

correction made in this docket that was not prompted by federal amendments. 

Tabulations of Deviations from the Literal Text of the Federal Amendments and 

Miscellaneous Board Housekeeping Amendments. 

The tables below list numerous corrections and amendments that are not based on current 

federal amendments. Table 1 (beginning immediately below) lists a number offederal 

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 (begilliling innnediately below) includes 
57 

deviations made in this proposal for public comment from the verbatim text of the federal 

amendments. Table 2 (beginning immediately after Table 1 on page 91) contains corrections and 

clarifications that the Board made in the base text involved in this proposal. The amendments 

listed in Table 2 are not directly detived from the current federal amendments. Some of the 

entties in these tables are discussed fmther in appropriate segments of the general discussion 

beginning at page 8 of this opinion. 

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 I to 50.14(c)(2)(vi) Removed "Data to be Used for 

243.105 heading heading Designations Decisions" from before 

"for New or Revised NAAQS"; changed 

the fmmat from large and small capital 

letters to standard fmmat with 

capitalization of the first letter of each 

word in the heading. 

243.101 generally 40 C.P.R. 50.1 Replaced the existing language with new 

language more directly derived from the 

corresponding federal provision. 

243.101 preamble 40 C.P.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.P.R. 50.l(b) Placed the defmed tenn in quotation 

marks; changed the defmition fiom 

meaning the federal CAA, as amended, 

to mean the Environmental Protection 

Act. 
58 

243.101 "Agency" 40 C.F.R. 50.l(c) Placed the defined te1m in quotation 

marks; changed the definition from 

meaning USEP A, as amended, to mean 

the Illinois EPA. 

243.101 "Clean Air 40 C.F.R. 50.1(b) Created the separate defined te1m to 

Act" mean the federal statute; placed the 

defined te1m in quotation marks; added 

the alternative defined abbreviated term 

"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 defmed te1m in quotation 

of an NAAQS" marks; moved the defmition into 

alphabetic order; changed the long 

defined term "exceedance with respect 

to a national ambient air quality 

standard" to the shorter fonn 

"exceedance of an NAAQS." 

243.101 "exceptional 40 C.F.R. 50.1G) Placed the defmed te1m in quotation 

event" marks; moved the defmition into 

alphabetic order; added "fulfills all of 

the following crite1ia" and a colon after 

"that"; divided so to place each criterion 

into a separate subsidiary paragraph; 

added "the event" (four times); changed 

the connnas to semicolons to separate 

each criterion; changed "Administrator" 

to "USEP A"; changed "it does not" to 

"an 'exceptional event' does not"; added 

"any of the following," followed by a 

colon, and subdivided the conditions 

into subsidiary paragraphs; changed the 

separating commas to semicolons. 
59 

243.101 "federal 40 C.P.R. 50.l(g), Placed the defmed te1m in quotation 

equivalent method" 50.1l(d)(2), and 53.1 marks; moved the definition into 

alphabetic order; added "federal" to the 

defined te1m and the abbreviated 

alternative definition "PEM" based on 

the definition 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 part 53 of this 

chapter" to "pursuant to 40 CPR 53 and 

which is listed included in List of 

Designated Methods, including later 

updates, as incorporated by reference ... 

243.108"; changed "it does not include" 

to "the te1m 'federal equivalent method' 

does not include"; changed "for which 

an equivalent method designation has 

been cancelled" to active-voice "for 

which USEPA 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.l(g), Added explanation of the derivation of 

equivalent method" 50.ll(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. 
60 

243.101 "federal 40 C.F.R. 50.l(f) and Placed the defmed term in quotation 

reference method" 53.1 marks; moved the definition into 

alphabetic order; added "federal" to the 

defined term and the abbreviated 

altemative definition "FRM" based on 

the definition that appears at closely 

related 40 C.F.R. 53.1; changed "that 

has been designated" to active-voice 

"that USEPA has designated" (twice); 

changed "in an appendix to this pmi" to 

"in an appendix to 40 CFR 50, 

incorporated ... 243.108"; changed "in 

accordance with pmi 53 of this chapter" 

to "pursuant to 40 CFR 53 and which is 

listed included in List of Designated 

Methods, including later updates, as 

incorporated by reference ... 243.108"; 

changed "it does not include" to "the 

tem1 '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 CFR 53.11 or 53.16"; added the 

parenthetical "as reflected in ... Section 

243.108." 

243.101 "federal 40 C.F.R. 50.l(f) a11d Added explanation of the derivation of 

reference method" 53.1 the defmition from multiple sources; 

Board note added expla11ation of "including later 

updates"; added explanation of the 

effectiveness of designation of an FRM 

a11d cancellation of an FRM. 

243.101 "micrograms 40 C.F.R. 50.6(a); Added the definition of the term and the 

per cubic meter" 50.7(a), and 50.13(a) and abbreviated form to suppmi consistent 

58.1 (definitions of use of the abbreviated form throughout 

PM2.s, PMw, PM we, and the text. 

PM10-2.s) 
61 

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." 

PM2.5, PM10, PM10c, and 

PM10-2.s) 

243.101 "milligrams 40 C.F.R. 50.8(a)(l) and Added the defmition of the term and the 

per cubic meter" (a)(2) abbreviated form to support consistent 

use of the abbreviated form throughout 

the text. 

243.101 "National 40 C.F.R. 50 generally, Borrowed the definition of the term and 

Ambient Air Quality and "Tetms of the abbreviated fonn to support 

Standards" Enviromnent: Glossaty, consistent use of the abbreviated form 

Abbreviations, and throughout 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.!01 "National 40 C.F.R. 50 generally, Added explanation of the added 

Ambient Air Quality and "Tetms of definition and its source. 

Standards" Board note Environment: Glossary, 

Abbreviations, and 

Acronyms" (Dec. 1997) 

243.101 "natural 40 C.F.R. 50.1(±) and Placed the defmed tetm 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 "Tetms of abbreviated form to support consistent 

Enviromnent: Glossary, use of the abbreviated form throughout 

Abbreviations, and the text. 

Acronyms" (Dec. 1997) 

243.101 "pru1s per 40 C.F.R. 50 generally, Added explanation of the added 

billion" Board note and "Terms of definition and the definition of"parts per 

Enviromnent: Glossary, million" and their source. 

Abbreviations, and 

Acronyms" (Dec. 1997) 
62 

243.101 "parts per 40 C.F .R. 50 generally, Derived the defmition and the 

million" and "Terms of abbreviated form to suppmt consistent 

Environment: Glossaty, use of the abbreviated form throughout 

Abbreviations, and the text. 

Acronyms" (Dec. 1997) 

243.101 "PMw" 40 C.F.R. 50.6(c) De1ived the definition of the abbreviated 

parenthetical form to support consistent use of the 

abbreviated fonn throughout the text; 

placed the defined te1m in quotation 

marks; changed "pmticles having" to 

"particulate matter that has"; added the 

abbreviation "f.!m" in parentheses. 

243.101 "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 defmition of the abbreviated 

parenthetical form to support consistent use of the 

abbreviated form thmughout the text; 

placed the defined te1m in quotation 

marks; changed "pmticles having" to 

"pmticulate matter that has"; added the 

abbreviation "f.!m" 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 defmed te1m in quotation 

marks; moved the defmition into 

alphabetic order; added the comma 

before "such as a National Bureau of 

Standards ... reference Manual (CRM)" 

to offset the parenthetical. 

243.101 "USEPA" 40 C.F.R. 50.l(c) Added the defmition based on the 

federal definition of"Agency"; changed 

the defined term to "USEP A"; added 

"United States" before "Environmental 

Protection Agency." 

243.101 "USEPA" 40 C.F.R. 50.1(c) Added explanation of the derivation and 

Board note use of the defmed term in the text. 

243.101 Board note 40 C.F.R. 50.1 generally Added explanation of the derivation of 

this Section. 
63 

243.102 heading 50.2 heading Changed the heading from "Preamble" 

to "Scope" to cotTespond with the 

federal regulations. 

243.102 generally 50.2 generally Replaced the existing language of this 

Section with that of the corresponding 

federal regulation. 

243.102(a) 50.2(a) Changed "as set forth in this part" to 

"This Part sets forth" 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 I 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 IO(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 "primaty and secondary 

standards" to "primary 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 counhy" to 

"this State." 

243.102 Board note 40 C.F.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 counterpart. 

243.105 generally 50.14 generally Added the provision relative to 

monitoring data and exceptional events 

that had not counterpart in the Illinois 

regulations. 
64 

243.105 heading 50.14 heading Removed "Treatment of' fi·om before 

"air quality monitoring data"; capitalized 

the first letter of each word in the 

heading. 

243.105(a)(l) 50.14(a)(l) Changed Ha State" to "the Agency"; 

change "EPA" to "USEP A"; moved 

"from use in the detetminations" 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 USEP A." 

243.105(a)(2) 50.14(a)(2) Added the indefmite article 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 )(1) 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 othetwise satisfies" to 

"and the Agency othetwise satisfies"; 

changed "this section" to "40 CFR 

50.14." 
65 

243.105(b)(2) 50.14(b)(2) Added the topical heading "Fireworks 

displays."; changed "EPA" to 

"USEP A"; 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"; added 

"USEP A has stated that" before "such 

data"; changed "a State demonstrates" to 

"the Agency has demonstrated"; 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 "USEPA" 

(three times); added "has stated that it 

will"; changed "exceedances or NAAQS 

violations" to the singular defmed 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 othetwise 

satisfies" to "and the Agency othetwise 

satisfies"; changed "this section" to "40 

CFR 50.14"; changed "definition in 

§ 50.1U)" to "definition of"exceptional 

event in Section 243.101"; changed 

"State" to "Agency''; changed "it" 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." 
66 

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 occuJTences in this 

subsection; added explanation of 

reliance on the defined te1m 

"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)(l),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 

"exceedance of an applicable air quality 

standard" to the defined term to 

"exceedance 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 term 

"exceedance of an NAAQS"; changed 

"EPA notifies the State" to "after 

USEP A notifies the Agency" and moved 

it from before "by placing as 

concun·ence flag" to follow "until"; 

changed "of its concuJTence following 

the State's" to "ofUSEPA concunence 

following the Agency's"; changed "its 

demonstration" to "a demonstration." 

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 "USEP A." 
67 

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 USEPA"; changed "its" 

to "USEP A"; added the conuna before 

"and providing" to offset the final 

element of a series; changed "Table 1 

provides the schedule" to "Table A to 

this Part 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 "USEPA 

has stated that it will revise the table 

upon which Table A to this Pmt 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 USEPA" 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." 

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. 
68 

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.P.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 derivation of 

this Section. 

243.108 50.4(c); 50.5(b); 50.6(a), Added this provision for inclusion of 

(c)(l), and (c)(2); required methods and intetpretations by 

50.7(b)(l) and (b)(2); incorporation by reference to the 

50.8(b )(1) and (b )(2); appendices to 40 C.P.R. 50 and the List 

50.9(a); 50.10(a) and (b); of Designated Methods. 

50.ll(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, P, G, H, I, J, K, L, 

M,N,O,P, Q,R, S, S, 

and T to 40 C.P.R. 50 

generally 
69 

243.120 50.6, 50.7, and 50.13 Replaced the existing language of this 

generally Section with that of the corresponding 

federal regulations. 

243.120(a) 50.6 heading Changed "national primaty 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 primaty and 

secondary 24-hour ambient air quality 

standards for particulate matter" to 

"1987 primary and secondary 24-hour 

NAAQS for PM10"; changed 

"micrograms per cubic meter (/-Lg/m3

)" 

to the defined term "!-Lg/m3"; changed 

"standards are" to "1987 primary and 

secondary 24-houor NAAQS for PM10 

is"; changed "this part" 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 

corresponding federal rule. 

243.120(a)(3) 50.6(c) Changed "primary and secondary 

standards" to "1987 primary and 

secondary 24-hour NAAQS for PM10"; 

changed "shall" to "must"; removed the 

parenthetical "(particles with an 

aerodynamic diameter 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." 
70 

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 "byUSEPA and listed 

in" after "and designated"; changed "in 

accordance with part 53 of this chapter" 

to "in List of Designated Methods, 

incorporated by reference in Section 

243.108." 

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 part 53 of this chapter" to "in 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 oflitigation. 

243.120(b) 50.7 heading Changed "national primmy and 

secondary ambient air quality standards 

for PM2_5" to "1997 primary and 

secondary atmual average and 24-hour 

NAAQS for PM2.s-" 
71 

243.120(b)(l) 50.7(a) Changed "the national primary and 

secondary 24-hour ambient air quality 

standards for particulate matter are ... 

annual arithmetic mean concentration, 

and ... 24-hour average concentration" 

to "1997 prima1y and secondary annual 

average NAAQS for PM10 is ... , annual 

arithmetic mean concentration, and ... , 

24-hour average concentration,"; 

changed "micrograms per cubic meter 

(f.Lg/m3)" to the defined te1m "fLg/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"PM2.5" 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(b )(1 )(A) 50.7(a)(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 pmt 53 of this chapter" 

to "in 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 part 53 of this chapter" to "in List 

of Designated Methods, incorporated by 

reference in Section 243.1 08." 
72 

243.120(b)(2) 50.7(b) Changed "annual primary and secondary 

PM2.s 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 term "f!g/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_5 is"; changed 

"this part" to "40 CFR 50, incorporated 

by reference ... Section 243.108"; 

changed "micrograms per cubic meter" 

to the defined term "f!g/m3

." 

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.s and Board retention 

of the 1997 NAAQS for PM2.5. 

243.120(c) 50.13 heading Changed "national primary and 

secondary ambient air quality standards 

for PM2.s" to singular "2006 primary and 

secondary annual average and 24-hour 

NAAQS for PM25." 
73 

243.120(c)(l) 50.13(a) Changed "national primary and 

secondary ambient air quality standards 

for patiiculate matter are ... annual 

arithmetic mean concentration, and ... 

24-hour average concentration" to "2006 

primary and secondary annual average 

NAAQS for particulate matter is ... , 

annual arithmetic mean concentration, 

and the 2006 primary and secondary 24-

hour NAAQS for PM10 is ... , 24-hour 

average concentration,"; changed 

"micrograms per cubic meter (~g/m )" 

to the defined term "~g/m "; removed 

the parenthetical "(patiicles with an 

aerodynamic diameter less than or equal 

to a nominal2.5 micrometers)," which 

has become the basis for a definition of 

"PM2.5" 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)(l )(A) 50.13(a)(l) Changed "a reference method" to the 

defined abbreviation "an FRM"; 

changed "this part" to "40 CFR 50, 

incmporated 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 List of Designated Methods, 

incorporated by reference in Section 

243.108." 

243.120(c)(l )(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 part 53 of this chapter" to "in List 

of Designated Methods, incorporated by 

reference in Section 243.108." 
74 

243.120(c)(2) 50.13(b) Changed "annual primmy and secondary 

PM2.5 standards are" to singular "2006 

primary and secondary annual average 

NAAQS for PM2.5 is"; changed "this 

part" 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 primary and secondary 

24-hourNAAQS for PM2.5 is"; changed 

"this part" 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 conesponding 

federal regulations. 

243.122(a) 50.4 heading Changed "national primary ambient air 

quality standards" to "1971 primary 

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 "pmis per million 

(ppm)" to the defined te1m "ppm"; 

changed "shall" to "must" (twice). 

243.122(a)(2) 50.4(b) Changed "standard" to "1971 primary 

24-hour NAAQS for sulfur oxides"; 

changed "parts per million (ppm)" to the 

defined term "ppm"; changed "shall" to 

"must" (three times). 
75 

243.122(a)(3) 50.4(c) Changed "shall" to "must"; changed 

"sulfur dioxide" to the defined 

abbreviation "S02"; 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 pa1i 53 of this chapter" to "in 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.)." 

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 primary 

annual average and 24-hour NAAQS for 

sulfur oxides ... after fulfillment of the 

conditions recited by USEPA in 

corresponding 40 CFR 50.4(e)" and 

deleted all following material. 
76 

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 defmed term "ppm"; 

changed "3-hour" to written "threehour" (twice); changed "shall" to "must" 

(three times); changed "nonoverlapping" 

to hyphenated "non-overlapping"; 

changed "1" 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 part 53 of this chapter" to "in List 

of Designated Methods, incorporated by 

reference in Section 243.1 08." 
77 

243.122(b)(3) 50.5(c) Changed "3-hour" to written "threehour" (six times); changed "shall" to 

"must" (three times); changed "3" to 

written "three." 

243.122(b) Board note 50.5 generally Added explanation of the delivation of 

subsection (b). 

243.122(c) 50.17 heading Changed "national p1immy and 

secondary ambient air quality standards 

for sulfur oxides (sulfur dioxide)" to 

"1987 primary and secondary NAAQS 

for PM10." 

243.122(c)(l) 50.17(a) Changed "national p1immy !-hour 

annual ambient air quality standard for 

oxides of sulfur" to "2010 primary onehour NAAQS for sulfur oxides"; 

changed "parts per billion (ppm, which 

is I part in I ,000,000,000)" to the 

defined te1m "ppb"; changed "sulfur 

dioxide (S02)" to the defmed 

abbreviation "S02." 

243.122(c)(2) 50.17(b) Changed "!-hour primmy ambient 

standard" to "2010 one-hour primary 

NAAQS for sulfur oxides"; changed "Ihour" to written "one-hour"; changed 

"this part" to "40 CFR 50, incorporated 

by reference ... Section 243.108." 

243.122(c)(3) 50.17(c) Changed "standard" to "20 I 0 one-hour 

primary NAAQS for sulfur oxides"; 

changed "appendix A or A-1" to 

"appendix A-1 or A-2"; changed "this 

part" 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 pa1i 53 of this chapter" 

to "in List of Designated Methods, 

incorporated by reference in Section 

243.108." 
78 

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 of this 

Section with that of the corresponding 

federal regulation. 

243.123(a) 50.8(a) Changed "national primmy ambient air 

quality standards" to "1971 eight-hour 

and one-hour p1imary NAAQS"; added 

"as follow." 

243.123(a)(l) 50.8(a)(1) Changed "an 8-hour average 

concentration" to written "an eight-hour 

average concentration of' and moved to 

the beginning of subsection (a)(1 ); 

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 1-hour average 

concentration" to written "an eight-hour 

average concentration of' and moved to 

the beginning of subsection (a)(2); 

changed "pmts 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." 
79 

243.123(b)(l) 50.8(b )(I) Changed "a reference method" to the 

defined abbreviation "an FRM''; added 

"of 40 CFR 50, incorporated by 

reference ... Section 243.108"; added 

"by USEP A and listed in" after "and 

designated"; changed "in accordance 

with part 53 of this chapter" to "in List 

of Designated Methods, incorporated by 

reference in Section 243.1 08." 

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 part 53 of this chapter" to "in List 

of Designated Methods, incorporated by 

reference in Section 243.108." 

243.123(c) 50.8(c) Changed "8-hour" to written "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." 

243.123(d) 50.8(d) Corrected the spelling "compalision" to 

"comparison"; changed "shall" to 

"must" (twice); changed "patts per 

million" to the defined term "ppm." 

243.123 Board note 50.8 generally Added explanation of the delivation of 

Section 243.123. 

243.124 50.11 generally Replaced the existing language of this 

Section with that of the corresponding 

federal regulations. 

24 3 .124 heading 50.11 heading Changed "national primary ambient air 

quality standards" to singular "nitrogen 

oxides (nitrogen dioxide as indicator)." 
80 

243.124(a) 50.11(a) Changed "national primmy ambient air 

quality standard for oxides of nitrogen" 

to "1971 primary annual average 

NAAQS for nitrogen oxides"; changed 

"parts per billion" to the defmed 

abbreviation "ppb"; added "(N02)" as a 

defined abbreviation after "nitrogen 

dioxide." 

243.124(b) 50.ll(b) Changed "national primmy !-hour 

ambient air quality standard for oxides 

of nitrogen" to singular, written, and 

with defmed abbreviations "20 10 

primary one-hour NAAQS for nitrogen 

oxides"; changed "nitrogen dioxide" to 

the defmed abbreviation "N02." 

243.124(c) 50.ll(c) Changed "national p1imary ambient air 

quality standard for nitrogen dioxide" to 

singular "1971 secondm·y annual 

average NAAQS for nitrogen oxides"; 

changed "pa1ts per billion" to the 

defined abbreviation "ppb"; changed 

"micrograms per cubic meter" to 

"J.lg/m3"; added "measured in the air as 

N02" as a parenthetical offset by a 

comma. 

243.!24(d) 50.ll(d) Changed "shall" to "must"; added "in 

subsections (a) through (c) of this 

Section" for enhanced clarity. 

243.!24(d)(l) 50.11 ( d)(l) Changed "a reference method" to the 

defined abbreviation "an FRM"; 

changed "this pa1t" to "40 CFR 50, 

incorporated by reference ... Section 

243.108"; added "and designated by 

USEPA and listed in List of Designated 

Methods, incorporated by reference in 

Section 243.108." 
81 

243.124(d)(2) 50.11 ( d)(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 List 

of Designated Methods, incorporated by 

reference in Section 243.108." 

243.124(e) 50.ll(e) Changed "annual p1imary standard" to 

"1971 primary annual average NAAQS 

for nitrogen oxides"; added "in 

subsections (a) of this Section" for 

enhanced clarity; changed "this pmt" to 

"40 CFR 50, incorporated by reference 

... Section 243.108." 

243.124(f) 50.ll(f) Changed "!-hour primary standard" to 

"2010 primary one-hourNAAQS 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) 50.11 (g) Changed "secondary standard" to 

singular "1971 secondary annual 

average NAAQS for nitrogen oxides"; 

added "in subsection (c) of this Section" 

for enhanced clarity. 

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, 50.10, and 50.15 Replaced the existing language of this 

generally Section with that of the corresponding 

federal regulations. 

243.125(a) 50.9 heading Changed "national !-hour primary and 

secondary ambient air quality standards" 

to singular "1979 primary and secondary 

one-hour NAAQS." 
82 

243.125(a)(l) 50.9(a) Changed "national !-hour primary and 

secondary ambient air quality standards 

for ozone" to singular "1979 primary 

and secondary one-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" (twice); added "by USEPA" 

after "and designated"; changed "in 

accordance with part 53 of this chapter" 

to "and listed in List of Designated 

Methods, incmporated by reference in 

Section 243.1 08"; changed "standard" to 

"NAAQS"; changed "parts per million" 

to the defined abbreviation "ppm." 

243.125(a)(2) 50.9(b) Changed "!-hour standards" to singular 

"1997 primary and secondary NAAQS 

for one-hour ozone"; changed "8-hour 

0 3 standards under" to "the 2008 

primary and secondary eight-hour 

NAAQS for ozone set fmth in"; changed 

"the !-hour NAAQS" to "USEP A has 

stated that in conesponding 40 CFR 

50.9(b) that the primar·y and secondary 

one-hour NAAQS for ozone"; added "by 

USEP A" after "designation of that 

area"; changed "pursuant to section I 07 

of the Clean Air Act" to "42 USC 7407" 

and moved it from after "8-hour ozone 

NAAQS" to follow "by USEPA"; 

changed "standard" to "NAAQS"; 

changed "8-hour ozone NAAQS" to 

"2008 primary and secondary eight-hour 

NAAQS for ozone"; changed passivevoice "area designations ... are codified 

in 40 CFR part 81" to active-voice 

"USEP A has codified the area 

designations ... in 40 CFR 81.314." 

243.125(a) Board note 50.9(b) generally, 51.905, Added explanation of the derivation of 

and 81.314 this subsection (a); added explanation of 

the revocation of the one-hour standard · 

and the retention in this subsection (a). 
83 

243.125(b) 50.1 0 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(b)(l) 50.10(a) Changed "level of the national 8-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 USEP A" after "and designated"; 

changed "in accordance with part 53 of 

this chapter" to "and listed in List of 

Designated Methods, incmporated by 

reference in Section 243.108"; changed 

"parts per million (ppm)" to the defined 

abbreviation "ppm"; changed "8-hour" 

to written "eight-hour." 

243.125(b)(2) 50.10(b) Changed "8-hour primruy and secondary 

ozone ambient air quality standards are" 

to singular "1997 primruy and secondary 

eight-hour NAAQS for ozone is"; ; 

changed "8-hour" to written "eighthour"; changed "this part" to "40 CFR 

50, incorporated by reference ... 

Section 243.108." 
84 

243.125(b )(3) 50.10(c) Added "USEP A has stated in 

corresponding 40 CFR 50.1 0( c) that"; 

changed "1997 ozone NAAQS set forth 

in paragraph (a) of this section" to "1997 

primary and secondary eight-hour 

NAAQS for 0 3 set forth in subsection 

(b)(l) of this Section"; changed "1 year" 

to written "one year"; changed 

designation of the area" to "USEP A 

designation of that area"; changed 

"pursuant to section 1 07 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"; changed "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' from after 

"notwithstanding"; changed "2008 

ozone NAAQS under" to "2008 primmy 

and secondmy eight-hour NAAQS for 

ozone set forth 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(b)(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 secondary 

NAAQS for ozone" area moved the 

statement into this Board note; changed 

"40 CFRpart 81" to "40 CFR 81.314"; 

added a statement relative to future 

removal of the 1997 standards when 

they m·e clearly obsolete or USEPA 

removes them. 
85 

243.125(b) Board note 50.! 0 generally Added explanation of the de1ivation of 

this subsection (b). 

243.125(c) 50.15 heading Changed "national primary and 

secondary ambient air quality standards 

for ozone" to singular "2008 primary 

and secondary eight-hour primary and 

secondary NAAQS for 0 3." 

243.125(c)(l) 50.15(a) Changed "level of the national 8-hour 

primary and secondary ambient air 

quality standards for ozone" to singular 

"2008 primmy 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 defmed 

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 List of 

Designated Methods, incorporated by 

reference in Section 243.108." 

243.125(c)(2) 50.15(b) Changed "8-hour primmy and secondary 

mnbient air quality standards" to 

singular "2008 primmy and secondary 

eight-hour NAAQS for ozone"; changed 

"3-year" to written "three-year"; 

changed "8-hour" to w1itten "eighthour"; changed "this pa11" to "40 CFR 

50, incorporated by reference ... 

Section 243.108." 

243.125(c) 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 co!Tesponding 

federal regulations. 
86 

243.126(a) 50.12 heading Changed "national prima1y and 

secondary ambient air quality standards" 

to singular "1978 primary and secondary 

NAAQS." 

243.126(a)(l) 50.12(a) Changed "national prin1my and 

secondary ambient air quality standards 

for lead ... are" to singular "the 1978 

primary and secondary quarterly average 

NAAQS for lead ... is"; changed "a 

reference method" to the defmed 

abbreviation "an FRM"; changed "this 

part" to "40 CFR 50, incorporated by 

reference ... Section 243.108"; added 

"and designated by USEP A and listed in 

List of Designated Methods, 

incorporated by reference in Section 

243.108" (twice); changed "equivalent 

method" to the defmed abbreviation 

"FEM." 
87 

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 p1imary and 

secondary NAAQS for lead set fmth in 

subsection (b) of this Section"; changed 

"lead NAAQS set forth in this section" 

to "the 1978 primary and secondary 

NAAQS for lead"· chancred "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 "and or" to "or." 

243.125(a) Board note 50.12 generally Added explanation of the de1ivation 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." 
88 

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 defmed 

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 part" to "40 CFR 50, 

incorporated by reference ... Section 

243.108"; added "byUSEPA and listed 

in" after "and designated"; changed "in 

accordance with part 53 of this chapter" 

to "in List of Designated Methods, 

incorporated by reference in Section 

243.108." 

243.126(b )(l)(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 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 

p1imary 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/mh 

243.126(b) Board note 50.16 generally Added explanation of the derivation of 

this subsection (b). 
89 

243.TableA Table I to 50.14(c) Moved the tabulated material from the 

body of the regulations into an appended 

table. 

243.Table A heading Table I to 50.14(c) Reformatted the text from large and 

heading small caps to standard title text; omitted 

"for data to be used in designations." 

243.Table A column I Table I to 50.14(c) Omitted "pollutant" and "standard," in 

heading column I heading favor of the single entry title "NAAQS"; 

changed "promulgation date" to 

"regulatory citations"; and replaced the 

virgules separating entries with hard 

returns. 

243.Table A row I Table I to 50.14(c) row I Changed "PM2.5/24-Hr standard" to 

column I entry column I entry "2006 24-hour PM2.5"; separated the 

name of the NAAQS from the 

parenthetical level by a hard return; 

added citations to the Illinois and 

corresponding federal rules; added the 

Federal Register citation for the 

pertinent notice of adopted rule. 

243.Table A row I Table I to 50.14(c) row I Omitted the marking for endnote "a." 

column 3 entry column 3 enh·y 

243.Table A row I Table I to 50.14(c) row I Omitted the marking for endnote "a." 

column 4 entry column 4 entry 

243.Table A row 2 Table I to 50.14(c) row 2 Changed "ozone/8-Hr standard" to 

column I entry column I enh·y "2008 eight-hour ozone"; separated the 

name of the NAAQS from the 

parenthetical level by a hard return; 

added citations to the Illinois and 

co!Tesponding federal rules; added the 

Federal Register citation for the 

pertinent notice of adopted rule. 

243.Table A row 2 Table I to 50.14(c) row 2 Omitted the marking for endnote "a" 

column 3 enh-y column 3 enh·y (twice); changed "occurs" to past-tense 

"occutTed"; omitted the marking for 

endnote "b." 
90 

243.Table A row 2 Table I to 50.14(c) row 2 Omitted the marking for endnotes "a" 

column 4 entry colunm 4 enl!y 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/l-hour standard" to 

colunm I enl!y colunm I entry "2010 one-hour nitrogen oxides (as 

N02)"; separated the name of the 

NAAQ8 from the parenthetical level by 

a hard return; cmrected "80-100 PPB, 

final level TBD)" to "(I 00 ppb )"; added 

citations to the Illinois and 

corresponding federalmles; added the 

Federal Register citation for the 

pe11inent 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 enl!·y colunm 3 entry (three times). 

243.Table A row 3 Table I to 50.14(c) row 3 Omitted the marking for endnote "a" 

colunm 4 entry column 4 entry (three times). 

243.Table A row 4 Table I to 50.14(c) row 4 Changed "802/1-hour standard" to 

colunm I entry colunm I enl!y "2010 one-hour sulfur oxides (as 802)"; 

separated the name of the NAAQ8 from 

the parenthetical level by a hard return; 

co1rected "50-I 00 PPB, final level 

TBD)" to "(75 ppb)"; added citations to 

the Illinois and corresponding federal 

mles; added the Federal Register 

citation for the pe11inent 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 enl!·y column 3 entry (three times); changed "occurs" to pasttense "occurred"; 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 entry colunm 4 entry (three times); changed "occurs" to pasttense "occurred"; 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. 
91 

243.TableA 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 de1ivation of 

note note Table A; changed "EPA notes" to 

"USEP A noted"; added "the information 

in" before "this table"; changed "EPA" 

to "that USEPA"; 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 

errors 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 

243.102 heading corresponding 40 C.F.R. 50.2. 

243 table of contents, Board Added the parenthetical "(Repealed)" to accommodate 

243.104 heading repeal of this Section, which has not direct counterpart in 

40 C.F.R. 50. 

24 3 table of contents, Board Added the parenthetical "(Repealed)" to accommodate 

243.106 heading repeal of this Section, which has not direct counterpart in 

40 C.F.R. 50. 

243 table of contents, Board Changed "8-Hour Ozone" to "Ozone" to accommodate 

243.122 heading consolidation of corresponding 40 C.F.R. 50.9, 50.10, 

and 50.15 into a single provision. 

24 3 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. 
92 

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 not direct 

counterpatt in 40 C.F.R. 50 .. 

243 table of contents, Board Changed "Appendix" to uppercase "APPENDIX" to 

243.Appendix B 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 not direct 

counterpart in 40 C.F.R. 50 .. 

243 table of contents, Board Changed "Appendix" to uppercase "APPENDIX" to 

243.Appendix C compmt 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 not direct 

counte1part in 40 C.F.R. 50 .. 

243 authority note Board Changed "Section 10" to "Sections 7.2 and 10"; replaced 

the obsolete Illinois Revised Statutes citation with the 

current Illinois Compiled Statutes citation. 

243 source note Board Removed the obsolete citations "4 PCB 191" from after 

"R71-23" and "46 PCB 125" from after "R80-ll." 

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 counte1part 

in 40 C.F.R. 50. 

243.107 Board Removed the word "except," which does not exist in the 

corresponding 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 suppmt 

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. 
93 

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 "US EPA, 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" entry. 

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" ently; 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 assetted by the Office of the Secretary of 

State; added the parenthetical "(Repealed)" to 

accommodate repeal of this Section, which has not direct 

countetpatt in 40 C.F.R. 50 .. 

243.Appendix A Board Repealed the obsolete rules conversion table. 
94 

243.Appendix B Board Changed "Appendix" to uppercase "APPENDIX" to 

heading comport 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 not direct 

counterpart in 40 C.P.R. 50 .. 

243.Appendix B Board Repealed the obsolete rules conversion table. 

243.Appendix C Board Changed "Appendix" to uppercase "APPENDIX" to 

heading comport 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 not direct 

counterpmt in 40 C.P.R. 50 .. 

243.Appendix C Board Repealed the obsolete past compliance dates table. 

ORDER 

The Board directs the Clerk to provide notice in the Illinois Register of the following 

proposed amendments to the Illinois mnbient air quality regulations at 35 Ill. Adm. Code 243: 

Section 

243.101 

243.102 

243.103 

243.104 

243.105 

243.106 

243.107 

243.108 

Section 

243.120 

243.121 

TITLE 35: ENVIRONMENTAL PROTECTION 

SUBTITLE B: AIR POLLUTION 

CHAPTER I: POLLUTION CONTROL BOARD 

SUBCHAPTER 1: AIR QUALITY STANDARDS AND EPISODES 

PART243 

AIR QUALITY STANDARDS 

SUBPART A: GENERAL PROVISIONS 

Definitions 

Pream8leScope 

Applicability 

N ondegradation (Repealed) 

Air Quality Monitming Data Influenced by Exceptional Events 

Monitoring (Repealed) 

Reference Conditions 

Incorporations by Reference 

SUBPART B: STANDARDS AND MEASUREMENT METHODS 

PM10 and PM2.s 

Particulates (Repealed) 
243.122 

243.123 

243.124 

243.125 

243.126 

Sulfur Oxides (Sulfur Dioxide) 

Carbon Monoxide 

95 

Nitrogen Oxides (Nitrogen Dioxide as Indicator) 

g Hottr Ozone 

Lead 

A]3]3eaeiK 243.APPENDIX A Rule into Section Table (Repealed) 

A]3]3eaeiK 243.APPENDIX B Section into Rule Table (Repealed) 

f<]3]3eBEiiJ< 243.APPENDIX C Past Compliance Dates (Repealed) 

243.TABLE A Schedule of Exceptional Event Flagging and Documentation Submission 

for New or Revised NAAQS 

AUTHORITY: Implementing geetioa Sections 7.2 and 10 and authorized by Section 27 of the 

Environmental Protection Act (Ill. Rev. gtat. 1991, ea. Ill 112, J3ars. 1010 aae 1027) [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, filed and effective Apiill4, 1972; amended in R80-ll, 46 PCB 125, at 6 Ill. Reg. 

5804, effective April22, 1982; amended in R82-l2, at 7 Ill. Reg. 9906, effective August 18, 

1983; codified at 7 Ill. Reg. 13630; amended in R91-35 at 16 Ill. Reg. 8185, effective May 15, 

1992; amended in R09-19 at 35 Ill. Reg. 18857, effective October 25, 2011; amended in Rl3-ll 

at 37 Ill. Reg. , effective _________ _ 

SUBPART A: GENERAL PROVISIONS 

Section 243.101 Definitions 

a) EKeept as stateEl in this Part aaEl Bnless a Elif:fere!Tt meaain:g ef a term is elear H·effi 

its eoflleKt, !fle eefmitioas oftem1s usee in this Part saall be !fle same as !flose 

HseEI ia tfle BavireBrBefllal Proteetioa Aet [415 ILCg 5] (Aet). 

b) All terms taat a]3]3ear ia this Part aave tae Elefmitioas Sfleeifiee by 35 Ill. ,\Elm. 

Coee 201 or 211. 

For the purposes of this Part. te1ms listed below will have the meanings attributed to them in this 

Section. As used in this Part, all terms not defmed in this Section will have the meaning given 

them by the Act: the CAA, incorporated by reference in Section 243.1 08; or 35 Ill. Adm. Code 

201.102. 

"Act" means the Environmental Protection Act [415 ILCS 5]. 

"Agency" means the Illinois Enviromnental Protection Agency. 

"Ambient air" means that portion of the atmosphere. external to buildings. to 

which the general public has access. 
96 

"Clean Air Act" or "CAA'' means the federal Clean Air Act 42 USC 7401 et. seq, 

as amended, incmporated by reference in Section 243.108. 

"Exceedance of a NAAQS" means one occunence of a measured or modeled 

concentration that exceeds the specified concentration level of such standard for 

the averaging period specified by the standard. 

"Exceptional event" means an event that fulfills all of the following criteria: 

The event affects air quality; 

The event is not reasonably controllable or preventable; 

The event is an event caused by human activity that is unlikely to recur at 

a particular location or a natural event; and 

The event is detetmined 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 equivalent 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 equivalent method pursuant to 40 CFR 53 and which is included in List of 

Designated Methods. including later updates. as incmporated 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 incmporation by 

reference in Section 243.108. 

BOARD NOTE: Derived from 40 CFR 50.1Cf) (defmition of"equivalent 

method"), 50.11Cd)(2) (parenthetical definition of"FEM"), and 53.1 (definition of 

"federal equivalent method"). The clause "including later updates" in this 

definition is intended to exclude methods canceled by USEPA pursuant to 40 

CFR 53.11 or 53.16 for which the cancellation is included in the updates to List of 

Designated Methods incomorated 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 or from an appendix to 40 CFR 50. 
97 

"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, incorporated 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 24 3 .I 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 incmporation by reference in Section 

243.108. 

BOARD NOTE: Derived from 40 CFR 50. I (f) (defmition of"reference method") 

and 53.1 (defmition 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 fi·om an appendix to 40 CFR 

50. 

"Micrograms per cubic meter" or "ug/m3

" means one millionth (I 0'6) of a gram of 

a contaminant per cubic meter of ambient air, as measured and determined by the 

methods prescribed for that contaminant. 

BOARD NOTE: The Board added this definition and that for "milligrams per 

liter" Cin1mediately below). 

"Milligrams per cubic meter" or "mg/m3

" means one thousandth (I 0'3) of a gram 

of a contaminant per cubic meter of ambient air, 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 throughout the United States. 

BOARD NOTE: The Board added this definition, derived from the definition in 

"Terms ofEnviromnent: Glossary, Abbreviations, and Acronvms" (December 

1997), EPA 175-B-97-001. at 30. USEPA has codified the NAAOS at 40 CFR 

50. 

BOARD NOTE: The Board added this definition based on the definition in 

"Terms ofEnviromnent: Glossary. Abbreviations, and Acronyms" (December 

1997), document number EPA 175-B-97-001, USEPA. Office of 

Communications, Education, and Public Affairs, at 30. 

"Natural event" means an event in which human activity plays little or no direct 

causal role. 
98 

"Parts per billion" or "ppb" means the ratio of the pm1s of a specified contaminant 

to a billion pat1s of air by weight (I: I o-9

). as measured and determined by the 

methods prescribed for that contaminant. 

BOARD NOTE: The Board added this definition and that for "pm1s per million" 

(immediately below). derived from the parentheticals in 40 CFR 50.4(a) and (b) 

and 50.17(a) and the definition of"parts per billion (ppbl/parts per million (ppm)" 

in "Terms of Environment: Glossary. Abbreviations. and Acronyms" (December 

1997). EPA 175-B-97-001. at 34. 

"Parts per million" or "ppm'' means the ratio of the pm1s of a specified 

contaminant to a million p3!1s of air by weight (I: I 0'6

). as measured and 

detennined by the methods prescribed for that contaminant. 

BOARD NOTE: The Board added this definition and that for "parts per million" 

(immediately below). derived from the parentheticals in 40 CFR 50.4(a) and (b) 

and 50.17(a) and the definition of "pm1s per billion (ppbl/parts per million (ppm)" 

in "Tetms of Environment: Glossary. Abbreviations. and Acronyms" (December 

1997). EPA 175-B-97-001. at 34. 

"PM10" means pm1iculate matter that has an aerodvnamic diameter less than or 

egual to a nominal I 0 micrometers (l!m). 

BOARD NOTE: The Board added this definition. derived from the parenthetical 

definition in 40 CFR 50.6(c). 

"PM, 5 " means p3!1iculate matter that has an aerodvnamic -diameter less than or 

egual to a nominal 2.5 micrometers (l!m). 

BOARD NOTE: The Board added this definition. derived from the parenthetical 

definition in 40 CFR 50. 7(a). 

"Traceable" means that a local standard has been compared and cet1ified either 

directly or via not more than one intetmediate standard, to a primary standard, 

such as a National Bureau of Standards Standard Reference Material (NBS SRMl. 

or a USEP A/NBS-approved Certified Reference Material CCRMl. 

"USEPA" means the United States Environmental Protection Agency. 

BOARD NOTE: Detived from 40 CFR 50.1Ccl. The Board has used "USEPA" 

in segments of text where USEPA has used "Administrator." where action by 

USEPA is clearly contemplated. Othetwise. the Board has retained the term 

"Agency" as defined in this Section. 

BOARD NOTE: Derived from 40 C.P.R. 50.1 (2012). except as otherwise more specifically 

indicated. 

(Source: Amended at 37 Ill. Reg. ____ ,, effective----------' 
99 

Section 243.102 Preamble Scope 

a) Air Ejt!alit)· staadards are lrn1its ea atmespherie eeaeeffiratieas ef air eeffiamrnaffis 

estalJiished fer the pt>fj3ese efpreteetiag JlOOiie health aad welfare. The le'<els ef 

air Ejt!ality desigaated lJy the staadards are desigaed te JlFeleet agarnst injury te 

ffilmaa, Jllaffi er aaimallife aad they <n·e further iffieaded te allow maKimum 

SRjeymeffi eflife aad JlreJlel1y eeasisteal v1ith the iffieffi efthe Aet. 

a) This Pat1 sets forth the N AAQS adopted by USEP A under section 109 of the 

CAA (42 USC 7409) and incorporated into this Patt pursuant to 415 ILCS 5/7.2 

and lOCH). 

13) The first use ef our air reseurees is to sestaia life. Afr effierrng the respiratory 

!rae! must aot meaaee health. Therefore, the air EJ:Hality staadards set mtiS!, as a 

minimHm, provide air whieh v1ill aet adversely affeet, through aStile er ehrenie 

S)'H'ljlloms, the health of the eeHlffil>nity. A&verse health effeets iaelude aet oaly 

the possilJie prodtietioa aad aggnwatiea of disease, lJut also iffierfereaee with 

lJedily fuRetieas. The staadards ha-ve also takea iffie aeeetiffi seilrng, eerresiea, 

vegetatioa damage aad ether lmmaa effeets. 

b) National mimary ambient air quality standards (primary NAAQS) define levels of 

air quality that USEPA has judged are necessaty. with an adequate margin of 

safety. to protect the public health. National secondary ambient air qualitv 

standards (secondary NAAQS) define levels of air qualitv that USEPA has judged 

necessary to protect the public welfare from any known or anticipated adverse 

effects of a pollutant. Such standards are subject to revision. and additional 

primary and secondary NAAQS may be promulgated as USEP A deems necessaty 

to protect the public health and welfare. 

e) Prllilary amlJieffi air EJ:tiality staad<n·ds defiae levels of air Ejt!ality whieh are 

aeeessary, with aa adeEjt!ate a1argia efsafet)·, to proteet the JlOOiie health. 

Seeoadary aRlllieffi air Ejt!ality slafldards defiae levels of air Ejt!ality whieh are 

aeeessary to preteet the JlOOiie welfare fwm any knovlfl or affiieijlated ad-verse 

effeets of a JlOihilffilt. 

c) The promulgation of primaty and secondary NAAQS must not be considered in 

any manner to allow significant deterioration of existing air quality in any pmtion 

of this State. 

d) The staadards are mere thaa goals. They are legally SRfereealJie limitatioas, aad 

aey Jlersea eat>sing or eomrilJutrng to a violatioa ef the stafldards is sooj eet to 

enfereemeffi Jlroeeediags uader the Aet The s!E!l'ldards have also lJeea desigaed 

fer use as a lJasis fer the developmeffi of iffijllemeffiatioa plaas lJy State aad loeal 

ageaeies fer the alJatemSR! aad eeffirel of pollutaat emissieas from eJlistiag 

seurees, aad fer the determiaatiea of air eoffiamiaaffi emissiea limitatieas to 
100 

iflSHFe teat flBflHlatiefl aaa e68fl8HH6 grewte treflaS ae fl8t aaa te tee regiea's air 

flBll!itiea flFealems. 

BOARD NOTE: Derived from 40 CFR 50.2 (2012). 

(Source: Amended at 37 Ill. Reg. ___ , effective _________ _J 

Section 243.103 Applicability 

The standards in this Pmt are ~!llieaale ;mlliy_throughout the State of Illinois, except as 

othetwise provided in this Part. 

(Source: Amended at 37 Ill. Reg. ____ , effective-----------' 

Section 243.104 Nondegradation (Repealed) 

El<istiag amaiefll air EJ:aality teat is setter teaa tee estaaliseea amaieat air EJ:Hality staaaaras at tee 

Elate efteeir aEie!3tiea will ae maifllaiaea ia its flFeseflt ftige EJ:Hality. Saee aaal3iefll air EJ:!iality 

seall Ret ae lewerea HH!ess aaa Hfllil it is fli'SYea te tee lilffieis Ew:ireamefltal Preteetiea Ageaey 

(Ageae)0 teat tee eeaage isjastifiaale as a resalt efaeeessary eeeaemie aaa seeial aeYele!lmeflt 

aaa will aet imerfere wite er eeeeme iajarieas te eamaaeealte er welfare. 

(Source: Repealed at 37 Ill. Reg. ____ , effective-----------' 

Section 243.105 Air Qualitv Monitoring Data Influenced bv Exceptional Events 

a) Requirements. 

]) The Agency may request USEP A to exclude from use in detenninations 

data showing an exceedance of an NAAQS that is directly due to an 

exceptional event. The Agency must demonstrate to USEP A that such 

event caused a specific air pollution concentration at a pmticular air 

qualitv 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 NAAQS and the event in accordance with 

paragraph ( c )(3 )(D) of this section. 

b) Detetminations by USEP A. USEP A has stated the criteria for making a 

detennination to exclude data as follow: 

I) Exceptional events. USEP A has stated that it will exclude data from use 

in detetminations of exceedance of an NAAQS where the Agency has 

demonstrated that an exceptional event caused a specific air pollution 

concentration in excess of one or more NAAQS at a particular air quality 
101 

monitoring location. and the Agency othe1wise satisfies the requirements 

of 40 CFR 50.14. 

2) Fireworks displays. USEPA has stated that it will exclude data from use 

in determinations of exceedance of an NAAQS where the Agency has 

demonstrated that emissions from fireworks displays caused a specific air 

pollution concenh·ation in excess of one or more NAAQS at a pmiicular 

air quality monitoring location. and the state otherwise satisfies the 

requirements of 40 CFR 50.14. USEPA has stated that such data will be 

treated in the same manner as exceptional events under this rule. provided 

the Agency has demonstrated that such use of fireworks is significantly 

integral to traditional national, ethnic. 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 

detenninations of exceedance of an NAAQS where the Agency has 

demonsh·ated that emissions from prescribed fires caused a specific air 

pollution concentration in excess of one or more NAAQS at a pmiicular 

air quality monitoring location. and the Agency otherwise satisfies the 

requirements of 40 CFR 50.14. provided that such emissions are fi·om 

prescribed fires that USEP A determines meets the defmition of 

"exceptional event'' in Section 243.101, and provided that the Agency has 

ce1iified to USEP A that the State has adopted and is implementing a 

Smoke Management Program CSMP) 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 

Agency must undertake a review of the State's approach to ensure public 

health is being protected and must include consideration of development 

of a SMP. 

BOARD NOTE: In each of coJTesponding 40 CFR 50.14(b)Cll. (b)(2) and Cb)(3). 

USEP A stated "EPA shall exclude data from use in detenninations of 

exceedances and NAAQS 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." Fmiher. the Board has relied on 

the defined term "exceedance of an NAAQS." 

c) Schedules and Procedures. 

]) Public notification. 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)J. the Agency's delegatee. must notify the public promptly whenever an 

event occurs or is reasonably anticipated to occur which may result in the 

exceedance of an NAAQS. 
102 

2) Flagging of data. 

A) The Agency must notify USEPA of the State's intent to exclude 

one or more measured exceedance of an NAAQS as being due to 

an exceptional event by placing a flag in the appromiate field for 

the data record of concern that has been submitted to the federal air 

guality system CAQS) database. 

B) Flags placed on data in accordance with this Section must be 

deemed infmmational only, and the data must not be excluded 

from dete1minations with respect to an exceedance of an NAAQS 

unless and until after US EPA notifies the Agency ofUSEPA 

concurrence following the Agency's submittal of a demonstration 

pursuant to subsection ( c )(3) ofthis Section by placing a 

concurrence flag in the appropriate field for the data record in the 

AQS database. 

Cl Flags placed on data as being due to an exceptional event. together 

with an initial description of the event. must be submitted to 

USEPA not later than July 1st 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) corresponds with 40 CFR 

50.14(c)(2)(iv), which has expired by its own te1ms. This 

statement maintains stmctural 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 terms. This statement maintains 

stmctural consistency with the federal regulations. 

F) USEPA has stated that when USEPA sets a NAAQS 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 descriptions. and providing detailed 

data documentation in AQS for the initial designations of areas for 

those NAAQS. Table A to this Part 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. USEP A has stated that it will revise the table upon 

which Table A to this Part is based as necessary to accommodate 

revised data submission schedules for new or revised NAAQS. 

3) Submission of demonstrations. 
103 

A) When the Agency has flagged data as being due to an exceptional 

event and is requesting exclusion of the affected measurement 

data, tbe Agency must, after notice and opportunitv 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 quarter 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 the public 

comments it received along with its demonstration to USEP A 

B) This subsection (c)(3)(B) corr-esponds witb 40 CFR 50.14(b)(3)(ii). 

which pertains only to a repmting period and opportunity to 

demonstrate exceptions that has passed. This statement maintains 

stmctmal consistency with the federal regulations. 

C) This subsection (c)(3)(B) corr-esponds with 40 CFR 50.14(b)(3)(ii), 

which pertains only to a reporting period and opportunity to 

demonstrate exceptional events tbat 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 forth 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 tbe area; 

iii) That the event is associated with a measured concentration 

in excess of normal 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, tbe Agency must 

document that the public comment process was followed. 

BOARD NOTE: Derived from 40 CFR 50.14 (2012). 

(Source: Added at 3 7 Ill. Reg. ___ , effective _________ ....J 
104 

Section 243.106 Monitoring (Repealed) 

Pellatiea levels wi1113e detenniaed 13y HJted er me13ile sam)'lliag statieas 13eyead the )'lremises ea 

whieh a searee is !seated. Statieas 'Nill13e leeated aeeerdiag te the gaildeliaes fer esta13lished 

FHonitorffig aeRveFks as Elevelef)eEl By tHe UHited States EITviroflffieFrtal ProteetioR PrgeBey. 

(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, eJWe)'lt other than for particulate matter (PM2.5) standards contained in Section 

243.120(b) and (c) and lead standards contained in Section 243.126(b), are corr-ected to a 

reference temperature of25°_C, and to a reference pressure of760 millimeters of mercury 

(1 013.2 millibars). Measurements of PM25, for pwposes of comparison to the standards 

contained in Section 243.120(b) and (eLand lead, measmemeats shall for purooses of 

comparison 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 from 40 CFR 50.3 (2012). 

(Source: Amended at 37 Ill. Reg. ____ , effective _________ _, 

Section 243.108 Incorporations by Reference 

The following materials are incorporated by reference. These incorporations do not include any 

later amendments or editions: 

a) Pararesaniliae methed, 4Q CFR §Q, a)'l)'leadiJt A (19S2). 

13) Nea dis)'lersive iaftared SJ3eetrea1etry teehniEjlle, 4Q CFR §Q, a)'lfleRdiK C (19S2), 

39 Fed. Reg. 22391, l>levem13er 2§, 1971. 

e) Celerimetrie methed, 39 Fed. Reg. 22399, Nevem13er 2§, 1971. 

d) O;;mae etflj~eae reaetiea methed, 4 Q CFR §Q, a)'l)'leadiJt D (1982), 3 9 Fed. Reg. 

22392, l>le,·era13er 2§, 1971. 

e) Lead, 4Q CFR §Q, a)'lfleRdiK G (2QQ8). 

f) Refereaee methed fer the detenniaatiea ef)'lartiealate matter as P~'!.w-ffi...the 

atmes)'lhere, 4Q CFR §Q, a)'lfleRdiJt J (199Q). 
105 

g) latefJ3retatieR sf tf!e JllatieRal AmeieRt Air Qt~ality gtaRaaFEls (JIL'.AQg) fer 

]3artiet~late matter, 40 CPR 50, 6J3J3eRaiK K, 73 Pea. Reg. 61144 (Oeteeer 17, 

~ 

h) RefereRee metl!ea fer the aeteFFRinatieR ef J3ar!ielilate matter as PM""'-ffi...the 

atmesJ3l!ere, 40 CPR 50, 6J3J3eRaiK L, 73 Pea. Reg. 6114 4 (Oeteeer 17, 2006). 

i) lffiefjlretatieR eftl!e JIIAAQg fer PM-M, 40 CPR 50, 6J3J3eRaiK Jll, 73 Pea. Reg. 

14 97 (Jaooal)· 9, 200g). 

j) lffiefjlretatieR eftl!e JIIAAQS fer 0~, 40 CPR 50, aJ3J3eRaiK P, 73 Fee. Reg. 16436 

(Marel! 27, 200g). 

k) The Jll-Af,Qg fer Leaa; FiRal Rule, 40 CFR 50, 51, 53, aRe 5g, 73 Fea. Reg. 

66964 (JIIevember 12, 200g). 

I) laterJ3retatieR eftl!e JIIAAQS fer Leaa, 40 CFR 50, 6J3J3eRaill R, 73 Fee. Reg. 

66964 (JIIevemeer 12, 200g). 

Govemment 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 incorporated 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 Pmticulate 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 

243.123. 

Appendix D to 40 CFR 50 (2012) (Reference Measurement Principle and 

Calibration Procedure for the Measurement of Ozone in the Atmosphere). 

referenced in Section 243.125. 
106 

Appendix F to 40 CFR 50 (2012) (Reference Measurement Principle and 

Calibration Procedure for the Measurement of Nitrogen Dioxide in the 

Atmosphere (Gas Phase Chemiluminescence)). referenced in Section 

243.124. 

Appendix G to 40 CFR 50 (2012) (Reference Method for the 

Dete1mination of Lead in Suspended Pm1iculate Matter Collected from 

Ambient Air). referenced in Section 243.126. 

Appendix H to 40 CFR 50 (2012) (Interpretation of the !-Hour Plimary 

and Secondary National Ambient Air Quality Standards for Ozone). 

referenced in Section 243.125. 

Appendix I to 40 CFR 50 (2012) (Interpretation of the 8-Hour Plimary and 

Secondaw National Ambient Air Quality Standards for Ozone). 

referenced in 243.125. 

Appendix J to 40 CFR 50 (2012) (Reference Method for the 

Determination ofPm1iculate Matter as PM10 in the Atmosphere. 

referenced in Section 243.120. 

Appendix K to 40 CFR 50 (2012) (Interpretation of the P1imary and 

Secondary National Ambient Air Quality Standards for Particulate 

Matter), referenced in Section 243.120. 

Appendix L to 40 CFR 50 (2012) (Reference Method for the 

Dete1mination of Fine Particulate Matter as PM,.s in the Atmosphere). 

referenced in Section 243.120. 

Appendix N to 40 CFR 50 (2012) (Interpretation of the Primary and 

Secondary National Ambient Air Quality Standards for Pa11iculate 

Matter), referenced in Section 243.120. 

Appendix 0 to 40 CFR 50 (2012) (Reference Method for the 

Determination of Coarse Particulate Matter as PM10.2.5 in the 

Atmosphere). referenced in appendix 0 to 40 CFR 50 and for use in 

federally required monitming by the NCore system pursuant to 40 CFR 

~ 

Appendix P to 40 CFR 50 (2012) (Interpretation of the Primary and 

Secondmy National Ambient Air Quality Standards for Ozone). 

referenced in 243.125. 

Appendix 0 to 40 CFR 50 (2012) (Reference Method for the 

Dete1mination of Lead in Pm1iculate Matter as PM10 Collected from 

Ambient Air). referenced in appendix R to 40 CFR 50. 
107 

Appendix R to 40 CFR 50 (2012) Cintemretation of the National Ambient 

Air Quality Standards for Lead), referenced in Section 243.126. 

Appendix S to 40 CFR 50 (2012) (Intemretation of the P1imary National 

Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen 

Dioxide)), referenced in 243.124. 

Appendix T to 40 CFR 58 (2012) Clntemretation of the Primmy National 

Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide)), 

referenced in Section 243.122. 

Clean Air Act. 42 USC 7401 et seq. (2011) (for definitions of terms only), 

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 Laboratory, Human Exposure & 

Atmospheric Sciences Division (MD-D205-03), Research Triangle Park, NC 

27711. The following documents incomorated by reference are available from 

this source: 

"List of Designated Reference and Equivalent Methods" (December 17, 

20 12) (referred to as "List of Designated Methods" and referenced in 

Sections 243.101,243.120,243.122,243.123.243.124,243.125, 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 fi·om 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 PMw and PM2.5 

a) Staaaanls. The J3rimary aaa seeeaaary alfll3iea! air EIUali!y staaaarEls fer PMw.are 

a maJlilffilm 24 heur a-verage eeaeeffiratiea ef 15Q t±§'m~. The s!aaaaras are 

a!!aiaea v;hea the e)(J3ee!ea ooml3er efaays J3er ealeaaar year v:ilh a 24 heHr 
108 

&verage eeHeel'ltratieH ae8':e l§Q flg/m~ is efjual te er less taaH eHe, as measurea 

aHa aetermiHea iH aeeeraaHee with sullseetieH (e). 

e) Measuremeflt Metaea. fer aetermffiiHg eeHfermaHee wita tl!e PM .. w.amlliel'lt air 

EjUality staHaaras, PMw saall ee measurea ey tae metaea aeserieea iR 4Q CPR §Q, 

aJ3J'18flaiK J er aH efjuivalel'lt metaea aesigHatea J9HrsuaHt te 4Q CPR §3 

(iReerJ9eratea ey refureHee iH SeetieH243.1Q8). Tae staHaaras are attaiHea ·.vaeH 

tl!e eJ'fleetea flllmSer efaays J9er ealeHaar year wita a 24 aeur il':erage 

eeHeeHtratioH aeo1·e 15Q flg/nl is efjual te or less tflaH oHe, as aetermiRea iH 

aeeeraaHee 'Nita 4Q CPR 5Q, af1f1eHaiK K (iHeerJ9eratea ey refureHee iR SeetieH 

243.1Q8). 

e) !i:taHaaras. The j'lrimary aHa seeeHaary ameieHt air Ejllality staHaaras fur P~.<[g 

aFei1) AH al1ffi!al aritl!metie meaH eeHeeHtratieH ef 15.Q flg,'m~ aHa as measurea 

aHa aetermiHea iH eeHfurmaHee wita sueseetieH (a). 

2) f, maKiroum 24 aGUf 69f!Sel'ltratiefl ef35 flg,lm", at tfle gg!fl j'lereeHtile 

value, aHa as measurea aHa aetermiHea iR eeflfermaHee wit!! sullseetieH 

Wo 

a) MeasHremel'lt Metaea fer PJ>.<Ig. fer aetenniRiHg eeHfurmaHee wita the PJ>.<[g 

amlliel'lt air Ejllality staHaaras, PJ>.<[g saall ee measHrea ey tae metaea aeserieea iH 

4Q CPR 5Q, aJ3f1eHaiK L er aH efjll¥:alel'lt metaea aesigHatea J'lliFSli&at te 4Q CPR 

53 (iReefj'lGFatea ey refereHee iR SeetieH243.1Q8). Cemj'lliaHee with tl!e 

staHaaras is aetermiReaHsiHg tae metaeas aHa J9reeeaHres aeserieea iH 4Q CPR 

5Q, ajlj'leHaiK 1'! (ifl69Fj'19fatea ey refureHee ifl Seetiefl 24 3 .I Q8). 

I) The al1ffi!al j'lriroary aHa seeoHaary PJ>.<[g staHaaras are met ·.vaeH tae 

annual arithrnetie fFleaH eeaeeatFatieH, as EletenRffieS. ia aeeerElaHee with 

4Q CPR 5Q, aj'lj'18flaiK Jl!, is less taaH er efjllal te 15.Q flghn~" 

2) The 24 aeHr j'lrimary aHa seeeHaary PJ>.<[g staHaaras are met waeH tae 

98th j'lereel'ltile 24 aelir eeHeel'ltratieH, as aetermiHea iH aeeeraaHee ·.vita 

4Q CPR 5Q, ajlj'leHaiJt 1'!, is less taaH or efjllal to 35 flg,lm"" 

a) 1987 primary and secondary 24-hour NAAQS for PM10. 

1) The level of the 1987 primary and secondary 24-hour NAAQS for PM10 is 

150 ug/m3

• 24-hour average concentration. The 1987 primary and 

secondary NAAQS for PM10 is attained when the expected number of 

days per calendar year with a 24-hour average concentration above 150 

ug/m3

• as dete1mined in accordance with appendix K to 40 CPR 50. 

incorporated by reference in Section 243.108. is equal to or less than one. 
109 

2) This subsection (a)(2) co!Tesponds with 40 CFR 51.6(b), a provision 

marked "reserved" by USEP A. This statement maintains stmctural 

consistency with the conesponding federal regulation. 

3) For the putpose of determining attainment of the 1987 primary and 

secondary 24-hour NAAOS for PM10, pmticulate 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, incorporated 

by reference in Section 243.108. and designated byUSEPA 

and listed in List of Designated Methods, incmporated by 

reference in Section 243.108, or 

B) An FEM designated by USEPA and listed in List of Designated 

Methods, incorporated by reference in Section 243.108. 

BOARD NOTE: This subsection (a) is derived from 40 CFR 50.6 

(2012). USEPA adopted 1997 primary NAAOS 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, 1 000) and the 1997 NAAOS at 69 Fed. Reg. 45595 (July 30, 2004). Thus, the 

1987 primarv and secondary NAAOS for PM10 are included in this subsection (a). 

b) 1997 primary and secondary annual average and 24-hour NAAOS for PM,.s. 

1) The 1997 mimary and secondary annual average NAAOS for PMz.s is 

15.0 ug/m3

, annual arithmetic mean concentration. and the 1997 primary 

and secondary 24-hour NAAOS for PMz.s is 65 ug/m3

• 24-hour average 

concentration, measured in the ambient air as PM2.5 by a method that 

fulfills either of the following requirements: 

A) An FRM based on appendix L of 40 CFR 50. incorporated by 

reference in Section 243.108 and designated by USEPA and listed 

in List of Designated Methods, incorporated by reference in 

Section 243.108: or 

B) An FEM designated by USEPA and listed in List of Designated 

Methods, incmporated by reference in Section 243.108. 

2) The 1997 primary and secondary annual average NAAOS for PMz s is met 

when the annual arithmetic mean concentration, as dete1mined in 

accordance with appendix N of 40 CFR 50, incorporated by reference in 

Section 243.108, is less than or equal to 15.0 ug/m3

• 
110 

3) The 1997 primary and secondary 24-hour NAAOS for PM15 is met when 

the 98th percentile 24-hour concentration. as dete1mined in accordance 

with appendix N of 40 CFR 50. incorporated by reference in Section 

243.108. is less than or egual to 65 ug/m3

. 

BOARD NOTE: This subsection (b) is derived from 40 CFR 50.7 (2012). The 

2006 primary and secondmy annual average and 24-hour NAAOS 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 Cb) because 

USEPA has retained the 1997 standard in 40 CFR 50.6. 

c) 2006 primary and secondary annual average and 24-hour NAAOS for PM:u:. 

1) The 2006 primary and secondary annual average NAAOS for PM, 5 is 

15.0 11g/m3

• annual arithmetic mean concentration. and the 2006 primary 

and secondary 24-hour NAAOS 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. incorporated by 

reference in Section 243.108 and designated by USEPA and listed 

in List of Designated Methods. incorporated by reference in 

Section 243.108: or 

B) An FEM designated by USEPA and listed in List of Designated 

Methods. incorporated by reference in Section 243.108. 

2) The 2006 primary and secondary annual average NAAOS for PM,.s is met 

when the annual arithmetic mean concentration. as determined in 

accordance with appendix N of 40 CFR 50. incorporated by reference in 

Section 243.108. is less than or equal to 15.0 ug/m3 

3) The 2006 primary and secondary 24-hour NAAOS for PM, 5 is met when 

the 98th percentile 24-hour concentration, as detennined in accordance 

with appendix N of 40 CFR 50. inc01porated by reference in Section 

243.108. is less than or equal to 35 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 StanEiarEis. Tae j3Fimary ambient air E!Hality stanEiarEis fer salfur eKiEies 

measareEI as salrur ElimliEie are: 
Ill 

I) AR allllilal aritl!metie H!eaR eeReeR!ratieR ef go flg/H!" (0.03 J3J3H1); ana, 

2) A H!aKiFRHHI 24 heur eeaeeR!ratiea, net te Be eKeeeEieEI H!ere than eRee 

13eryear, ef3a5 Ftgi.nl(O.l4 J3J3H!). 

B) S eeenEiary StanEiarEI. The seeeREiary aH!BieRt air EjUa!ity staREiarEI fer sulfur eKiEies 

H!easHFeEI as sulfur ElimciEie is a H!aKirauH! 3 heur eeReeR!ratieR net te Be eJceeeEieEI 

H!ere thaR ease 13er year ef 1,300 Fl§ H!~ (0.5 J3J3H!). 

e) MeasuremeRI MetheEI. Fer EleterH!iffiRg eeRfernlaRee with sulfur eJciEie air Ejllality 

staREiarEis, sulfur eKiEies shall Be H!easureEI as sulfur ElieJciEie BY the J3araresaniliae 

H!etheEI EleseriBeEI iR 4 0 CFR 50, apJ3enEiiK A, (iaeerJ3emteEI BY refereaee iR 

SeetieR 24 3 .I og), er B)' aR eEjllivaleat H!etheEI efJ3reef aJ3J3re'<'eEI B)' the AgeRey. 

a) 1971 primary annual average and 24-hour NAAOS for sulfur oxides (as sulfur 

dioxide CSOz)). 

1) The level of the 1971 primmy annual average NAAQS for sulfur oxides is 

0.030 ppm. not to be exceeded in a calendar year. The annual a1ithmetic 

mean must be rounded to three decimal places (fractional pm1s equal to or 

greater than 0.0005 ppm must be rounded up). 

2) The level of the 1971 primary 24-hour NAAQS for sulfur oxides is 0.14 

ppm. not to be exceeded more than once per calendar year. The 24-hour 

averages must be determined from successive non-overlapping 24-hour 

blocks stat1ing 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 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 m·e at least 

75 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 period 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. If less 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. then this must be considered a valid 
112 

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 primary annual average and 24-hourNAAQS for sulfur oxides 

set forth in this subsection (a) remains applicable to all areas 

notwithstanding the promulgation of the 2010 primmy one-hour NAAQS 

for sulfur oxides in subsection (c) of this Section. The Board will delete 

the 1971 primm-y annual average and 24-hour NAAQS for sulfur oxides 

set fmih in this subsection (a) after fulfillment of the conditions recited by 

USEPA in corresponding 40 CFR 50.4(e). 

BOARD NOTE: Co!Tesponding 40 CFR 50.4(e) recites that the 1971 

primary NAAQS 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 NAAQS for sulfur oxides. 

The first type of area is one that USEPA had designated as non-attainment 

for that standard as of the effective date of the 2010 primary one-hour 

NAAQS for the 1971 mimmy NAAQS 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-attainn1ent. See 40 CFR 81.314 (20 1 0). The 

Board is unaware of any USEPA SIP call for any area of Illinois relative 

to the 1971 mimary NAAOS for sulfur oxides. As of December 31, 2012. 

USEP A 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-attainment with the 2010 primary 

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, USEPA 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 USEPA has removed 40 CFR 50.4. the Board 

will remove the standard of this subsection (a) as obsolete. 

b) 1971 secondary three-hour NAAOS for sulfur oxides (as SO:J.,. 

1) The level of the 1971 secondary three-hour NAAQS for sulfur oxides is 

0.5 ppm, not to be exceeded more than once per calendar year. The threehour averages must be detetmined from successive non-overlapping threehour blocks stmiing at midnight each calendar day and must be rounded to 

one decimal place (fractional parts equal to or greater tha11 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 
113 

Section 243 .I 08, 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 three-hour average must be 

based upon hourly data that are at least 75 percent complete in each 

calendar quarter. 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 three-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)(]) of this 

Section, then this must be considered a valid tlu·ee-hour average. In all 

cases. the three-hour block average must be computed as the sum of the 

hourly averages divided by three. 

BOARD NOTE: This subsection (b) is derived from 40 CFR 50.5 (2012). 

c) 2010 primarv one-hour NAAOS for sulfur oxides (as S02). 

I) The level of the 20 I 0 primary one-hour NAAOS for sulfur oxides is 7 5 

ppb, measured in the ambient air as SO,. 

2) The 20 I 0 one-hour primary NAAOS for sulfur oxides is met at an ambient 

air quality monitoring site when the three-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 a FRM based on appendix A-1 or A-2 of 40 CFR 50, 

incorporated by reference in Section 243.108, or by a FEM designated by 

USEPA 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)C5) of this Section 

and the appended Board note. 

(Source: Amended at 3 7 Ill. Reg. ___ , effective _________ .../ 

Section 243.123 Carbon Monoxide 

a1 StaaEiaFEIS. The araeieat air EfHality staaEiarEis fer eareea raeaelliEie are: 

1) A raalliFHUra 8 heur eoaeeatratiea net te ee eJteeeEieEI raere than ease !ler 

year of lG railligrams !ler eueie raeter (9 !l!lra); aaEI, 
114 

2) A maJtimllnl. I hoar eoHeeHtratiofl Hot to ee eJteeeaea more thGF! OF!ee 13er 

year of 4Q milligrams j3er eaeie meter (35 j3j3m). 

13) Measaremeflt Methoa. For Eletermimflg eoHfoF!FlaHee with the eareofl moHoKiae 

air quality staf!aara, SarBOFl mOFlOKiae shallee measmeaey the FlOFlEiiSj3eFsive 

in£·area Sj3eetrometry teeemque as Eleserieea ffi 40 CPR 50, fl<j3j3. C (1982), 38 

Pea. Reg. ?2,391, l'!o;•emeer 25, 1971, orB')" afl eqai'raleflt methoa aj3j3roveaey 

the AgeHey. 

a) The 1971 eight-hour and one-hour primary NAAQS for carbon monoxide are as 

follow: 

I) An eight-hour average concentration of 9 ppm (I 0 mglm\ 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 by a method 

that fulfills either of the following requirements: 

I) An FRM based on appendix C of 40 CFR 50. incorporated by reference in 

Section 243.108. and designated by USEPA and listed in List of 

Designated Methods. incorporated by reference in Section 243.108. or 

2) An FEM designated by USEPA and listed in List of Designated Methods. 

incorporated 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 are 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 summatizing 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 tetms of integers with fractional parts of 0.5 or 

greater rounded up. 

BOARD NOTE: This Section is detived from 40 CFR 50.8 (2012). 

(Source: Amended at 37 IlL Reg. ___ , effective----------' 
115 

Section 243.124 Nitrogen Oxides (Nitrogen Dioxide as Indicator) 

a) Stafleanl. The amlliefll air quality stafleafe fer flitregefl Eliexiee is afl armual 

arithHietie meafl eefleefltratiefl ef lGG mieregrams jler e~>eie meter (G.G§ ll!lffl). 

e) Measm8Ffleflt Methee. Fer Eleteffflifliflg eef!feffflaf!ee with the f!itregefl ei8lliee 

air quality stafleare, flitregefl ei8lliee shall ee meaSHfee ey the eelerimetrie 

methee as Eleserieee ifl3e Fee. Reg. 22,396, J>levefflher 15, 1971, er ey afl 

eEjHivaleflt methee ajljlf8Yee ey the Agefl6)'. 

a) The level of the 1971 primary annual average NAAQS for nitrogen oxides is 53 

ppb. annual average concentration. measured in the ambient air as nitrogen 

dioxide (NOzl. 

b) The level of the 2010 primary one-hourNAAQS for nitrogen oxides is 100 ppb. 

one-hour average concentration. measured in the ambient air as NQ,. 

c) The level of the 1971 secondary annual average NAAQS for nitrogen oxides is 

0.053 ppm (100 1.\glm\ annual arithmetic mean concentration. measured in the 

ambient air as NO,. 

d) The levels of the standards in subsections (a) through (c) of this Section must be 

measured by: 

1) A FRM based on appendix F to 40 CFR 50. incorporated by reference in 

Section 243.108. and designated by US EPA and listed in List of 

Designated Methods. incorporated by reference in Section 243.1 08; or 

2) By a Federal FEM designated by USEPA and listed in List of Designated 

Methods. incOluorated by reference in Section 243.108. 

e) The 1971 primary annual average NAAQS for nih·ogen 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. incorporated by reference in Section 243.108 for the annual standard. 

f) The 2010 one-hour primary NAAQS for nitrogen oxides in subsection (b) of this 

Section is met when the three-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 three decimal places 

(fractional parts equal to or greater than 0.0005 ppm must be rounded up). To 
116 

demonstrate attainment, an annual mean must be based upon hourly data that are 

at least 7 5 percent complete or upon data derived from manual methods that are at 

least 75 percent complete for the scheduled sampling days in each calendar 

quarter. 

BOARD NOTE: This Section is derived from 40 CFR 50.11 (2012). 

(Source: Amended at 37 Ill. Reg. ____ ., effective _________ __, 

Section 243.125 8 IleHF Ozone 

a) Stafldanl The primary afld seeefldary amlliefll air EjHality stafldards for ezefle are 

0.075 p1_3n1 (parts per milliea) Elaily n1aKimHFB:: g BoHr average eeaeeE:tration, 

fl1easured afld determifled ifl aeeerda!'lee with SHeseetiefl (e). 

e) MeasHremefll Methee. Ozefle shallee measHred ey a federal eEjHicvaleflt fl1ethed 

eased efl 4G CFR 5G, appefldiJ< D a!'ld desigflated ifl aeeerda!'lee ·.vith 4G CFR 53 

(ifleeFJ!leratee ey refereflee ifl Seetiefl 243.1G8) er afl eEjHivalefll methed 

desigflated ifl aeeerda!'lee ·.vith 4G CFR 53. The primary afld seee!'ldary ameieflt 

air Efl:lality stanElarEis are met wheE: the average of tHe annHal ~Uith highest Elaily 

maKiflllim 8 heHr &verage ezefle eefleefl!ratiefl is less thafl sf eEjHal te G.G75 ppm, 

as determiflee Hsiflg 4G CFR 5G, appeFldiK P (ifleeFJ!lerated ey refereflee ifl Seetiefl 

243.1G8). 

a) 1979 primary and secondary one-hour NAAOS for ozone. 

1) The level of the 1979 primmy and secondary one-hour NAAQS for ozone 

measured by an FRM based on appendix D to 40 CFR 50. incomorated by 

reference in Section 243.108 and designated by USEP A and listed in List 

of Designated Methods. incomorated by reference in Section 243.108, is 

0.12 ppm (235 u.g!m\ The NAAQS is attained when the expected 

number of days per calendar year with maximum hourly average 

concentrations above 0.12 ppm (235 u.g/m3

) is equal to orless than Las 

determined by appendix H to 40 CFR 50, incmporated by reference in 

Section 243.108. 

2) The 1979 primary and secondary one-hour NAAQS for ozone set forth in 

this subsection (a) will remain applicable to all areas notwithstanding the 

promulgation of the 2008 eight-hour primary and secondary NAAQS for 

ozone set forth in subsection (b) of this Section. USEP A has stated in 

CO!Tesponding 40 CFR 50.9(b) that the one-hour primary and secondary 

NAAQS for ozone 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 

USEP A pursuant to 42 UCS 7407 for the 2008 eight-hour P'imary and 

secondary NAAQS for ozone. USEPA has codified the area designations 

and classifications with respect to the primary and secondary 1997 one-
117 

hour NAAOS and the 2008 primary and secondmy NAAOS for ozone in 

40 CFR 81.314. 

¢ 

BOARD NOTE: This subsection (a) is detived from 40 CFR 50.9 (2012). 

USEP A revoked the 1979 primary and secondary one-hour NAAOS for ozone for 

all m·eas in Illinois effective June 15,2005. See 40 CFR 81.314 (table for onehour NAAOS for ozone, note 3: 70 Fed. Reg. 444 70, 75 (Aug. 3, 2005). 

USEPA's state implementation plan (SIP) regulations, however, provide that the 

State may first apply for modification of the SIP for the 1997 primary and 

secondmy one-hour NAAOS for ozone eight years after the revocation. which is 

on or after June 15,2013. See 40 CFR 51.905(e). Since there is no indication 

that USEPA has approved such a SIP modification. the Board has retained the 

1979 mimary and secondary one-hourNAAOS for ozone of 50 CFR 50.9. 

b) 1997 mimary and secondary eight-hour NAAOS for ozone. 

I) The 1997 hour p1imary and secondary eight-hour NAAOS for ozone, 

measured by a FRM based on appendix D to 40 CFR 50. incmporated by 

reference in Section 243.108 and designated by USEPA and listed in List 

of Designated Methods, incomorated by reference in Section 243.108. is 

0.08 ppm. daily maximum eight-hour average. 

2) The 1997 primary and secondary eight-hour NAAOS for ozone is met at 

an aJUbient air quality monitming site when the average of the annual 

fom1h-highest daily maximum eight-hour average ozone concentration is 

less than or equal to 0.08 ppm. as determined in accordance with appendix 

I to 40 CFR 50. incmporated by reference in Section 243.108. 

3) US EPA has stated in corresponding 40 CFR 50.10(c) that the 1997 

primary and secondary eight-hour NAAOS for ozone set forth in 

subsection (b)(]) of this Section will no longer apply to an area for 

transportation conformity pumoses 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 NAAOS set forth for ozone in 

subsection (c)(]) of this Section. The 1997 primary and secondary eighthour NAAOS for ozone set forth in this subsection (b) will remain 

applicable to all areas for all other pmposes notwithstanding the 2008 

primary and secondary eight-hour NAAOS for ozone set forth in 

subsection (c) of this Section or the USEPA designation of areas for that 

2008 primary and secondary eight-hour NAAOS for ozone. 

BOARD NOTE: USEP A has codified area designations and 

classifications with respect to the 1997 and 2008 mimmy and secondary 

NAAOS for ozone in 40 CFR 81.314. When USEPA has taken action and 

the conditions of subsection (b)(3) have been fulfilled. or USEP A has 

removed 40 CFR 50.9 or 50.10, the Board will remove obsolete 1997 
118 

p1imary and secondary one-hour or eight-hour NAAOS for ozone from 

subsections (a) and (b). 

BOARD NOTE: This subsection (b) is derived from 40 CFR 50.10 (20 12). 

c) 2008 primary and secondary eight-hour NAAOS for ozone. 

1) The 2008 p1imary and secondary eight-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. incorporated by reference in Section 243.108. 

and designated by USEP A and listed in List of Designated Methods. 

incorporated by reference in Section 243.108 or an FEM designated by 

USEPA and listed in List of Designated Methods. incorporated by 

reference in Section 243.108. 

2) The 2008 primary and secondary eight-hour NAAOS for ozone ambient 

air quality standards are met at an ambient air qualitv monitoring site 

when the three-year average of the annual fomth-highest daily maximum 

eight-hour average ozone concentration is less than or equal to 0.075 ppm. 

as detennined in accordance with appendix P to 40 CFR 50. incmporated 

by reference in Section 243.108. 

BOARD NOTE: This subsection (c) is derived from 40 CFR 50.15 (2012). 

(Source: Amended at 37 Ill. Reg. ____ , effective _________ ...J 

Section 243.126 Lead 

a) Staf!aanl. Tlie J3rimary af!a seeef!aary amaieflt air EJ:Hality staf!aaras for leaa af!a 

its eemJ3mmds measurea as elemefllalleaa are G.l § flg;'m~, maJtimum. relliag !flree 

mefllfl average measurea ana aeteFH!med ever a three year J3e1iea. 

a) Measuremelll Me!flea. Fer aeteFH!ifliflg eef!fonnaf!ee witli !fle iHl'!Bieflt air EJ:uality 

staf!aaras fer leaa afla its eeffiJ3SUflas, lead afla its 68ff1J38Uflas sliall ae ff!easurea 

as elefflefllalleaa ay foaeral eEJ:Hivaleflt me!flea aasea efl 4 Q CFR §Q apJ3eflail< G 

afla aesigflatea ID aeeeraaflee ·.vi!fl4G CFR §3, Sf ay afl BEj:tlivalefll ffletflea 

desigflatea ifl aeeeraaf!ee ·.vi!fl4G CFR §3 (ifleSrJ3eratea ay referef!ee ifl Seetiefl 

24 3 .IG8).. CeffiJ3liaflee ·.villi !fle J3rimary ana seeef!aary affiBiefll air EJ:Hality 

staflaaras sliall ae aeteRfliflea ifl aeeeraaflee witli 4 G CFR §Q, apJ3eflaiJ< R 

(ifleSrJ3erated ay reforef!ee ifl Seetiefl243 .1 G8). 

a) 1978 primary and secondary quarterly average NAAOS for lead. 

1) The 1978 primary and secondary qumterly average NAAOS for lead and 

its compounds. measured as elemental lead by an FRM based on appendix 

G to 40 CFR 50. incomorated by reference in Section 243.108. and 
119 

designated by USEP A and listed in List of Designated Methods. 

incomorated 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. is 1.5 micrograms per cubic meter. 

maximum arithmetic mean averaged over a calendar quarter. 

2) The 1978 primary and secondary quaJierly average NAAOS for lead set 

fmih in this subsection will remain applicable to all areas notwithstanding 

the 2008 primary and secondary quarterly average NAAOS for lead in 

subsection (b) of this Section. The 1978 primmy and secondary quaJierly 

average NAAOS 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 NAAOS for lead set forth in subsection 

(b) of this Section: except that for areas designated nonattainment for the 

1978 primary and secondary quarterly average NAAOS for lead set forth 

in this subsection (a) as of January 12.2009. the 1978 PJimmy and 

secondary NAAOS for lead set forth in this subsection (a) will apply until 

USEPA has approved an implementation plan for that m·ea pursuant to 42 

USC 7 514 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 corr-esponding 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 

Fed. Reg. 66964 (Nov. 12. 2008). USEP A designated Granite City as 

nonattainment with the 2008 primary and secondaJY three-month average 

NAAOS for lead in 20 I 0 and an area of Chicago in 20 II. USEP A 

designated all other areas of lilinois for the 2008 primary and secondary 

three-month average NAAOS 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 NAAOS for lead. 

I) The 2008 primary and secondary three-month average NAAOS for lead 

and its compounds is 0.15 ug/m3

• mithmetic mean concentration over a 

three-month period. measured in the ambient air as lead by either of the 

following: 
120 

A) An FRM based on Appendix G of 40 CFR 50, incorporated by 

reference in Section 243.108 and designated by USEPA and listed 

in List of Designated Methods, incorporated by reference in 

Section 243.108 or; 

B) An FEM designated by USEPA and listed in List of Designated 

Methods. incmporated by reference in Section 243.108. 

2) The 2008 primary and secondary three-month average NAAQS for lead 

are met when the maximum arithmetic three-month mean concentration 

for a three-year pe1iod. as determined in accordance with Appendix R of 

40 CFR 50, incorporated by reference in Section 243.108, is less than or 

equal to 0.15 ug/m3 

BOARD NOTE: This subsection (b) is derived from 40 CFR 50.16 (2012). 

(Source: Amended at 37 Ill. Reg. ___ , effective----------' 

Section 243.APPENDIX A Rule into Section Table (Repealed) 

Appendix A 

Rule into Section Table 

8ECTirnl 

243.102 

243.103 

243.104 

,'<!l!l e;uiiK C 

243.106 

243.107 

243.121 

243.122 

RBflealee 

243.123 

243.124 

243.125 

243.126 

(Source: Repealed at 3 7 Ill. Reg. ---, effective ________ _J 
121 

Section 243.APPENDIX B Section into Rule Table (Repealed) 

AppendixB 

Section into Rule Table 

SEC Tim! 

243.101 

243.102 J\H. 

243.103 ~ 

243.104 J03 

243.109 ~ 

243.107 :;oe 

243.121 J07 

243.122 ~ 

243.123 M*l 

?43.124 *+ 

243.12§ ~ 

243.129 ~ 

(Source: Repealed at 37 Ill. Reg. , effective----------' 

Section 243.APPENDIX C Past Compliance Dates (Repealed) 

Appendix C 

Past Compliance Dates 

EKeejlt as ethe1wise aeted, eemjlliaaee wi-th this Pmt was reEjtlired fuae 29, 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 

NAAQS 

(Level) 

Regulatory Citations 

2006 24-hour PMz s 

(35 ug/m3

) 

Section 243.120(c)(l) 

40 CFR 50.13(a) 

71 Fed. Reg. 61144 (Oct. 

17. 2006) 

Air quality 

data collected Event flagging & 

for calendar initial desc1iption 

year deadline 

2004-2006 October 1. 2007 

Detailed 

documentation 

submission deadline 

April 15, 2008 
122 

2008 eight-hour ozone 2005-2007 June 18, 2009 June 18, 2009 

(0.075 ppm) 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 guarter of the calendar guarter 

73 Fed. Reg. 16436 (Mar. in which the event in which the event 

27, 2008} occurred or February occurred or February 

5, 2010, whichever 5. 2010. whichever 

date occurred first date occurred first 

2010 one-hour nitrogen 2008 July 1. 2010 Januaey 22. 2011 

oxides (as NO;U 2009 July 1. 2010 Januat:y 22, 2011 

(100 ppb} 2010 Aprill, 2011 July 1. 2010 

Section 243.124(b} 

40 CFR 50.ll(b} 

75 Fed. Reg. 6474 (Feb. 9. 

2010} 

2010 one-hour sulfur 2008 October 1. 2010 June 1, 2011 

oxides (as SO,} 2009 October 1. 2010 June 1. 2011 

(75 ppb} 2010 June 1. 2011 June 1,2011 

Section 243.122(c}(l} 2011 60 days after the end 60 days after the end 

40 CFR 17(a} of the calendar gua1ter of the calendar guarter 

75 Fed. Reg. 35520 (June in which the event in which the event 

22. 2010} occuned or March 31. occmTed or March 31. 

2012. whichever date 2012. whichever date 

OCCUlTed first occured first 

BOARD NOTE: Derived from table 1 to 40 CFR 50.14(c} (2012}. USEPA noted that the 

infmmation in this table of revised deadlines only applies to data that USEPA will use to 

establish the final initial designations for new or revised NAAQS. USEPA stated that the 

general schedule in this table applies for all other pumoses. most notably. for data that USEP A 

will use for redesignations to attainment. Corresponding table l to 40 CFR 50.14(c}(2} cites the 

2010 one-hour NAAQS for nitrogen oxides as "80-100 PPB, fmallevel TBD" and the 2010 onehour NAAOS for sulfur oxides as "80-100 PPB, final level TBD." The adopted 2010 one-hour 

NAAQS for NOx at 40 CFR 50.11W is 100 ppb and the adopted 2010 one-hourNAAQS for SO, 

is 75 ppb. The Board has used the actual NAAQS for these contaminants in this Table A. 

Fmther. conesponding table 1 to 40 CFR 50.14(c} includes endnotes "a" and "b" indicate 

whether dates for N02 and S02 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. 
123 

I, John T. The!Tiault, Assistant Clerk of the illinois Pollution Control Board, ce1tify that the 

Board adopted the above opinion and order on May 16, 2012, by a vote of 5-0. 

John T. The!Tiault, Assistant Clerk Illinois 

Pollution Control Board