PM2.5 Air Quality Data Update 

2006-2008 Design Values 

The following is a brief summary of EPA's air quality update for PM2.5 based on ambient 

monitoring data for the three-year period, 2006-2008. During this three-year period: 

• Fifteen of the original 39 areas designated nonattainment for the PM2.5 NAAQS in April, 

2005 (using 2001-2003 data) failed to meet the annual PM2.5 NAAQS in 2006-2008. 

Seventeen of the original 39 nonattainment areas met the annual NAAQS in 2006-2008. 

Seven areas have insufficient data to allow a determination of compliance with respect to the 

annual PM2.5 NAAQS in 2006-2008; in each of these seven areas, one or more sites for 

which compliance cannot be determined for 2006-2008 clearly violated the NAAQS in a 

previous period (e.g., for 2005-2007). (Table 1a). 

• Thirty-one areas were designated nonattainment for the 24-hour PM2.5 NAAQS in 

September, 2008. Twenty-eight of these 31 areas failed to meet the NAAQS with 2006-

2008 data. The other three areas are shown to have incomplete data with respect to the 24-

hour PM2.5 NAAQS; in each of these three areas, one or more sites for which compliance 

cannot be determined for 2006-2008 clearly violated the NAAQS in a previous period (e.g., 

for 2005-2007). (Table 1b). 

• Four counties outside of existing (previous and new) PM2.5 nonattainment areas violated one 

or both PM2.5 NAAQS in 2005-2007. (Table 2). 

o Two counties, outside of existing nonattainment areas, did not meet the PM2.5 annual 

NAAQS. 

o Three counties, outside of existing nonattainment areas, did not meet the PM2.5 24-

hour NAAQS. (One county violated both the annual and the 24-hour NAAQS with 

2006-2008 data.) 

o In some of these cases, EPA is still reviewing state requests for exclusion of data 

affected by exceptional events. The outcome of this review may change these 

findings. 

In 1997, EPA established the PM2.5 NAAQS for the protection of public health. 

The annual standard was set at a level of 15.0 micrograms per cubic meter (μg/m3) and the 24-hour 

standard was set at a level of 65 μg/m3. In October 2006, the 24-hour PM2.5 NAAQS was 

strengthened to 35 μg/m3

. 

Air quality data from EPA’s Air Quality System (AQS) were used to calculate PM2.5 design 

values. The specific calculations are explained in footnotes to the tables. Most of the data used for 

these calculations were obtained from AQS on July 7, 2009; in some isolated situations, site data 

were re-extracted at later dates to encompass subsequent AQS changes. Detailed 2006-2008 

information (plus information for previous 3-year periods from 1999-2001) for all PM2.5 FRM/FEM 

sites are available in the downloadable spreadsheet file. 

For information concerning these data and/or calculations, contact: 

Mark Schmidt 

U.S. Environmental Protection Agency 

Air Quality Trends and Analysis Group (C304-01) 

Research Triangle Park, NC 27711 

(919) 541-2416, (919) 541-3613 (FAX) 

Schmidt.mark@epa.gov
Table 1a. 2006-2008 PM2.5 annual standard design values for areas previously designated nonattainment 

for the 1997 NAAQS 

Designated Nonattainment Area State

EPA 

Region

Designation 

Status 1

2006-2008 Annual 

Design Value 2, 3

Met Annual NAAQS 

2006-2008? 2, 3

Atlanta GA 4 Nonattainment 15.2 no Baltimore MD 3 Nonattainment 14.0 yes Birmingham AL 4 Nonattainment 17.3 no Canton-Masillon OH 5 Nonattainment see footnote 4 see footnote 4Charleston WV 3 Nonattainment 15.4 no Chattanooga 

TN-GAAL 4 Nonattainment see footnote 4 see footnote 4

Chicago-Gary-Lake County IL-IN 5 Nonattainment see footnote 4 see footnote 4Cincinnati-Hamilton 

OH-KYIN 4, 5 Nonattainment 15.7 no 

Cleveland-Akron-Lorain OH 5 Nonattainment 15.1 no Columbus OH 5 Nonattainment 13.7 yes Dayton-Springfield OH 5 Nonattainment 14.2 yes Detroit-Ann Arbor MI 5 Nonattainment 15.4 no Evansville IN 5 Nonattainment 13.7 yes Floyd County GA 4 Nonattainment see footnote 4 see footnote 4Greensboro-Winston Salem-High Point NC 4 Nonattainment 14.5 yes Harrisburg-Lebanon-Carlisle PA 3 Nonattainment 13.8 yes Hickory-Morganton-Lenoir NC 4 Nonattainment 14.2 yes Huntington-Ashland 

WV-KYOH 3, 4, 5 Nonattainment 15.2 no 

Indianapolis IN 5 Nonattainment 14.7 yes Johnstown PA 3 Nonattainment 14.4 yes Knoxville TN 4 Nonattainment see footnote 4 see footnote 4Lancaster PA 3 Nonattainment 14.5 yes Libby MT 8 Nonattainment 13.7 yes Liberty-Clairton PA 3 Nonattainment 18.3 no Los Angeles-South Coast Air Basin CA 9 Nonattainment 19.7 no Louisville KY-IN 4, 5 Nonattainment 15.3 no 
Table 1a. 2006-2008 PM2.5 annual standard design values for areas previously designated nonattainment 

for the 1997 NAAQS 

Designated Nonattainment Area State

EPA 

Region

Designation 

Status 1

2006-2008 Annual 

Design Value 2, 3

Met Annual NAAQS 

2006-2008? 2, 3

Macon GA 4 Nonattainment 15.1 no Martinsburg, WV-Hagerstown MD 3 Nonattainment 14.9 yes New York-N.New Jersey-Long Island 

NY-NJCT 1, 2 Nonattainment see footnote 4 see footnote 4

Parkersburg-Marietta WV-OH 3, 5 Nonattainment 14.6 yes Philadelphia-Wilmington 

PA-NJDE 2, 3 Nonattainment see footnote 4 see footnote 4

Pittsburgh-Beaver Valley PA 3 Nonattainment 15.2 no Reading PA 3 Nonattainment 13.6 yes San Joaquin Valley CA 9 Nonattainment 21.5 no St. Louis MO-IL 5, 7 Nonattainment 15.7 no Steubenville-Weirton OH-WV 3, 5 Nonattainment 15.4 no Washington 

DC-MDVA 3 Nonattainment 13.1 yes 

Wheeling WV-OH 3, 5 Nonattainment 14.2 yes York PA 3 Nonattainment 14.6 yes 1. Area designation status as of August 1, 2009. 2. The annual standard design values shown here are calculated in accordance with 40 CFR Part 50, Appendix N (2006). The annual standard design value (i.e., the 3-year average annual mean concentration) is computed at each site by averaging the daily FRM 

samples taken each quarter, averaging these quarterly averages to obtain an annual average, and then averaging the three annual

averages. (Note that special rules apply if an area has been approved for spatial averaging.) The NAAQS level for the annual standaris 15.0 micrograms per cubic meter (μg/m3). In general, EPA regulations require at least 75% data capture in each quarter of a 

consecutive 3-year period in order for a design value to be valid. However, if an annual mean (or 3-year annual design value) is over 

the level of the standard, less data (i.e., 11 samples per quarter for the corresponding 4 quarters) are sufficient to deem that mean validFurther, EPA regulations and guidance permit data substitution under certain circumstances in order to to consider design values as 

valid that otherwise would be considered incomplete. The information presented in this update is based on data after applying the 

substitution protocols. 
3. Data that have been flagged for exceptional events, for which documentation has been submitted and approved by the EPA (AQS

concurrence field set to ‘Y’), if any, were excluded from the design value calculations. In several situations, submitted documentation 

is still under review and as such, revisions to design values are possible. The EPA has approved exclusion of certain flagged 

exceptional event data for the 24-hour NAAQS (based on reviews of supporting documentation submitted by the applicable monitorinagencies), but the EPA has not made a final determination on the exclusion of such data with regards to the annual standard. In this report, these data have been excluded from the annual standard design values (and associated statistical components); hence, the stated annual standard design values (and related statistics) may actually be understated and may later be revised upwards. 

4. One or more previously violating sites (e.g., for 2005-2007) in this area do not have valid 2006-2008 annual design values (i.e., those meeting NAAQS completeness criteria). As such, a 2006-2008 area-level design value is not shown, even in situations where there are additional sites in the area with valid/complete ones, because the highest of those might not represent actual maximum population exposure in the area. The 2006-2008 site listing included in the Excel version of this file show 2006-2008 design values foeach site. 
Table 1b. 2006-2008 PM2.5 24-hour standard design values for areas designated nonattainment for the 

2006 NAAQS on July 31, 2009. 

Designated Nonattainment Area 1 State

EPA 

Region

Designation 

Status 1

2006-2008 24-hr Design 

Value 2, 3

Met 24-hour 

NAAQS (2006 CFR) 

in 2006-2008? 2, 3

Allentown PA 3 Nonattainment 36 no Birmingham AL 4 Nonattainment 39 no Canton-Massillon OH 5 Nonattainment see footnote 4 see footnote 4Charleston WV 3 Nonattainment 36 no Chico CA 9 Nonattainment 69 no Cleveland-Akron-Lorain OH 5 Nonattainment 38 no Detroit-Ann Arbor MI 5 Nonattainment 37 no Fairbanks AK 10 Nonattainment 41 no Harrisburg-Lebanon-Carlisle PA 3 Nonattainment 36 no Imperial County CA 9 Nonattainment 36 noJohnstown PA 3 Nonattainment see footnote 4 see footnote 4Klamath Falls OR 10 Nonattainment 46 no Knoxville-Sevierville-La Follette TN 4 Nonattainment see footnote 4 see footnote 4Lancaster PA 3 Nonattainment 37 no Liberty-Clairton PA 3 Nonattainment 53 no Logan UT-ID 8, 10 Nonattainment 36 no Los Angeles-South Coast Air Basin CA 9 Nonattainment 49 no Milwaukee-Racine WI 5 Nonattainment 37 no New York-N. New Jersey-Long Island 

NY-NJCT 1, 2 Nonattainment 38 no 

Nogales AZ 9 Nonattainment 40 no 

Oakridge OR 10 Nonattainment 40 no Philadelphia-Wilmington PA-NJ- DE 2, 3 Nonattainment 36 no 

Pittsburgh-Beaver Valley PA 3 Nonattainment 36 no Provo UT 8 Nonattainment 44 no Sacramento CA 9 Nonattainment 56 no Salt Lake City UT 8 Nonattainment 48 no San Francisco Bay Area CA 9 Nonattainment 36 no San Joaquin Valley CA 9 Nonattainment 70 no 
Table 1b. 2006-2008 PM2.5 24-hour standard design values for areas designated nonattainment for the 

2006 NAAQS on July 31, 2009. 

Designated Nonattainment Area 1 State

EPA 

Region

Designation 

Status 1

2006-2008 24-hr Design 

Value 2, 3

Met 24-hour 

NAAQS (2006 CFR) 

in 2006-2008? 2, 3

Seattle-Tacoma WA 10 Nonattainment 44 no Steubenville-Weirton OH-WV 3, 5 Nonattainment 41 no Yuba City-Marysville CA 9 Nonattainment 47 no 1. A Federal Register notice regarding 24-hour PM2.5 nonattainment designations based primarily on 2005-2007 design values wassigned by the EPA Administrator Steven Johnson in December 2008 but never published in the Federal Register. The areas listed in this table were designated nonattainment for the 2006 NAAQS by Administrator Lisa Jackson in 2009. 2. The 24-hour standard design values shown here are calculated in accordance with 40 CFR Part 50, Appendix N (2006, ammended 2007). The 24-hour (or 'daily') standard design value (i.e., the 3-year average 98th percentile) is computed at each site by determining the 98th percentile of the daily FRM samples taken in a given year for each of the three years, and then averaging these three numbers. The NAAQS level for the 24-hour standard is 35 micrograms per cubic meter (μg/m3). In general, EPA regulations require at least 75% data capture in each quarter of a consecutive 3-year period in order for a design value to be valid. However, if an annual 98th percentile (or 3-year 24-hour design value) is over the level of the standard, less data (i.e., only 1 sample in that year) is 

sufficient to make that 98th percentile valid. Further, EPA regulations and guidance permit data substitution under certain circumstances in order to consider design values as valid that otherwise would be considered incomplete. The information presented in this update is based on data after applying the substitution protocols. 

3. Data that have been flagged for exceptional events, for which documentation has been submitted and approved by the EPA (AQS

concurrence field set to ‘Y’), if any, were excluded from the design value calculations. In several situations, submitted documentation is still under review and as such, revisions to design values are possible. 

4. One or more previously violating sites (i.e., for 2005-2007) in this area do not have valid 2006-2008 24-hour design values (i.e., those meeting NAAQS completeness criteria). As such, a 2006-2008 area-level design value is not shown, even in situations where there are additional sites in the area with valid/complete ones, because the highest of those might not represent actual maximum population exposure in the area. The 2006-2008 site listing included in the Excel version of this file shows 2006-2008 design values for each site. 
Table 2. 2006-2008 PM2.5 design values for violating counties not part of a designated nonattainment are

State County CBSA

EPA 

Region

Annual 

Design Value 

1, 3

Met annual 

NAAQS in 

2006-2008? 1, 

3

24-hr Design 

Value 2, 3

Met 24-

NAAQ

2006-200

Arizona Pinal Phoenix-Mesa-Scottsdale, AZ 9 21.6 no 48 no California Plumas 9 12.6 yes 49 no California Shasta Redding, CA 9 9.6 yes 48 no Texas Harris 

Houston-Sugar Land-Baytown, TX 6 15.2 no 30 yes 

1. The annual standard design values shown here are calculated in accordance with 40 CFR Part 50, Appendix N (2006). The annual value (i.e., 3-year average annual mean concentration) is computed at each site by averaging the daily FRM samples taken each quarte

quarterly averages to obtain an annual average, and then averaging the three annual averages. (Note that special rules apply if an area 

for spatial averaging.) The NAAQS level for the annual standard is 15.0 micrograms per cubic meter (μg/m3). In general, EPA regulleast 75% data capture in each quarter of a consecutive 3-year period in order for a design value to be valid. However, if an annual me

annual design value) is over the level of the standard, less data (i.e., 11 samples per quarter for the corresponding 4 quarters) are sufficmean valid. Further, EPA regulations and guidance permit data substitution under certain circumstances in order to to consider design 

that otherwise would be considered incomplete. The information presented in this update is based on data after applying the substituti

2. The 24-hour standard design values shown here are calculated in accordance with 40 CFR Part 50, Appendix N (2006, ammended hour (or 'daily') standard design value (i.e., the 3-year average 98th percentile) is computed at each site by determining the 98th perceFRM samples taken in a given year for each of the three years, and then averaging these three numbers. The NAAQS level for the 24

35 micrograms per cubic meter (μg/m3). In general, EPA regulations require at least 75% data capture in each quarter of a consecutivorder for a design value to be valid. However, if an annual 98th percentile (or 3-year 24-hour design value) is over the level of the stan

only 1 sample in that year) is sufficient to make that 98th percentile valid. Further, EPA regulations and guidance permit data substitcircumstances in order to consider design values as valid that otherwise would be considered incomplete. The information presented ibased on data after applying the substitution protocols. 

3. Data that have been flagged for exceptional events, for which documentation has been submitted and approved by the EPA (AQS c

set to ‘Y’), if any, were excluded from the design value calculations. In several situations, submitted documentation is still under revrevisions to design values are possible. The EPA has approved exclusion of certain flagged exceptional event data for the 24-hour NAreviews of supporting documentation submitted by the applicable monitoring agencies), but the EPA has not made a final determinatioof such data with regards to the annual standard. In this report, these data have been excluded from the annual standard design values statistical components); hence, the stated annual standard design values (and related statistics) may actually be understated and may la

upwards. 

Data Source: U.S. EPA’s Air Quality System (AQS) as of July 7, 2009 (and later dates in isolated situations).