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Additional Background Information on EPA’s Clean Data Policy 

In April 2007, EPA issued its PM2.5 Implementation Rule for the 1997 PM2.5 standard. 

72 FR 26586; (April 25, 2007). In March, 2012, EPA published implementation guidance for 

the 2006 PM2.5 standard. See Memorandum from Stephen D. Page, Director, Office of Air 

Quality Planning and Standards, “Implementation Guidance for the 2006 24-Hour Final Particle 

(PM2.5) National Ambient Air Quality Standards (NAAQS)" (March 2, 2012). In that guidance, 

EPA stated its view “that the overall framework and policy approach of the 2007 PM2.5

Implementation Rule continues to provide effective and appropriate guidance on the EPA’ s 

interpretation of the general statutory requirements that states should address in their SIPs. In 

general, the EPA believes that the interpretations of the statute in the framework of the 2007 

PM2.5 Implementation Rule are relevant to the statutory requirements for the 2006 24-hour PM2.5

NAAQS ...." Id., page 1. With respect to the statutory provisions applicable to 2006 PM2.5

implementation, the guidance emphasized that “EPA outlined its interpretation of many of these 

provisions in the 2007 PM2.5 Implementation Rule. In addition to regulatory provisions, the EPA 

provided substantial general guidance for attainment plans for PM2.5 in the preamble to the final 

the [sic] 2007 PM2.5 Implementation Rule.” Id., page 2. In keeping with the principles set forth 

in the guidance, and with respect to the effect of a determination of attainment for the 2006 PM2.5

standard, EPA is applying the same interpretation with respect to the implications of clean data 

determinations that it set forth in the preamble to the 1997 PM2.5 standard and in the regulation 

that embodies this interpretation. 40 CFR 51.1004(c).1

 EPA has long applied this interpretation 

in regulations and individual rulemakings for the 1-hour ozone and 1997 8-hour ozone standards, 

the PM-10 standard, and the lead standard. 

 

1

 While EPA recognizes that 40 CFR 51.1004(c) does not itself expressly apply to the 2006 PM2.5 standard, the 

statutory interpretation that it embodies is identical and is applicable to both the 1997 and 2006 PM2.5standards. 
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History and Basis of EPA’s Clean Data Policy 

Following enactment of the CAA Amendments of 1990, EPA promulgated its 

interpretation of the requirements for implementing the NAAQS in the general preamble for the 

Implementation of Title I of the CAA Amendments of 1990 (General Preamble) 57 FR 13498, 

13564 (April 16, 1992). In 1995, based on the interpretation of CAA sections 171 and 172, and 

section 182 in the General Preamble, EPA set forth what has become known as its “Clean Data 

Policy” for the 1-hour ozone NAAQS. See Memorandum from John S. Seitz, Director, Office of

Air Quality Planning and Standards, “Reasonable Further Progress, Attainment Demonstration, 

and Related Requirements for Ozone Nonattainment Areas Meeting the Ozone National Ambient 

Air Quality Standard” (May 10, 1995). In 2004, EPA indicated its intention to extend the Clean 

Data Policy to the PM2.5 NAAQS. See Memorandum from Steve Page, Director, EPA Office of 

Air Quality Planning and Standards, “Clean Data Policy for the Fine Particle National Ambient 

Air Quality Standards” (December 14, 2004). 

Since 1995, EPA has applied its interpretation under the Clean Data Policy in many 

rulemakings, suspending certain attainment-related planning requirements for individual areas, 

based on a determination of attainment. See 60 FR 36723 (July 18, 1995) (Salt Lake and Davis 

Counties, Utah, 1-hour ozone); 61 FR 20458 (May 7, 1996) (Cleveland-Akron-Lorain, Ohio, 1-

hour ozone); 61 FR 31832 (June 21, 1996) (Grand Rapids, Michigan, 1-hour ozone); 65 FR 

37879 (June 19, 2000) (Cincinnati-Hamilton, Ohio-Kentucky, 1-hour ozone); 66 FR 53094 

(October 19, 2001) (Pittsburgh-Beaver Valley, Pennsylvania, 1-hour ozone); 68 FR 25418 (May 

12, 2003) (St. Louis, Missouri-Illinois, 1-hour ozone); 69 FR 21717 (April 22, 2004) (San 

Francisco Bay Area, California, 1-hour ozone), 75 FR 6570 (February 10, 2010) (Baton Rouge, 

Louisiana, 1-hour ozone), 75 FR 27944 (May 19, 2010) (Coso Junction, California, PM10). 
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EPA also incorporated its interpretation under the Clean Data Policy in several 

implementation rules. See Clean Air Fine Particle Implementation Rule, 72 FR 20586 (April 25, 

2007); Final Rule To Implement the 8-Hour Ozone National Ambient Air Quality Standard — 

Phase 2, 70 FR 71612 (November 29, 2005). The Court of Appeals for the District of Columbia 

Circuit (D.C. Circuit) upheld EPA’s rule embodying the Clean Data Policy for the 1997 8-hour 

ozone standard. NRDC v. EPA, 571 F.3d 1245 (D.C. Cir. 2009). Other courts have reviewed 

and considered individual rulemakings applying EPA’s Clean Data Policy, and have consistently 

upheld them in every case. Sierra Club v. EPA, 99 F. 3d 1551 (10th Cir. 1996); Sierra Club v.

EPA, 375 F. 3d 537 (7th Cir. 2004); Our Children's Earth Foundation v. EPA, No. 04-73032 

(9th Cir. June 28, 2005 (Memorandum Opinion)), Latino Issues Forum v. EPA, Nos. 06-75831 

and 08-71238 (9th Cir. March 2, 2009 (Memorandum Opinion)). 

EPA sets forth below a brief explanation of the statutory interpretations in the Clean Data 

Policy. EPA also incorporates the discussions of its interpretation set forth in prior rulemakings, 

including the 1997 PM2.5 implementation rulemaking. See 72 FR 20586, at 20603-20605 (April 

25, 2007). See also 75 FR 31288 (June 3, 2010) (Providence, Rhode Island, 1997 8-hour ozone), 

75 FR 62470 (October 12, 2010) (Knoxville, Tennessee, 1997 8-hour ozone), 75 FR 53219 

(August 31, 2010) (Greater Connecticut Area, 1997 8-hour ozone), 75 FR 54778 (September 9, 

2010) (Baton Rouge, Louisiana, 1997 8-hour ozone), 75 FR 64949 (October 21, 2010) 

(Providence, Rhode Island, 1997 8-hour ozone), 76 FR 11080 (March 1, 2011) (MilwaukeeRacine and Sheboygan Areas, Wisconsin, 1997 8-hour ozone), 76 FR 31273 (May 31, 2011) 

(Pittsburgh-Beaver Valley, Pennsylvania, 1997 8-hour ozone), 76 FR 33647 (June 9, 2011) (St. 

Louis, Missouri-Illinois, 1997 8-hour ozone), 76 FR 7145 (November 15, 2011) (CharlotteGastonia-Rock Hill, North Carolina-South Carolina, 1997 8-hour ozone), 77 FR 31496 (May 29, 
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2012) (Boston-Lawrence-Worchester, Massachusetts, 1997 8-hour ozone). See also, 75 FR 56 

(January 4, 2010) (Greensboro-Winston-Salem-High Point, North Carolina, 1997 PM2.5), 75 FR 

230 (January 5, 2010) (Hickory-Morganton-Lenoir, North Carolina, 1997 PM2.5), 76 FR 12860 

(March 9, 2011) (Louisville, Kentucky-Indiana, 1997 PM2.5), 76 FR 1850 (April 5, 2011) (Rome, 

Georgia, 1997 PM2.5), 76 FR 31239 (May 31, 2011) (Chattanooga, Tennessee-Georgia-Alabama, 

1997 PM2.5), 76 FR 31858 (June 2, 2011) (Macon, Georgia, 1997 PM2.5), 76 FR 36873 (June 23, 

2011) (Atlanta, Georgia, 1997 PM2.5), 76 FR 38023 (June 29, 2011) (Birmingham, Alabama, 

1997 PM2.5), 76 FR 5542 (September 7, 2011) (Huntington-Ashland, West Virginia-KentuckyOhio, 1997 PM2.5), 76 FR 60373 (September 29, 2011) (Cincinnati, Ohio-Kentucky-Indiana, 

1997 PM2.5), 77 FR 18922 (March 29, 2012) (Harrisburg-Lebanon-Carlisle-York, Allentown, 

Johnstown and Lancaster, Pennsylvania, 1997 PM2.5). 

The Clean Data Policy represents EPA’s interpretation that certain requirements of 

subpart 1 of part D of the Act are by their terms not applicable to areas that are currently 

attaining the NAAQS.2

 As explained below, the specific requirements that are inapplicable to an 

area attaining the standard are the requirements to submit a SIP that provides for: attainment of 

the NAAQS; implementation of all reasonably available control measures; reasonable further 

progress (RFP); and implementation of contingency measures for failure to meet deadlines for 

RFP and attainment. 

CAA section 172(c)(1), the requirement for an attainment demonstration, provides in 

relevant part that SIPs “shall provide for attainment of the [NAAQS].” EPA has interpreted this 

requirement as not applying to areas that have already attained the standard. If an area has 

attained the standard, there is no need to submit a plan demonstrating how the area will reach 

 

2

 This discussion refers to subpart 1 because subpart 1 contains the requirements relating to attainment of the 2006 

PM2.5 NAAQS.
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attainment. In the General Preamble (57 FR 13564), EPA stated that no other measures to 

provide for attainment would be needed by areas seeking redesignation to attainment since 

“attainment will have been reached.” See also Memorandum from John Calcagni, “Procedures 

for Processing Requests to Redesignate Areas to Attainment,” (September 4, 1992), at page 6. 

A component of the attainment plan specified under section 172(c)(1) is the requirement 

to provide for “the implementation of all reasonably available control measures as expeditiously 

as practicable” (RACM). Since RACM is an element of the attainment demonstration, see 

General Preamble (57 FR 13560), for the same reason the attainment demonstration no longer 

applies by its own terms, RACM also no longer applies to areas that EPA has determined have 

clean air. Furthermore, EPA has consistently interpreted this provision to require only 

implementation of such potential RACM measures that could advance attainment.3

 Thus, where 

an area is already attaining the standard, no additional RACM measures are required. EPA’s 

interpretation that the statute requires only implementation of the RACM measures that would 

advance attainment was upheld by the United States Court of Appeals for the Fifth Circuit 

(Sierra Club v. EPA, 314 F.3d 735, 743–745, 5th Cir. 2002) and by the United States Court of 

Appeals for the D.C. Circuit (Sierra Club v. EPA, 294 F. 3d 155, 162–163, D.C. Cir. 2002). See 

also the final rulemakings for Pittsburgh-Beaver Valley, Pennsylvania, 66 FR 53096 (October 

19, 2001) and St. Louis, Missouri-Illinois, 68 FR 25418 (May 12, 2003). 

CAA section 172(c)(2) provides that state implementation plan (SIP) provisions in 

nonattainment areas must require “reasonable further progress.” The term “reasonable further 

progress” is defined in section 171(1) as “such annual incremental reductions in emissions of the 

relevant air pollutant as are required by this part or may reasonably be required by the 

 

3 This interpretation was adopted in the General Preamble, see 57 FR 13498, and has been upheld as applied to the

Clean Data Policy, as well as to nonattainment SIP submissions. See NRDC v. EPA, 571 F.3d 1245 (D.C. Cir. 

2009); Sierra Club v. EPA, 294 F.3d 155 (D.C. Cir. 2002).
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Administrator for the purpose of ensuring attainment of the applicable NAAQS by the applicable 

date.” Thus, by definition, the “reasonable further progress” provision under subpart 1 requires 

only such reductions in emissions as are necessary to attain the NAAQS. If an area has attained 

the NAAQS, the purpose of the RFP requirement has been fulfilled, and since the area has 

already attained, showing that the State will make RFP towards attainment “[has] no meaning at 

that point.” General Preamble, 57 FR 13498, 13564 (April 16, 1992). 

CAA section 172(c)(9) provides that SIPs in nonattainment areas “shall provide for the 

implementation of specific measures to be undertaken if the area fails to make reasonable further 

progress, or to attain the [NAAQS] by the attainment date applicable under this part. Such 

measures shall be included in the plan revision as contingency measures to take effect in any 

such case without further action by the State or [EPA].” This contingency measure requirement 

is inextricably tied to the reasonable further progress and attainment demonstration requirements. 

Contingency measures are implemented if reasonable further progress targets are not achieved, 

or if attainment is not realized by the attainment date. Where an area has already achieved 

attainment, it has no need to rely on contingency measures to come into attainment or to make 

further progress to attainment. As EPA stated in the General Preamble: 

“The section 172(c)(9) requirements for contingency measures are directed at ensuring RFP and 

attainment by the applicable date.” See 57 FR 13564. Thus these requirements no longer apply 

when an area has attained the standard. 

It is important to note that should an area attain the 2006 PM2.5 standard based on three 

years of data, its obligation to submit an attainment demonstration and related planning 

submissions is suspended only for so long as the area continues to attain the standard. If EPA 

subsequently determines, after notice-and-comment rulemaking, that the area has violated the 
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NAAQS, the requirements for the State to submit a SIP to meet the previously suspended 

requirements would be reinstated. It is likewise important to note that the area remains 

designated nonattainment pending a further redesignation action.