Quiero saber acerca de...

Federal Register / Vol. 86, No. 33 / Monday, February 22, 2021 / Proposed Rules precursors as they apply in the Fairbanks PM2.5 Nonattainment Area.
Alaska DEC also added definitions for the terms catalytic oxidizer, charbroiler, chain-driven charbroiler, and used oil to support the new information collection requirements for small area sources in 18 AAC 50.078.39
The added and revised definitions in 18 AAC 50.990 are consistent with Clean Air Act requirements, therefore, we propose to approve and incorporate the submitted revised definitions by reference into the Alaska SIP.
h. Emergency Episode Plan EPA approved the Fairbanks Emergency Episode Plan as meeting certain Moderate area control strategy requirements on September 8, 2017 82
FR 42457. EPA subsequently approved the plan for purposes of CAA section 110a2G requirements for the 2006
24-hour PM2.5 NAAQS November 28, 2018, 83 FR 60769. Alaska revised the Fairbanks Emergency Episode Plan and submitted the updated plan as part of the Fairbanks Serious Plan submission on December 13, 2019. However, EPA
did not act on the Fairbanks Serious Plan version, and Alaska has since revised the Emergency Episode Plan and submitted the updates for approval on December 15, 2020. EPAs most recent
approval of the Fairbanks Emergency Episode Plan Volume II, Section III.D.5.11 occurred on June 5, 2019 84
FR 26019.
As noted previously, on December 15, 2020, Alaska submitted an updated Fairbanks Emergency Episode Plan as it applies to the Fairbanks PM2.5
Nonattainment Area Volume II, Section III.D.7.12. Generally, the submitted plan strengthens the solid fuel burning device curtailment program implemented via 18 AAC 50.075e and makes the control measures within this emissions source category more stringent. The submitted plan includes lower more stringent thresholds for air quality episodes and advisory/alerts, along with updated exceptions that have a limited duration and incentivize upgrading heating devices.
In particular, Alaska revised the Air Quality Episode Thresholds and Exceptions used to declare the two-stage curtailment program. Both of the alert stages were lowered by 5 micrograms per cubic meter mg/m3 in this submission. The Stage 1 Air Alert requires solid fuel burning devices to cease operation once PM2.5
concentrations exceed 20 mg/m3.40 The Emergency Episode Plan provides an exception during periods of power outage Volume II, Section III.D.7.12, Table 7.121. Otherwise, operation of a
10519

solid fuel burning device during an air quality episode is prohibited unless the device qualifies for a temporary waiver.
Operation of a solid fuel burning device during the Stage 1 Air Alert is allowed only if the device meets certain qualifications and conditions see Volume II, Section III.D.7.12, Table 7.126 of the Fairbanks Serious Plan.
Specifically, the waiver is limited in duration and requires older devices to be replaced in order to maintain the waiver. The Stage 2 Air Alert requires solid fuel burning devices to cease operation once PM2.5 concentrations rise above 30 micrograms per cubic meter mg/m3. Waivers for Stage 1 and Stage 2 Alerts are provided for a device owner or operator that qualifies for a No Other Adequate Source of Heat NOASH
waiver see Volume II, Section III.D.7.12, Table 7.125 of the Fairbanks Serious Plan, but these waivers are also limited in duration and require older devices to be replaced in order to maintain the waiver. The Fairbanks Emergency Episode Plan included in the December 15, 2020, submission includes a control measure that will take effect upon an EPA finding under 40 CFR 51.1014a Stage 2 Air Alert Contingency Measure. If triggered, the control measure will lower the Stage 2
Air Alert threshold from 30 mg/m3 to 25
mg/m3. See Table 1 below.

TABLE 1ALASKAS TABLE 7.121 AIR QUALITY EPISODE THRESHOLDS AND EXCEPTIONS
Episode feature
Stage 1 air alert
Stage 2 air alert
PM2.5 Threshold, micrograms per cubic meter, g/m3
Exceptions During a Power Outage

20
Yes

30
Yes

tkelley on DSKBCP9HB2PROD with PROPOSALS

The Fairbanks Emergency Episode Plan also includes Air Advisories that allow Alaska to request voluntary curtailment actions prior to reaching PM2.5 concentrations that trigger the Air Alerts and mandatory curtailment requirements. Air Advisories are declared when PM2.5 concentrations exceed 15 mg/m3 24-hour rolling average. The Air Advisory was lowered by 5 mg/m3 in this submission. See Table 2 below.

39 Alaska requested approval of this new regulation in the Fairbanks Serious Plan submission.
40 According to the Emergency Episode Plan, ADEC air quality specialists use an air quality forecasting tool called the AQ Alert Model to issue forecasted curtailments by 2:00 p.m. local time.
Before declaring a curtailment on the operation of
VerDate Sep<11>2014

18:29 Feb 19, 2021

Jkt 253001

TABLE 2ALASKAS TABLE 7.123
ADVISORY/ALERT LEVEL
Type
24-hour average PM2.5
concentration g/m3

Advisory Alert

15

Alaskas revisions to the Fairbanks Emergency Episode Plan improve the States ability to implement the solid fuel burning device curtailment program via 18 AAC 50.075e and make the related control measures more stringent.
Specifically, the revised PM2.5
solid fuel-fired heating devices, DEC reviews the relevant and available meteorological data, weather forecasts, affected area, strength of the inversion, and potential duration of the inversion. Other inputs include the afternoon forecast of dispersion conditions issued by the National Weather Service forecasting office in Fairbanks and the assessment by ADEC personnel of many factors based on their
PO 00000

Frm 00061

Fmt 4702

Sfmt 4702

Stage 2 air alert contingency measure 25.
Yes.

thresholds for the two-stage program will result in reduced emissions from solid fuel burning devices, particularly during the winter months. Therefore, we propose to approve and incorporate Volume II, Section III.D.7.12 of the State Air Quality Control Plan by reference into the Alaska SIP. As stated earlier, EPA is proposing to approve the Fairbanks Emergency Episode Plan as SIP strengthening and is not proposing to determine whether the Plan satisfies, in whole or in part, the control strategy requirements in CAA section 189 and 40
CFR 51.1010 or the contingency long-standing experience in observing air quality in Fairbanks, including the rate of change in concentrations at the monitors and the location and movement of weather fronts seen in satellite photos.
DEC sometimes calls an Alert that does not include a curtailment if weather conditions indicate a clearing prior to any impact of a curtailment taking effect.

E:FRFM22FEP1.SGM

22FEP1