Voglio sapere a riguardo di…

Federal Register / Vol. 86, No. 232 / Tuesday, December 7, 2021 / Proposed Rules SUPPLEMENTARY INFORMATION:
Throughout this document we, us, or our means EPA.

Table of Contents I. Background A. The 2010 SO2 NAAQS
B. Designations and Attainment Dates for the 2010 SO2 NAAQS
C. Louisianas Nonattainment SIP Revision II. Proposed Determination A. Applicable Statutory and Regulatory Provisions B. Monitoring Network Considerations C. Data Considerations and Proposed Determination a. Monitor Data b. Modeling Data c. Record of Compliance d. EPAs Proposed Determination III. Proposed Action IV. Statutory and Executive Order Reviews
lotter on DSK11XQN23PROD with PROPOSALS1

I. Background A. The 2010 SO2 NAAQS
Under section 109 of the Act, the EPA
has established primary and secondary NAAQS for certain pervasive air pollutants referred to as criteria pollutants and conducts periodic reviews of the NAAQS to determine whether they should be revised or whether new NAAQS should be established. The primary NAAQS
represent ambient air quality standards the attainment and maintenance of which the EPA has determined, including a margin of safety, are requisite to protect the public health.
The secondary NAAQS represent ambient air quality standards the attainment and maintenance of which the EPA has determined are requisite to protect the public welfare from any known or anticipated adverse effects associated with the presence of such air pollutant in the ambient air.
Under the CAA, the EPA must establish NAAQS for criteria pollutants, including SO2. SO2 is primarily released to the atmosphere through the burning of fossil fuels by power plants and other industrial facilities. SO2 is also emitted from industrial processes including metal extraction from ore and heavy equipment that burn fuel with a high sulfur content. Short-term exposure to SO2 can damage the human respiratory system and increase breathing difficulties. Small children and people with respiratory conditions, such as asthma, are more sensitive to the effects of SO2. Sulfur oxides at high concentrations in ambient air can also react with compounds to form small particulates that can penetrate deeply into the lungs and cause health problems.
The EPA first established primary SO2
standards in 1971 at 0.14 parts per
VerDate Sep<11>2014

16:37 Dec 06, 2021

Jkt 256001

million ppm over a 24-hour averaging period and 0.3 ppm over an annual averaging period.1 In June 2010, the EPA revised the NAAQS for SO2 to provide increased protection of public health, providing for revocation of the 1971 primary annual and 24-hour SO2
standards for most areas of the country following area designations under the new NAAQS.2 The primary 2010 SO2
NAAQS is 75 parts per billion ppb, or 0.075 ppm, over a one-hour averaging period.3 A violation of the 2010 onehour SO2 NAAQS occurs when the annual 99th percentile of ambient daily maximum one-hour average SO2
concentrations, averaged over a 3-year period, exceeds 75 ppb.4
B. Designations and Attainment Dates for the 2010 SO2 NAAQS
Following promulgation of any new or revised NAAQS, the EPA is required by CAA section 107d to designate areas throughout the nation as attaining or not attaining the NAAQS. On August 5, 2013, the EPA finalized its first round of designations for the 2010 primary SO2 NAAQS.5 In this 2013 action, the EPA designated 29 areas in 16 states as nonattainment for the 2010 SO2
NAAQS, including the St. Bernard area in Louisiana. The EPA designated the St. Bernard area nonattainment based on certified monitoring data for years 2009
through 2011.6 The EPAs initial round of designations for the 2010 SO2
NAAQS including the St. Bernard area became effective on October 4, 2013.
Pursuant to CAA section 192a, the maximum attainment date for the St.
Bernard area was October 4, 2018, five years after the effective date of the final action designating the area as nonattainment for the 2010 SO2
NAAQS.
C. Louisianas Nonattainment SIP
Revision Section 172c of the CAA lists the required components of a nonattainment plan submittal. In addition to an attainment demonstration, the nonattainment plan addresses the requirements for meeting reasonable further progress RFP
toward attainment of the NAAQS, implementation of reasonably available control measures and reasonably available control technology RACM/
RACT, base-year and projection-year emission inventories, a new source 1 See
36 FR 8186 April 30, 1971.
40 CFR 50.4e.
3 See 75 FR 35520 June 22, 2010.
4 See 40 CFR 50.17.
5 See 78 FR 47191 August 5, 2013.
6 See 78 FR 47191, codified at 40 CFR part 81, subpart C.
2 See
PO 00000

Frm 00031

Fmt 4702

Sfmt 4702

69211

review permit program, enforceable emissions limitations and control measures, and contingency measures.
The attainment demonstration includes a modeling analysis showing that the enforceable emissions limitations and other control measures taken by the state will provide for RFP and expeditious attainment of the NAAQS
section 172c2, 4, 6, and 7.
On November 9, 2017, the Louisiana Department of Environmental Quality LDEQ submitted a nonattainment area SIP for the St. Bernard Parish area. On February 8, 2018, LDEQ submitted a letter to the EPA, accompanied by an Administrative Order on Consent AOC, dated February 2, 2018, executed between LDEQ and the Rain CII Carbon, LLC Rain facility, that included new emissions limits for the Rain facilitys cold stack and hot stack/pyroscrubber, as well as monitoring, testing and recordkeeping requirements. LDEQ
submitted this as a source specific SIP
revision and supplement to the 2017
nonattainment area SIP. Rain is a coke calcining operation that includes a waste heat recovery boiler. During normal operations, the exhaust from the calcining operation is routed through the recovery boiler and then through a scrubber and finally to the atmosphere through what is termed the cold stack. During start up and times when the recovery boiler is down, emissions are routed to the atmosphere through what is known as the hot stack. The modeling covers three operation scenarios: Cold stack only operation, hot stack only operation, and a transitional period with emissions through both stacks. The transition period from hot stack to cold stack occurs in a phased approach, gradually routing more and more exhaust to the cold stack from the hot stack until all exhaust is routed to the cold stack. The emission limits in the AOC included all operation regimes at the facility, with differing emission limits depending on the stage of operation defined by a minimum or range of flowrates and stack temperatures of the cold and hot stacks.
On April 19, 2018, we published a proposed rulemaking action to approve the 2010 SO2 Primary NAAQS
Nonattainment Area SIP revision for St.
Bernard Parish.7 The April 19, 2018
action proposed approval of the following CAA SIP elements: The attainment demonstration for the SO2
NAAQS; enforceable emissions limits including the AOC dated February 2, 2018, for the Rain facility; RFP plan;
RACM and RACT demonstrations;
emission inventories; and contingency 7 See
E:FRFM07DEP1.SGM

83 FR 17349 April 19, 2018.

07DEP1