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Federal Register / Vol. 86, No. 33 / Monday, February 22, 2021 / Proposed Rules
sources in the 2013 inventory.
Additional home heating survey data collected in winters 2012 through 2015
were used by the State to augment the estimates of residential space heating device/fuel mix and usage in the Moderate Plan based on the singular 2011 Home Heating survey. The State combined this broader sample of survey data to better reflect residential space heating activity within the nonattainment area for calendar year 2013. For both on-road and non-road vehicles, the State used EPAs latest vehicle emissions model, MOVES2014b, to replace emission estimates from the Moderate SIP based on its predecessor, MOVES2010a. Alaska used MOVES2014b emission factors based on local fleet/fuel characteristics and augmented with Fairbanks North Star Borough wintertime vehicle warmup and plug-in emission testing data. Onroad vehicle activity VMT and speeds was based by the State on 2013 baseline
travel demand model outputs from the Fairbanks Metropolitan Area Transportation System FMATS 2040
Metropolitan Transportation Plan MTP
and 2045 MTP. Alaska used the 2014
National Emissions Inventory to represent Source Classification Code SCC-level annual emissions for fugitive dust, which were estimated to have no emissions during episodic wintertime conditions.
The 2013 base year emissions inventory in the Fairbanks Serious Plan has its foundations in the emissions inventory development work conducted for the Moderate Plan, which was based on emission estimates for two historical calendar year 2008 episodes January 23February 10, 2008 and November 2
17, 2008. The Fairbanks North Star Borough, Alaska Department of Environmental Conservation, and EPA
collectively determined that these seasonal modeling episodes typify atmospheric/meteorological conditions
and source activity/emission patterns within the nonattainment season when ambient PM2.5 concentrations exceed the standard at design day or high percentile levels.16 Alaska believes that the average of emissions across the combined 35 days of the two historical episodes are well suited not just for attainment modeling, but also to satisfy seasonal planning inventory requirements. Similar to their development of a base year inventory for their Moderate Area Plan, Alaska used the meteorological scenarios and modeling from 2008 historical episodes as the basis for generating their 2013
base year planning inventory within this Serious SIP as provided in the PM2.5 SIP
Requirements Rule.
Table 1 in this preamble provides a summary of the episodic 24-hour average inventories in tons per day tpd of direct PM2.5 and PM2.5 precursors NOX, SO2, VOC, and ammonia for the 2013 base year.

TABLE 1FAIRBANKS PM2.5 NONATTAINMENT AREA 2013 BASE YEAR EPISODE AVERAGE DAILY EMISSIONS tons/day BY
SOURCE SECTOR
Source sector
Direct PM2.5

NOX

SO2

VOC

Ammonia
Point Sources
Area, Space Heating Total
Area, Space Heat, Wood
Area, Space Heat, Oil
Area, Space Heat, Coal
Area, Space Heat, Other
Area, Other 1
On-Road Mobile
Non-Road Mobile 2

1.23
2.59
2.43
0.06
0.08
0.01
0.22
0.27
0.15

10.45
2.34
0.40
1.72
0.05
0.16
1.72
3.36
0.86

7.22
3.62
0.08
3.42
0.10
0.02
0.03
0.02
6.10

0.23
9.50
9.29
0.10
0.11
0.01
2.27
4.07
0.41

0.051
0.136
0.091
0.003
0.013
0.028
0.045
0.054
0.000

Totals

4.46

18.73

17.00

16.48

0.286

Source: Fairbanks Serious Plan, Chapter III.D.7.6, Table 7.610.
1 The Area, Other category includes minor stationary sources e.g., asphalt plants, coffee roasters, etc.
2 The non-road mobile category includes recreational vehicles, logging equipment, agricultural equipment, etc.

The 2013 base year emissions inventory meets the requirements of CAA section 172c3 and 40 CFR
51.1008. Calendar year 2013 is an appropriate base year for the Fairbanks Serious Plan because it is one of the three years used in the reclassification from a Moderate area to a Serious area.
The base year emissions inventory is a seasonal inventory, based on two meteorological episodes exemplifying the range of meteorological conditions that lead to exceedances of the 24-hour NAAQS. This is an appropriate temporal scope for a base year emissions inventory where anthropogenic
exceedances of the 24-hour NAAQS are exclusively in winter.
The emissions inventory is of actual emissions in 2013, as required in the PM2.5 SIP Requirements Rule and guidance.17 The emissions inventory also includes separate reporting for filterable and condensible PM2.5 for the relevant emissions sectors and SCC
codes. The base year 2013 emissions inventory is based on methodologies used by the State and vetted by EPA in the Fairbanks Moderate Plan and applied to the new year 2013. Therefore, the inventory reports emissions of point sources consistent with the Air Emissions Reporting Rule AERR and contains the detail and data elements
16 The inventory is based on emissions estimated during the two 2008 episodes that represent weather conditions when exceedances of the 2006
24-hour PM2.5 NAAQS typically occur. The
inventory is an average of emissions across all days in the two episodes. It represents the average season-day emissions, in which the emission inventory season is the wintertime episodes of cold
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required by 40 CFR part 51, subpart A.
For these reasons, we are proposing to approve the 2013 base year emissions inventory in the Fairbanks Serious Plan as meeting the requirements of CAA
section 172c3 and 40 CFR 51.1008.
B. PM2.5 Precursor Demonstration 1. Statutory and Regulatory Requirements Under subpart 4 of part D, title I of the CAA and the PM2.5 SIP Requirements Rule, each state containing a PM2.5
nonattainment area must evaluate all PM2.5 precursors for regulation unless, for any given PM2.5 precursor, the state demonstrates to the Administrators satisfaction that such precursor does not and calm weather that coincide with exceedances of the standard 82 FR 9035, February 2, 2017.
17 40 CFR 51.1008a1ii.

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