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Federal Register / Vol. 86, No. 183 / Friday, September 24, 2021 / Proposed Rules
been the 24-hour PM2.5 design value site. An assessment of long-term trends at the ClovisVilla monitoring site and a nearby monitoring site shows that the ClovisVilla site has historically had design values below the 24-hour PM2.5
NAAQS and has had lower design values compared to the nearby site.
During the 2011 to 2019 period, the ClovisVilla monitoring site consistently had lower design values for the 24-hour PM2.5 NAAQS than the FresnoGarland monitoring site, which is located approximately four miles from ClovisVilla.282 The Fresno Garland site has a complete 2020 annual 24-hour design value below the 1997 24hour PM2.5 NAAQS and provides an appropriate comparison and characterization of air quality for the area surrounding the ClovisVilla monitoring site. Furthermore, the District exceeds the PM2.5 minimum monitoring requirements for three PM2.5
SLAMs monitors in the Fresno MSA as
they are currently operating five SLAMs monitors.
Thus, based on the historical design value concentrations at the ClovisVilla monitoring site relative to the 24-hour PM2.5 NAAQS and the nearest site, we find that the incomplete data at the ClovisVilla monitoring site should not preclude the EPA from determining the San Joaquin Valley area has attained the 1997 24-hour PM2.5 NAAQS.
Table 5 shows the 24-hour PM2.5
design values at each of the 18 SLAMS
monitoring sites within the San Joaquin Valley nonattainment area for the most recent three-year period 20182020.
The data indicate that the San Joaquin Valley area likely experienced higher than normal PM2.5 concentrations in 2018 and 2020 due to wildfire impacts during the summer and fall months.283
Table 5 shows that 98th percentile concentrations at all 18 monitors in the San Joaquin Valley area with data spanning 2018 to 2020 are significantly higher in 2018 and 2020 relative to
concentrations in 2019, again, likely due to the wildfires in those years.
Accordingly, the 20182020 design values in Table 5 may also be higher than normal at certain monitoring sites due to potential wildfire impacts within the 20182020 data period.
Nevertheless, the data show that the 24hour design value for the 20182020
period was equal to or less than 65
mg/m3 i.e., the level of the 1997 24-hour PM2.5 NAAQS at all monitors after excluding monitored exceedances specifically associated with the August 2024, 2020 wildfire exceptional event, as discussed below. Therefore, we are proposing to determine, based on complete or otherwise not inconsistent, as described above, quality-assured, and certified data for 20182020, that the San Joaquin Valley area has attained the 1997 24-hour PM2.5 NAAQS, consistent with attainment of the standard projected by the State in the SJV PM2.5 Plan.

TABLE 520182020 24-HOUR PM2.5 DESIGN VALUES FOR THE SAN JOAQUIN VALLEY NONATTAINMENT AREA
98th percentile g/m3
County
General location site
Fresno

Kern

Kings
Madera
Merced
San Joaquin
Stanislaus
Tulare

2020

20182020
24-hour design values g/m3

61.
62.
64 Inv.a 62 Inv.b 54.
55.
64.
61.
64.
64.
54.
53.
53.
64.
59 Inv.d 65.
64.
64.

AQS ID

FresnoPacific
FresnoGarland
FresnoFoundry
ClovisVilla
Tranquillity
BakersfieldAirport Planz
BakersfieldCalifornia Ave
BakersfieldGolden State Highway
CorcoranPatterson
HanfordIrwin
MaderaAvenue 14
MercedM Street
MercedCoffee
StocktonHazelton
Manteca
Modesto14th Street
Turlock
Visalia

060195025
060190011
060192016
060195001
060192009
060290016
060290014
060290010
060310004
060311004
060392010
060472510
060470003
060771002
060772010
060990005
060990006
061072002

2018

2019

65.5
63.5
Inc
57.0
51.4
60.8
69.2
60.9
78.0
78.2
50.2
52.7
56.0
92.3
84.6 c
100.4
88.6
63.4

37.1
36.9
Inc
28.0 Inc
17.1
46.7
43.4
44.3
45.1
41.1
23.9
29.5
23.4
32.9
26.8 Inc
28.4
36.0
45.5

81.0
85.0
63.9
99.5
92.5
57.1
79.2
76.9
69.0
72.6
87.7
77.1
78.3
65.9
66.9
67.1
67.7
83.4

Source: EPA, 2020 AQS Design Value Report, AMP480, accessed September 1, 2021.The Design Value Report excludes measurements with regionally concurred exceptional event flags. AQS reports for 24-hour PM2.5 data are only available for the 2006 24-hour PM2.5 NAAQS as a Pollutant Standard, thus this report only reflects the 2006 24-hour PM2.5 NAAQS and does not include the 1997 24-hour PM2.5 NAAQS as a Pollutant Standard. Subsequently, AQS only allows the EPA to place concurrence flags on data associated with the 2006 24-hour PM2.5 NAAQS. 40
CFR part 50 Appendix N specifies the data handling and design value calculations for both the 2006 24-hour PM2.5 NAAQS and the 1997 24hour PM2.5 NAAQS. The design values in the Design Value Report for the 2006 24-hr PM2.5 NAAQS for the San Joaquin Valley nonattainment area are the same as would be expected for the 1997 24-hr PM2.5 NAAQS if the exceptional events for that NAAQS were correctly represented in AQS.
Notes: Inc = Incomplete data. Inv = Invalid design value due to incomplete data.
a The 20182020 design value at FresnoFoundry AQS ID: 060192016 is based on concentration data from January 1, 2020 to December 31, 2020. The site began operation in 2020; therefore, data from January 1, 2018 to December 31, 2019 are not available. Based on 40 CFR
part 50, Appendix N, section 4.2b, three years of valid annual PM2.5 98th percentile mass concentrations are required to produce a valid 24hour PM2.5 NAAQS design value. Thus, the FresnoFoundry 20182020 design value is considered invalid.
b Based on the design value calculation methodologies described in 40 CFR part 50, Appendix N, section 4.2b, the ClovisVilla AQS ID: 06
0195001 20182020 design value is considered invalid due to incomplete data in the 2nd, 3rd, and 4th quarters of 2019.

282 The ClovisVilla and FresnoGarland monitoring sites have the same 2020 design value of 62 mg/m3.

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283 EPA, 2020 Raw Data Report, AMP350, accessed July 13, 2021.

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