DATE: 	1 December 2016

SUBJECT: 	Technical Support Document Regarding PM2.5 Monitoring Data  -  Determinations of Attainment by the Attainment Date, Determinations of Failure to Attain by the Attainment Date and Reclassifications for Certain Nonattainment Areas for the 2006 24-Hour Fine Particulate Matter National Ambient Air Quality Standards


FROM:	Leigh Herrington, Environmental Protection Specialist
      
TO:		Air and Radiation Docket EPA-HQ-OAR-2016-0515

THRU: 	Megan Brachtl, Group Leader
            State and Local Programs Group
            
This document provides a technical review of the air quality monitoring data used to support the
EPA's proposed determinations for 11 nonattainment areas classified as "Moderate" for the 2006 24-hour fine particle pollution air quality standards. These areas were designated on December 14, 2009 and were required to meet the standards by December 31, 2015 (74 FR 58688). The areas included in this action are listed below in "List 1: Certain 2006 24-hour PM2.5 NAAQS Moderate Nonattainment Areas."

List 1: Certain 2006 24-hour PM2.5 NAAQS Moderate Nonattainment Areas 
 Chico, CA
 Fairbanks, AK
 Imperial County, CA
 Knoxville-Sevierville-La Follette, TN
 Liberty-Clairton, PA
 Logan, UT-ID
 Nogales, AZ
 Provo, UT
 Sacramento, CA
 Salt Lake City, UT
 San Francisco Bay Area, CA

I. BACKGROUND

On December 14, 2009, the EPA initially designated 31 areas as nonattainment for the 2006 24-hour PM2.5 NAAQS, based on the three most recent years (2006-2008) of air monitoring data and other information (74 FR 58688).

On June 2, 2014, the EPA classified as "Moderate" all areas that were designated as nonattainment for the 2006 PM2.5 standards at that time (79 FR 77389). This action includes the following 11 Moderate nonattainment areas for the 2006 PM2.5 NAAQS. Partial counties are identified with "(P)."

    The Chico 2006 24-hour PM2.5 nonattainment area is located in northern California and consists of Butte County (P).  

    The Fairbanks 2006 24-hour PM2.5 nonattainment area is located in central Alaska and consists of Fairbanks North Star Borough (P).  

    The Imperial County 2006 24-hour PM2.5 nonattainment area is located in southeastern California and consists of a portion of Imperial County (P).
   
    The Knoxville-Sevierville-La Follette 2006 24-hour PM2.5 nonattainment area is located in eastern Tennessee and consists of Anderson County, Blount County, Knox County, Loudon County, and Roane County (P).

    The Liberty Clairton 2006 24-hour PM2.5 nonattainment area is located in western Pennsylvania and consists of Allegheny County (P) which includes Lincoln Borough, Clairton City, Glassport Borough, Liberty Borough, and Port Vue Borough.

    The Logan 2006 24-hour PM2.5 nonattainment area is located in southern Idaho and northern Utah and consists of Franklin County, Idaho (P) and Cache County, Utah (P).

    The Nogales 2006 24-hour PM2.5 nonattainment area is located in southern Arizona and consists of a portion of Santa Cruz County (P).

    The Provo 2006 24-hour PM2.5 nonattainment area is located in central Utah and consists of a portion of Utah County (P).

    The Sacramento 2006 24-hour PM2.5 nonattainment area is located in northern California and consists of El Dorado County (P), Placer County (P), Sacramento County, Solano County (P), and Yolo County (P).

    The Salt Lake City 2006 24-hour PM2.5 nonattainment area is located in central Utah and consists of Box Elder County (P), Davis County, Salt Lake County, Tooele County (P) and Weber County (P).

    The San Francisco Bay Area 2006 24-hour PM2.5 nonattainment area is located in northern California and consists of Alameda County, Contra Costa County, Marin County, Napa County, San Francisco County, San Mateo County, Santa Clara County, Solano County (P), and Sonoma County (P).

The individual state maps with the boundaries and counties included in each nonattainment area are available from the EPA's Green Book website at: https://www.epa.gov/green-book. The maps are available for downloading at: https://www3.epa.gov/airquality/greenbook/data_download.html. The list of counties in each of the Moderate nonattainment areas is available at: https://www3.epa.gov/airquality/greenbook/mca.html. For the exact boundaries of the 2006 24-hour PM2.5 nonattainment areas classified as Moderate, go to: https://www3.epa.gov/airquality/greenbook/rmmapa.html.   

II. EVALUATION OF AIR QUALITY MONITORING DATA

To determine if a nonattainment area is attaining the 2006 24-hour PM2.5 NAAQS, one must first calculate the design value (DV) for each eligible monitoring site per (40 CFR part 50, Appendix N, 1.0(c)(2)). The DV for a monitoring site is the average for three consecutive years of the annual 98th percentile 24-hour average PM2.5 mass concentration values recorded at the site. The nonattainment area is attaining the 2006 24-hour PM2.5 NAAQS if all eligible monitoring sites in the area have DV's below the level of the standard. The DV for the nonattainment area is the highest DV for any monitor located in the area.
 
The states with 2006 PM2.5 NAAQS nonattainment areas (identified in List 1 above) submitted quality assured and certified air quality monitoring data to the EPA's Air Quality System (AQS) for calendar years 2013, 2014, and 2015. With the exception of Utah, the states certified that data with a data certification letter sent to the applicable EPA Regional Administrator[,]. For additional information, DV tables for PM2.5 and other pollutants are available on EPA's website at https://www.epa.gov/air-trends/air-quality-design-values. 

III. DATA ANALYSIS AND DETERMINATIONS OF ATTAINMENT

The 2006 24-hour PM2.5 nonattainment areas identified in List 1 above were classified as Moderate for the 2006 24-hour PM2.5 NAAQS. In accordance with section 188(c)(1) of the Clean Air Act (CAA), the applicable statutory attainment date for these areas was as expeditiously as practicable, but no later than December 31, 2015.
   
 EPA's Determinations of Attainment for Nonattainment Areas that have Attained the 2006 24-hour PM2.5 NAAQS by the Applicable Attainment Date

The EPA is proposing to determine, in accordance with section 188(b)(2) of the CAA and the provisions of the EPA's Fine Particulate Matter National Ambient Air Quality Standards:
State Implementation Plan Requirements (81 FR 58010), that seven Moderate nonattainment areas have attained the 2006 24-hour PM2.5 NAAQS by the applicable attainment date of December 31, 2015. This proposed determination is based upon three years of complete, quality-assured and certified data for the years 2013-2015, in accordance with 40 CFR part 50 and as recorded in the EPA's AQS database.

Table 1 lists all seven Moderate areas for which the EPA is proposing a determination of attainment by the December 31, 2015 attainment date. Table 1 also provides the 2013-2015 design values based on requirements of Appendix N, except where otherwise noted. 
                                       
	Table 1 -  2006 24-Hour PM2.5 NAAQS Moderate Nonattainment Areas Qualifying for a Determination of Attainment by the December 31, 2015 Attainment Date
                                       
                                  AQS Site ID
                                  County Name
                                     State
                               98[th] Percentile
                   2013-2015 24-hour Design Value (ug/m[3])
                  2013-2015 24-hour Design Value Valid (Y/N)



                                     2013
                                     2014
                                     2015


                                       
                                   Chico, CA
                                       
                                       
                                   060070008
                                     Butte
                                  California
                                     30.2
                                      26
                                     29.5
                                      29
                                       Y
                                       
                              Imperial County, CA
                                       
                                       
                                   060250005
                                   Imperial
                                  California
                                     27.4
                                     36.3
                                     34.6
                                      33
                                       Y
                                   060250007
                                   Imperial
                                  California
                                     17.2
                                     19.9
                                     12.4
                                      17
                                       Y
                                   060251003
                                   Imperial
                                  California
                                      19
                                     19.6
                                     14.1
                                      18
                                       Y
                                       
                     Knoxville-Sevierville-La Follette, TN
                                       
                                       
                                   470090011
                                    Blount
                                   Tennessee
                                      17
                                     19.1
                                     17.1
                                      18
                                       Y
                                   470930028
                                     Knox
                                   Tennessee
                                     19.1
                                     18.7
                                     19.2
                                      19
                                       Y
                                   470931013
                                     Knox
                                   Tennessee
                                     19.9
                                      17
                                     19.9
                                      19
                                       Y
                                   470931017
                                     Knox
                                   Tennessee
                                     20.2
                                     18.4
                                     20.2
                                      20
                                       Y
                                   470931020
                                     Knox
                                   Tennessee
                                     18.1
                                     18.7
                                     18.2
                                      18
                                       Y
                                   471050108
                                    Loudon
                                   Tennessee
                                      17
                                      18
                                     18.1
                                      18
                                       Y
                                       
                             Liberty-Clairton, PA
                                       
                                       
                                   420030064
                                   Allegheny
                                 Pennsylvania
                                     31.1
                                     32.2
                                     34.9
                                      33
                                       Y
                                   420033007
                                   Allegheny
                                 Pennsylvania
                                     17.1
                                     31.2
                                     25.8
                                      25
                                       Y
                                       
                                  Nogales, AZ
                                       
                                       
                                   040230004
                                  Santa Cruz
                                    Arizona
                                     27.2
                                      29
                                     27.2
                                      28
                                       Y
                                       
                                Sacramento, CA
                                       
                                       
                                   060610003
                                    Placer
                                  California
                                     29.7
                                     22.5
                                      17
                                       23
                                       Y
                                   060610006
                                    Placer
                                  California
                                     18.9
                                     20.6
                                     20.1
                                       20
                                       Y
                                   060670006
                                  Sacramento
                                  California
                                     39.7
                                     28.1
                                     37.8
                                       35
                                       Y
                                   060670010
                                  Sacramento
                                  California
                                     33.4
                                     23.4
                                     32.5
                                       30
                                       Y
                                   060670012
                                  Sacramento
                                  California
                                     21.7
                                     18.1
                                     22.5
                                       
                                       N
                                   060674001
                                  Sacramento
                                  California
                                     35.9
                                      24
                                     29.1
                                      30
                                       Y
                                   061131003
                                     Yolo
                                  California
                                      22
                                     13.2
                                     20.8
                                      19
                                       Y
                                       
                          San Francisco Bay Area, CA
                                       
                                       
                                   060010007
                                    Alameda
                                  California
                                     32.3
                                     25.3
                                     26.5
                                      28
                                       Y
                                   060010009
                                    Alameda
                                  California
                                     27.6
                                     23.6
                                     24.8
                                      25
                                       Y
                                   060010011
                                    Alameda
                                  California
                                      30
                                     25.7
                                     29.9
                                      29
                                       Y
                                   060010012
                                    Alameda
                                  California
                                       
                                     19.1
                                     27.9
                                       
                                       N
                                   060130002
                                 Contra Costa
                                  California
                                     21.7
                                     20.5
                                      28
                                      23
                                       Y
                                   060131004
                                 Contra Costa
                                  California
                                     27.4
                                     23.4
                                     29.6
                                      27
                                       Y
                                   060410001
                                     Marin
                                  California
                                     26.5
                                     20.4
                                     30.5
                                      26
                                       Y
                                   060550003
                                     Napa
                                  California
                                     27.8
                                     23.3
                                      30
                                      27
                                       Y
                                   060750005
                                 San Francisco
                                  California
                                     27.8
                                     20.3
                                     26.6
                                      25
                                       Y
                                   060811001
                                   San Mateo
                                  California
                                     28.5
                                     20.7
                                      22
                                      24
                                       Y
                                   060850002
                                  Santa Clara
                                  California
                                     18.7
                                     16.9
                                     18.5
                                      18
                                       Y
                                   060850005
                                  Santa Clara
                                  California
                                     35.1
                                     27.2
                                     27.4
                                      30
                                       Y
                                   060850006
                                  Santa Clara
                                  California
                                       
                                     20.7
                                     27.5
                                       
                                       N
                                   060950004
                                    Solano
                                  California
                                     32.8
                                     24.4
                                     30.7
                                      29
                                       Y
                                   060970003
                                    Sonoma
                                  California
                                     23.3
                                       
                                       
                                       
                                       N
                                   060970004
                                    Sonoma
                                  California
                                       
                                     17.3
                                     23.1
                                       
                                       N
   
 EPA's Determinations of Failure to Attain by the Attainment Date and Reclassification of Areas to Serious for the 2006 24-hour PM2.5 NAAQS
The EPA is proposing to determine that four areas failed to attain the 2006 24-hour PM2.5 NAAQS by the applicable attainment date of December 31, 2015.  As shown in Table 2 below, at least one monitor in each of these areas had a 2013-2015 design value greater than 35 ug/m[3]. The EPA is therefore proposing to find that these four areas failed to attain the 2006 24-hour PM2.5 NAAQS by the attainment date pursuant to CAA section 188(b)(2), and thus the areas must be reclassified to "Serious" by operation of law.
Table 2: 2006 24-hour PM2.5 NAAQS Moderate Nonattainment Areas That Did Not Attain the 2006 24-hour PM2.5 NAAQS Standard as of December 31, 2015 Attainment Date and Are Subject to Reclassification
                                       
                                       
                                  AQS Site ID
                                  County Name
                                     State
                              98[th] Percentile 
                     2013-2015 Design Value (ug/m[3])[3] 
                     2013-2015 Design Value Valid (Y/N)[4]



                                     2013
                                     2014
                                     2015


                                 Fairbanks, AK
                                       
                                   020900010
                             Fairbanks North Star
                                    Alaska
                                     39.4
                                     34.5
                                     57.1
                                      44
                                       Y
                                   020900033
                             Fairbanks North Star
                                    Alaska
                                     47.2
                                       
                                       
                                       
                                       N
                                   020900034
                             Fairbanks North Star
                                    Alaska
                                     52.7
                                     31.6
                                      60
                                      48
                                       Y
                                   020900035
                             Fairbanks North Star
                                    Alaska
                                     121.6
                                     138.3
                                     111.6
                                      124
                                       Y
                                   020900039
                             Fairbanks North Star
                                    Alaska
                                       
                                     78.4
                                     52.3
                                       
                                       N
                                       
                                 Logan, UT-ID*
                                       
                                       
                                   160410001
                                   Franklin
                                     Idaho
                                       
                                       
                                     18.8
                                       
                                       N
                                   490050004
                                     Cache
                                     Utah
                                     73.7
                                     41.1
                                     33.8
                                      50
                                       Y
                                   490050007
                                     Cache
                                     Utah
                                       
                                       
                                     32.7
                                       
                                       N
                                       
                                 Provo, UT[*]
                                       
                                       
                                   490490002
                                     Utah
                                     Utah
                                     81.8
                                      30
                                     25.8
                                      46
                                       Y
                                   490494001
                                     Utah
                                     Utah
                                      91
                                     29.7
                                     26.9
                                       49
                                       Y
                                   490495010
                                     Utah
                                     Utah
                                     84.6
                                     28.7
                                     22.4
                                       45
                                       Y
                                       
                             Salt Lake City, UT[*]
                                       
                                       
                                   490030003
                                   Box Elder
                                     Utah
                                     53.5
                                     35.8
                                     33.5
                                      41
                                       Y
                                   490110004
                                     Davis
                                     Utah
                                     45.6
                                     45.9
                                     19.4
                                      37
                                       Y
                                   490351001
                                   Salt Lake
                                     Utah
                                     40.3
                                     46.3
                                     22.7
                                      36
                                       Y
                                   490353006
                                   Salt Lake
                                     Utah
                                     58.8
                                     46.2
                                     25.3
                                      43
                                       Y
                                   490353010
                                   Salt Lake
                                     Utah
                                     52.1
                                     48.7
                                     34.6
                                      45
                                       Y
                                   490450003
                                    Tooele
                                     Utah
                                     43.9
                                     29.4
                                       
                                       
                                       N
                                   490570002
                                     Weber
                                     Utah
                                     46.7
                                     32.4
                                     22.1
                                      34
                                       Y
                                   490571003
                                     Weber
                                     Utah
                                     45.8
                                       
                                       
                                       
                                       N
*Data submitted to the EPA's AQS by the Utah Department of Environmental Quality for the period 2013-2015 are incomplete, meaning there are fewer than 75 percent of the necessary data required for completion. However, the valid data provided by the state and submitted to AQS for 2013-2015 show a DV greater than 35 ug/m[3]. The EPA's regulations governing the use of air quality data for regulatory purposes, located at 40 CFR part 50, Appendix N 4.2(b), specify that 24-hour PM2.5 DVs derived from less than complete data are valid if greater than the level of the standard. The EPA is thus basing this proposal on its determination that sufficient data exist to make findings of failure to attain and reclassifications for all Utah nonattainment areas. The EPA calculated the DVs for these areas using the available PM2.5 Federal Reference Method (FRM) data in AQS as of September 21, 2016. These DVs may change as data validation efforts to include additional monitoring data are completed by Utah. A memo describing the agency's treatment of these data, titled "Utah PM2.5 2013-2015 24-hour Design Concentrations Memo," is included in the docket for this rulemaking.
